An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.
Cell surface proteins that bind cyclic AMP with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized cyclic AMP receptors are those of the slime mold Dictyostelium discoideum. The transcription regulator CYCLIC AMP RECEPTOR PROTEIN of prokaryotes is not included nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES.
A cyclic nucleotide derivative that mimics the action of endogenous CYCLIC AMP and is capable of permeating the cell membrane. It has vasodilator properties and is used as a cardiac stimulant. (From Merck Index, 11th ed)
A transcriptional regulator in prokaryotes which, when activated by binding cyclic AMP, acts at several promoters. Cyclic AMP receptor protein was originally identified as a catabolite gene activator protein. It was subsequently shown to regulate several functions unrelated to catabolism, and to be both a negative and a positive regulator of transcription. Cell surface cyclic AMP receptors are not included (CYCLIC AMP RECEPTORS), nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins, which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES.
Enzymes that catalyze the hydrolysis of CYCLIC AMP to form adenosine 5'-phosphate. The enzymes are widely distributed in animal tissue and control the level of intracellular cyclic AMP. Many specific enzymes classified under this heading demonstrate additional spcificity for 3',5'-cyclic IMP and CYCLIC GMP.
A potent cyclic nucleotide phosphodiesterase inhibitor; due to this action, the compound increases cyclic AMP and cyclic GMP in tissue and thereby activates CYCLIC NUCLEOTIDE-REGULATED PROTEIN KINASES
Potent activator of the adenylate cyclase system and the biosynthesis of cyclic AMP. From the plant COLEUS FORSKOHLII. Has antihypertensive, positive inotropic, platelet aggregation inhibitory, and smooth muscle relaxant activities; also lowers intraocular pressure and promotes release of hormones from the pituitary gland.
A methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac and central nervous system stimulant activities. Theophylline inhibits the 3',5'-CYCLIC NUCLEOTIDE PHOSPHODIESTERASE that degrades CYCLIC AMP thus potentiates the actions of agents that act through ADENYLYL CYCLASES and cyclic AMP.
An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.
An enzyme that catalyzes the deamination of AMP to IMP. EC 3.5.4.6.
Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.
Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position.
A long-acting derivative of cyclic AMP. It is an activator of cyclic AMP-dependent protein kinase, but resistant to degradation by cyclic AMP phosphodiesterase.
Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases.
A protein that has been shown to function as a calcium-regulated transcription factor as well as a substrate for depolarization-activated CALCIUM-CALMODULIN-DEPENDENT PROTEIN KINASES. This protein functions to integrate both calcium and cAMP signals.
Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed)
A phosphodiesterase 4 inhibitor with antidepressant properties.
The rate dynamics in chemical or physical systems.
The increase in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.
A group of enzymes that are dependent on CYCLIC AMP and catalyze the phosphorylation of SERINE or THREONINE residues on proteins. Included under this category are two cyclic-AMP-dependent protein kinase subtypes, each of which is defined by its subunit composition.
(11 alpha,13E,15S)-11,15-Dihydroxy-9-oxoprost-13-en-1-oic acid (PGE(1)); (5Z,11 alpha,13E,15S)-11,15-dihydroxy-9-oxoprosta-5,13-dien-1-oic acid (PGE(2)); and (5Z,11 alpha,13E,15S,17Z)-11,15-dihydroxy-9-oxoprosta-5,13,17-trien-1-oic acid (PGE(3)). Three of the six naturally occurring prostaglandins. They are considered primary in that no one is derived from another in living organisms. Originally isolated from sheep seminal fluid and vesicles, they are found in many organs and tissues and play a major role in mediating various physiological activities.
An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells, and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Cyclic nucleotides are closed-chain molecules formed from nucleotides (ATP or GTP) through the action of enzymes called cyclases, functioning as second messengers in various cellular signaling pathways, with cAMP and cGMP being the most prominent members.
A class of enzymes that catalyze the hydrolysis of one of the two ester bonds in a phosphodiester compound. EC 3.1.4.
A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.
The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.
A 29-amino acid pancreatic peptide derived from proglucagon which is also the precursor of intestinal GLUCAGON-LIKE PEPTIDES. Glucagon is secreted by PANCREATIC ALPHA CELLS and plays an important role in regulation of BLOOD GLUCOSE concentration, ketone metabolism, and several other biochemical and physiological processes. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1511)
Purine bases found in body tissues and fluids and in some plants.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.
A potent vasodilator agent that increases peripheral blood flow.
One of the virulence factors produced by virulent BORDETELLA organisms. It is a bifunctional protein with both ADENYLYL CYCLASES and hemolysin components.
Systems in which an intracellular signal is generated in response to an intercellular primary messenger such as a hormone or neurotransmitter. They are intermediate signals in cellular processes such as metabolism, secretion, contraction, phototransduction, and cell growth. Examples of second messenger systems are the adenyl cyclase-cyclic AMP system, the phosphatidylinositol diphosphate-inositol triphosphate system, and the cyclic GMP system.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
N-Isopropyl-N-phenyl-adenosine. Antilipemic agent. Synonym: TH 162.
2-Chloroadenosine. A metabolically stable analog of adenosine which acts as an adenosine receptor agonist. The compound has a potent effect on the peripheral and central nervous system.
Established cell cultures that have the potential to propagate indefinitely.
An alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. It is a direct-acting smooth muscle relaxant used in the treatment of impotence and as a vasodilator, especially for cerebral vasodilation. The mechanism of its pharmacological actions is not clear, but it apparently can inhibit phosphodiesterases and it may have direct actions on calcium channels.
Inhibitor of phosphodiesterases.
A genus of protozoa, formerly also considered a fungus. Its natural habitat is decaying forest leaves, where it feeds on bacteria. D. discoideum is the best-known species and is widely used in biomedical research.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
A group of compounds that are derivatives of oxo-pyrrolidines. A member of this group is 2-oxo pyrrolidine, which is an intermediate in the manufacture of polyvinylpyrrolidone. (From Merck Index, 11th ed)
A drug combination that contains THEOPHYLLINE and ethylenediamine. It is more soluble in water than theophylline but has similar pharmacologic actions. It's most common use is in bronchial asthma, but it has been investigated for several other applications.
A set of BACTERIAL ADHESINS and TOXINS, BIOLOGICAL produced by BORDETELLA organisms that determine the pathogenesis of BORDETELLA INFECTIONS, such as WHOOPING COUGH. They include filamentous hemagglutinin; FIMBRIAE PROTEINS; pertactin; PERTUSSIS TOXIN; ADENYLATE CYCLASE TOXIN; dermonecrotic toxin; tracheal cytotoxin; Bordetella LIPOPOLYSACCHARIDES; and tracheal colonization factor.
One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS.
N-(1-Oxobutyl)-cyclic 3',5'-(hydrogen phosphate)-2'-butanoate guanosine. A derivative of cyclic GMP. It has a higher resistance to extracellular and intracellular phosphodiesterase than cyclic GMP.
Nucleotides in which the base moiety is substituted with one or more sulfur atoms.
A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.
The most common and most biologically active of the mammalian prostaglandins. It exhibits most biological activities characteristic of prostaglandins and has been used extensively as an oxytocic agent. The compound also displays a protective effect on the intestinal mucosa.
A cyclic nucleotide phosphodiesterase subfamily that is found predominantly in inflammatory cells and may play a role in the regulation of CELL-MEDIATED IMMUNITY. The enzyme family includes over twenty different variants that occur due to multiple ALTERNATIVE SPLICING of the mRNA of at least four different genes.
Cyclic AMP response element modulator is a basic leucine zipper transcription factor that is regulated by CYCLIC AMP. It plays an important role in SPERMATID development in the mammalian TESTIS.
A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors (RECEPTORS, VASOACTIVE INTESTINAL PEPTIDE).
A stable adenosine A1 and A2 receptor agonist. Experimentally, it inhibits cAMP and cGMP phosphodiesterase activity.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
Drugs that selectively bind to and activate beta-adrenergic receptors.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
One of the virulence factors produced by BORDETELLA PERTUSSIS. It is a multimeric protein composed of five subunits S1 - S5. S1 contains mono ADPribose transferase activity.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Elements of limited time intervals, contributing to particular results or situations.
Phosphoric acid esters of inositol. They include mono- and polyphosphoric acid esters, with the exception of inositol hexaphosphate which is PHYTIC ACID.
A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.
Cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. The two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. Adrenergic receptors may also be classified according to the subtypes of G-proteins with which they bind; this scheme does not respect the alpha-beta distinction.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.
An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Twenty-carbon compounds derived from MEVALONIC ACID or deoxyxylulose phosphate.
A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
Nucleoside-2',3'-cyclic phosphate nucleotidohydrolase. Enzymes that catalyze the hydrolysis of the 2'- or 3'- phosphate bonds of 2',3'-cyclic nucleotides. Also hydrolyzes nucleoside monophosphates. Includes EC 3.1.4.16 and EC 3.1.4.37. EC 3.1.4.-.
An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.
A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes.
A class of glucosyltransferases that catalyzes the degradation of storage polysaccharides, such as glucose polymers, by phosphorolysis in animals (GLYCOGEN PHOSPHORYLASE) and in plants (STARCH PHOSPHORYLASE).
An anterior pituitary hormone that stimulates the ADRENAL CORTEX and its production of CORTICOSTEROIDS. ACTH is a 39-amino acid polypeptide of which the N-terminal 24-amino acid segment is identical in all species and contains the adrenocorticotrophic activity. Upon further tissue-specific processing, ACTH can yield ALPHA-MSH and corticotrophin-like intermediate lobe peptide (CLIP).
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
A dideoxynucleoside compound in which the 3'-hydroxy group on the sugar moiety has been replaced by a hydrogen. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. The compound is an inhibitor of HIV replication, acting as a chain-terminator of viral DNA by binding to reverse transcriptase. Its principal side effect is nephrotoxicity. In vivo, dideoxyadenosine is rapidly metabolized to DIDANOSINE (ddI) by enzymatic deamination; ddI is then converted to dideoxyinosine monophosphate and ultimately to dideoxyadenosine triphosphate, the putative active metabolite.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).
Cell surface proteins that bind PURINES with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized classes of purinergic receptors in mammals are the P1 receptors, which prefer ADENOSINE, and the P2 receptors, which prefer ATP or ADP.
Tritium is an isotope of hydrogen (specifically, hydrogen-3) that contains one proton and two neutrons in its nucleus, making it radioactive with a half-life of about 12.3 years, and is used in various applications including nuclear research, illumination, and dating techniques due to its low energy beta decay.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.
Inosine 5'-(tetrahydrogen triphosphate). An inosine nucleotide containing three phosphate groups esterified to the sugar moiety. Synonym: IRPPP.
The action of a drug in promoting or enhancing the effectiveness of another drug.
Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.
A cyclic nucleotide phosphodiesterase subfamily that is inhibited by the binding of CYCLIC GMP to an allosteric domain found on the enzyme and through phosphorylation by regulatory kinases such as PROTEIN KINASE A and PROTEIN KINASE B. The two members of this family are referred to as type 3A, and type 3B, and are each product of a distinct gene. In addition multiple enzyme variants of each subtype can be produced due to multiple alternative mRNA splicing.
A compound composed of a two CYCLIC PEPTIDES attached to a phenoxazine that is derived from STREPTOMYCES parvullus. It binds to DNA and inhibits RNA synthesis (transcription), with chain elongation more sensitive than initiation, termination, or release. As a result of impaired mRNA production, protein synthesis also declines after dactinomycin therapy. (From AMA Drug Evaluations Annual, 1993, p2015)
A phorbol ester found in CROTON OIL with very effective tumor promoting activity. It stimulates the synthesis of both DNA and RNA.
An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.
Catalyze the hydrolysis of nucleotides with the elimination of ammonia.
A class of cell surface receptors that prefer ADENOSINE to other endogenous PURINES. Purinergic P1 receptors are widespread in the body including the cardiovascular, respiratory, immune, and nervous systems. There are at least two pharmacologically distinguishable types (A1 and A2, or Ri and Ra).
A class of histamine receptors discriminated by their pharmacology and mode of action. Histamine H2 receptors act via G-proteins to stimulate ADENYLYL CYCLASES. Among the many responses mediated by these receptors are gastric acid secretion, smooth muscle relaxation, inotropic and chronotropic effects on heart muscle, and inhibition of lymphocyte function. (From Biochem Soc Trans 1992 Feb;20(1):122-5)
Antidiuretic hormones released by the NEUROHYPOPHYSIS of all vertebrates (structure varies with species) to regulate water balance and OSMOLARITY. In general, vasopressin is a nonapeptide consisting of a six-amino-acid ring with a cysteine 1 to cysteine 6 disulfide bridge or an octapeptide containing a CYSTINE. All mammals have arginine vasopressin except the pig with a lysine at position 8. Vasopressin, a vasoconstrictor, acts on the KIDNEY COLLECTING DUCTS to increase water reabsorption, increase blood volume and blood pressure.
Inorganic salts of phosphoric acid.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to the hexahydroxy alcohol, myo-inositol. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid, myo-inositol, and 2 moles of fatty acids.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
A peptide hormone of about 27 amino acids from the duodenal mucosa that activates pancreatic secretion and lowers the blood sugar level. (USAN and the USP Dictionary of Drug Names, 1994, p597)
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
That phase of a muscle twitch during which a muscle returns to a resting position.
An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.
Adenine nucleotides are molecules that consist of an adenine base attached to a ribose sugar and one, two, or three phosphate groups, including adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP), which play crucial roles in energy transfer and signaling processes within cells.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
A histamine H2 receptor antagonist that is used as an anti-ulcer agent.
Derivatives of BUTYRIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxypropane structure.
A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
'Purines' is a term used in medical biochemistry to refer to naturally occurring heterocyclic aromatic organic compounds, which include adenine and guanine (components of nucleotides and nucleic acids), and are formed in the body from purine bases through various metabolic processes.
A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.
Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)
Drugs that bind to but do not activate histamine receptors, thereby blocking the actions of histamine or histamine agonists. Classical antihistaminics block the histamine H1 receptors only.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
A group of compounds with the heterocyclic ring structure of benzo(c)pyridine. The ring structure is characteristic of the group of opium alkaloids such as papaverine. (From Stedman, 25th ed)
Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.
A highly vascularized endocrine gland consisting of two lobes joined by a thin band of tissue with one lobe on each side of the TRACHEA. It secretes THYROID HORMONES from the follicular cells and CALCITONIN from the parafollicular cells thereby regulating METABOLISM and CALCIUM level in blood, respectively.
LIPOLYSIS of stored LIPIDS in the ADIPOSE TISSUE to release FREE FATTY ACIDS. Mobilization of stored lipids is under the regulation of lipolytic signals (CATECHOLAMINES) or anti-lipolytic signals (INSULIN) via their actions on the hormone-sensitive LIPASE. This concept does not include lipid transport.
A purine base and a fundamental unit of ADENINE NUCLEOTIDES.
Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.
Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.
A source of inorganic fluoride which is used topically to prevent dental caries.
A CALCIUM and CALMODULIN-dependent cyclic nucleotide phosphodiesterase subfamily. The three members of this family are referred to as type 1A, type 1B, and type 1C and are each product of a distinct gene. In addition, multiple enzyme variants of each subtype can be produced due to multiple alternative mRNA splicing. Although the type 1 enzymes are classified as 3',5'-cyclic-AMP phosphodiesterases (EC 3.1.4.17), some members of this class have additional specificity for CYCLIC GMP.
A glycoprotein hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Thyrotropin stimulates THYROID GLAND by increasing the iodide transport, synthesis and release of thyroid hormones (THYROXINE and TRIIODOTHYRONINE). Thyrotropin consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the pituitary glycoprotein hormones (TSH; LUTEINIZING HORMONE and FSH), but the beta subunit is unique and confers its biological specificity.
'Sugar phosphates' are organic compounds that consist of a sugar molecule linked to one or more phosphate groups, playing crucial roles in biochemical processes such as energy transfer and nucleic acid metabolism.
A division of organisms that exist vegetatively as complex mobile plasmodia, reproduce by means of spores, and have complex life cycles. They are now classed as protozoa but formerly were considered fungi.
The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.
The outer layer of the adrenal gland. It is derived from MESODERM and comprised of three zones (outer ZONA GLOMERULOSA, middle ZONA FASCICULATA, and inner ZONA RETICULARIS) with each producing various steroids preferentially, such as ALDOSTERONE; HYDROCORTISONE; DEHYDROEPIANDROSTERONE; and ANDROSTENEDIONE. Adrenal cortex function is regulated by pituitary ADRENOCORTICOTROPIN.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
Fluids originating from the epithelial lining of the intestines, adjoining exocrine glands and from organs such as the liver, which empty into the cavity of the intestines.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.
A major alkaloid from Colchicum autumnale L. and found also in other Colchicum species. Its primary therapeutic use is in the treatment of gout, but it has been used also in the therapy of familial Mediterranean fever (PERIODIC DISEASE).
Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS.
A genetically related subfamily of RAP GTP-BINDING PROTEINS that share homology with RAS PROTEINS. They bind to Ras effectors but do not activate them, therefore they may antagonize the effects of RAS PROTEINS. This enzyme was formerly listed as EC 3.6.1.47.
An enzyme that catalyzes the phosphorylation of AMP to ADP in the presence of ATP or inorganic triphosphate. EC 2.7.4.3.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The decrease in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.
An eicosanoid, derived from the cyclooxygenase pathway of arachidonic acid metabolism. It is a stable and synthetic analog of EPOPROSTENOL, but with a longer half-life than the parent compound. Its actions are similar to prostacyclin. Iloprost produces vasodilation and inhibits platelet aggregation.
An anti-inflammatory 9-fluoro-glucocorticoid.
An enzyme that catalyzes the conversion of D-fructose 1,6-bisphosphate and water to D-fructose 6-phosphate and orthophosphate. EC 3.1.3.11.
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A non-steroidal anti-inflammatory agent (NSAID) that inhibits the enzyme cyclooxygenase necessary for the formation of prostaglandins and other autacoids. It also inhibits the motility of polymorphonuclear leukocytes.
Compounds that bind to and stimulate PURINERGIC P1 RECEPTORS.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
A phenothiazine with actions similar to CHLORPROMAZINE. It is used as an antipsychotic and an antiemetic.
Enzymes that catalyze the hydrolysis of cyclic GMP to yield guanosine-5'-phosphate.
An alpha-adrenergic sympathomimetic amine, biosynthesized from tyramine in the CNS and platelets and also in invertebrate nervous systems. It is used to treat hypotension and as a cardiotonic. The natural D(-) form is more potent than the L(+) form in producing cardiovascular adrenergic responses. It is also a neurotransmitter in some invertebrates.
A glycoprotein enzyme present in various organs and in many cells. The enzyme catalyzes the hydrolysis of a 5'-ribonucleotide to a ribonucleoside and orthophosphate in the presence of water. It is cation-dependent and exists in a membrane-bound and soluble form. EC 3.1.3.5.
A pair of glands located at the cranial pole of each of the two KIDNEYS. Each adrenal gland is composed of two distinct endocrine tissues with separate embryonic origins, the ADRENAL CORTEX producing STEROIDS and the ADRENAL MEDULLA producing NEUROTRANSMITTERS.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
An enzyme that catalyzes the conversion of L-TYROSINE and 2-oxoglutarate to 4-hydroxyphenylpyruvate and L-GLUTAMATE. It is a pyridoxal-phosphate protein. L-PHENYLALANINE is hydroxylated to L-tyrosine. The mitochondrial enzyme may be identical with ASPARTATE AMINOTRANSFERASES (EC 2.6.1.1.). Deficiency of this enzyme may cause type II Tyrosinemia (see TYROSINEMIAS). EC 2.6.1.5.
Physiologically active prostaglandins found in many tissues and organs. They show pressor activity, are mediators of inflammation, and have potential antithrombotic effects.

The MAP kinase ERK2 inhibits the cyclic AMP-specific phosphodiesterase HSPDE4D3 by phosphorylating it at Ser579. (1/18083)

The extracellular receptor stimulated kinase ERK2 (p42(MAPK))-phosphorylated human cAMP-specific phosphodiesterase PDE4D3 at Ser579 and profoundly reduced ( approximately 75%) its activity. These effects could be reversed by the action of protein phosphatase PP1. The inhibitory state of PDE4D3, engendered by ERK2 phosphorylation, was mimicked by the Ser579-->Asp mutant form of PDE4D3. In COS1 cells transfected to express PDE4D3, challenge with epidermal growth factor (EGF) caused the phosphorylation and inhibition of PDE4D3. This effect was blocked by the MEK inhibitor PD98059 and was not apparent using the Ser579-->Ala mutant form of PDE4D3. Challenge of HEK293 and F442A cells with EGF led to the PD98059-ablatable inhibition of endogenous PDE4D3 and PDE4D5 activities. EGF challenge of COS1 cells transfected to express PDE4D3 increased cAMP levels through a process ablated by PD98059. The activity of the Ser579-->Asp mutant form of PDE4D3 was increased by PKA phosphorylation. The transient form of the EGF-induced inhibition of PDE4D3 is thus suggested to be due to feedback regulation by PKA causing the ablation of the ERK2-induced inhibition of PDE4D3. We identify a novel means of cross-talk between the cAMP and ERK signalling pathways whereby cell stimuli that lead to ERK2 activation may modulate cAMP signalling.  (+info)

The paired-domain transcription factor Pax8 binds to the upstream enhancer of the rat sodium/iodide symporter gene and participates in both thyroid-specific and cyclic-AMP-dependent transcription. (2/18083)

The gene encoding the Na/I symporter (NIS) is expressed at high levels only in thyroid follicular cells, where its expression is regulated by the thyroid-stimulating hormone via the second messenger, cyclic AMP (cAMP). In this study, we demonstrate the presence of an enhancer that is located between nucleotides -2264 and -2495 in the 5'-flanking region of the NIS gene and that recapitulates the most relevant aspects of NIS regulation. When fused to either its own or a heterologous promoter, the NIS upstream enhancer, which we call NUE, stimulates transcription in a thyroid-specific and cAMP-dependent manner. The activity of NUE depends on the four most relevant sites, identified by mutational analysis. The thyroid-specific transcription factor Pax8 binds at two of these sites. Mutations that interfere with Pax8 binding also decrease transcriptional activity of the NUE. Furthermore, expression of Pax8 in nonthyroid cells results in transcriptional activation of NUE, strongly suggesting that the paired-domain protein Pax8 plays an important role in NUE activity. The NUE responds to cAMP in both protein kinase A-dependent and -independent manners, indicating that this enhancer could represent a novel type of cAMP responsive element. Such a cAMP response requires Pax8 but also depends on the integrity of a cAMP responsive element (CRE)-like sequence, thus suggesting a functional interaction between Pax8 and factors binding at the CRE-like site.  (+info)

Identification of a cAMP response element within the glucose- 6-phosphatase hydrolytic subunit gene promoter which is involved in the transcriptional regulation by cAMP and glucocorticoids in H4IIE hepatoma cells. (3/18083)

The expression of a luciferase reporter gene under the control of the human glucose 6-phosphatase gene promoter was stimulated by both dexamethasone and dibutyryl cAMP in H4IIE hepatoma cells. A cis-active element located between nucleotides -161 and -152 in the glucose 6-phosphatase gene promoter was identified and found to be necessary for both basal reporter-gene expression and induction of expression by both dibutyryl cAMP and dexamethasone. Nucleotides -161 to -152 were functionally replaced by the consensus sequence for a cAMP response element. An antibody against the cAMP response element-binding protein caused a supershift in gel-electrophoretic-mobility-shift assays using an oligonucleotide probe representing the glucose 6-phosphatase gene promoter from nucleotides -161 to -152. These results strongly indicate that in H4IIE cells the glucose 6-phosphatase gene-promoter sequence from -161 to -152 is a cAMP response element which is important for the regulation of transcription of the glucose 6-phosphatase gene by both cAMP and glucocorticoids.  (+info)

PrKX is a novel catalytic subunit of the cAMP-dependent protein kinase regulated by the regulatory subunit type I. (4/18083)

The human X chromosome-encoded protein kinase X (PrKX) belongs to the family of cAMP-dependent protein kinases. The catalytically active recombinant enzyme expressed in COS cells phosphorylates the heptapeptide Kemptide (LRRASLG) with a specific activity of 1.5 micromol/(min.mg). Using surface plasmon resonance, high affinity interactions were demonstrated with the regulatory subunit type I (RIalpha) of cAMP-dependent protein kinase (KD = 10 nM) and the heat-stable protein kinase inhibitor (KD = 15 nM), but not with the type II regulatory subunit (RIIalpha, KD = 2.3 microM) under physiological conditions. Kemptide and autophosphorylation activities of PrKX are strongly inhibited by the RIalpha subunit and by protein kinase inhibitor in vitro, but only weakly by the RIIalpha subunit. The inhibition by the RIalpha subunit is reversed by addition of nanomolar concentrations of cAMP (Ka = 40 nM), thus demonstrating that PrKX is a novel, type I cAMP-dependent protein kinase that is activated at lower cAMP concentrations than the holoenzyme with the Calpha subunit of cAMP-dependent protein kinase. Microinjection data clearly indicate that the type I R subunit but not type II binds to PrKX in vivo, preventing the translocation of PrKX to the nucleus in the absence of cAMP. The RIIalpha subunit is an excellent substrate for PrKX and is phosphorylated in vitro in a cAMP-independent manner. We discuss how PrKX can modulate the cAMP-mediated signal transduction pathway by preferential binding to the RIalpha subunit and by phosphorylating the RIIalpha subunit in the absence of cAMP.  (+info)

A2B adenosine and P2Y2 receptors stimulate mitogen-activated protein kinase in human embryonic kidney-293 cells. cross-talk between cyclic AMP and protein kinase c pathways. (5/18083)

Mitogen-activated protein kinase (MAPK) cascades underlie long-term mitogenic, morphogenic, and secretory activities of purinergic receptors. In HEK-293 cells, N-ethylcarboxamidoadenosine (NECA) activates endogenous A2BARs that signal through Gs and Gq/11. UTP activates P2Y2 receptors and signals only through Gq/11. The MAPK isoforms, extracellular-signal regulated kinase 1/2 (ERK), are activated by NECA and UTP. H-89 blocks ERK activation by forskolin, but weakly affects the response to NECA or UTP. ERK activation by NECA or UTP is unaffected by a tyrosine kinase inhibitor (genistein), attenuated by a phospholipase C inhibitor (U73122), and is abolished by a MEK inhibitor (PD098059) or dominant negative Ras. Inhibition of protein kinase C (PKC) by GF 109203X failed to block ERK activation by NECA or UTP, however, another PKC inhibitor, Ro 31-8220, which unlike GF 109203X, can block the zeta-isoform, and prevents UTP- but not NECA-induced ERK activation. In the presence of forskolin, Ro 31-8220 loses its ability to block UTP-stimulated ERK activation. PKA has opposing effects on B-Raf and c-Raf-1, both of which are found in HEK-293 cells. The data are explained by a model in which ERK activity is modulated by differential effects of PKC zeta and PKA on Raf isoforms.  (+info)

CRE-mediated gene transcription in neocortical neuronal plasticity during the developmental critical period. (6/18083)

Neuronal activity-dependent processes are believed to mediate the formation of synaptic connections during neocortical development, but the underlying intracellular mechanisms are not known. In the visual system, altering the pattern of visually driven neuronal activity by monocular deprivation induces cortical synaptic rearrangement during a postnatal developmental window, the critical period. Here, using transgenic mice carrying a CRE-lacZ reporter, we demonstrate that a calcium- and cAMP-regulated signaling pathway is activated following monocular deprivation. We find that monocular deprivation leads to an induction of CRE-mediated lacZ expression in the visual cortex preceding the onset of physiologic plasticity, and this induction is dramatically downregulated following the end of the critical period. These results suggest that CRE-dependent coordinate regulation of a network of genes may control physiologic plasticity during postnatal neocortical development.  (+info)

Prior exposure to neurotrophins blocks inhibition of axonal regeneration by MAG and myelin via a cAMP-dependent mechanism. (7/18083)

MAG is a potent inhibitor of axonal regeneration. Here, inhibition by MAG, and myelin in general, is blocked if neurons are exposed to neurotrophins before encountering the inhibitor; priming cerebellar neurons with BDNF or GDNF, but not NGF, or priming DRG neurons with any of these neurotrophins blocks inhibition by MAG/myelin. Dibutyryl cAMP also overcomes inhibition by MAG/myelin, and cAMP is elevated by neurotrophins. A PKA inhibitor present during priming abrogates the block of inhibition. Finally, if neurons are exposed to MAG/myelin and neurotrophins simultaneously, but with the Gi protein inhibitor, inhibition is blocked. We suggest that priming neurons with particular neurotrophins elevates cAMP and activates PKA, which blocks subsequent inhibition of regeneration and that priming is required because MAG/myelin activates a Gi protein, which blocks increases in cAMP. This is important for encouraging axons to regrow in vivo.  (+info)

Mechanisms for generating the autonomous cAMP-dependent protein kinase required for long-term facilitation in Aplysia. (8/18083)

The formation of a persistently active cAMP-dependent protein kinase (PKA) is critical for establishing long-term synaptic facilitation (LTF) in Aplysia. The injection of bovine catalytic (C) subunits into sensory neurons is sufficient to produce protein synthesis-dependent LTF. Early in the LTF induced by serotonin (5-HT), an autonomous PKA is generated through the ubiquitin-proteasome-mediated proteolysis of regulatory (R) subunits. The degradation of R occurs during an early time window and appears to be a key function of proteasomes in LTF. Lactacystin, a specific proteasome inhibitor, blocks the facilitation induced by 5-HT, and this block is rescued by injecting C subunits. R is degraded through an allosteric mechanism requiring an elevation of cAMP coincident with the induction of a ubiquitin carboxy-terminal hydrolase.  (+info)

Cyclic adenosine monophosphate (cAMP) is a key secondary messenger in many biological processes, including the regulation of metabolism, gene expression, and cellular excitability. It is synthesized from adenosine triphosphate (ATP) by the enzyme adenylyl cyclase and is degraded by the enzyme phosphodiesterase.

In the body, cAMP plays a crucial role in mediating the effects of hormones and neurotransmitters on target cells. For example, when a hormone binds to its receptor on the surface of a cell, it can activate a G protein, which in turn activates adenylyl cyclase to produce cAMP. The increased levels of cAMP then activate various effector proteins, such as protein kinases, which go on to regulate various cellular processes.

Overall, the regulation of cAMP levels is critical for maintaining proper cellular function and homeostasis, and abnormalities in cAMP signaling have been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Cyclic AMP (Adenosine Monophosphate) receptors are a type of membrane receptor that play an essential role in intracellular signaling pathways. They belong to the family of G protein-coupled receptors (GPCRs), which are characterized by their seven transmembrane domains.

Cyclic AMP is a second messenger, a molecule that relays signals from hormones and neurotransmitters within cells. When an extracellular signaling molecule binds to the receptor, it activates a G protein, which in turn triggers the enzyme adenylyl cyclase to convert ATP into cAMP. The increased levels of cAMP then activate various downstream effectors, such as protein kinases, ion channels, and transcription factors, ultimately leading to changes in cellular function.

There are two main types of cAMP receptors: stimulatory G protein-coupled receptors (Gs) and inhibitory G protein-coupled receptors (Gi). The activation of Gs receptors leads to an increase in cAMP levels, while the activation of Gi receptors results in a decrease in cAMP levels.

Examples of hormones and neurotransmitters that act through cAMP receptors include adrenaline, glucagon, dopamine, serotonin, and histamine. Dysregulation of cAMP signaling has been implicated in various diseases, including cancer, cardiovascular disease, and neurological disorders.

I apologize for the confusion, but "Bucladesine" is not a recognized medical term or a medication in current use in medicine. It's possible that there may be some mistake or typo in the spelling. If you have any more context about where you encountered this term, I might be able to provide a more accurate and helpful response.

Cyclic AMP (Adenosine Monophosphate) Receptor Protein, also known as Cyclic AMP-dependent Protein Kinase (PKA), is a crucial intracellular signaling molecule that mediates various cellular responses. PKA is a serine/threonine protein kinase that gets activated by the binding of cyclic AMP to its regulatory subunits, leading to the release and activation of its catalytic subunits.

Once activated, the catalytic subunit of PKA phosphorylates various target proteins, including enzymes, ion channels, and transcription factors, thereby modulating their activities. This process plays a vital role in regulating numerous physiological processes such as metabolism, gene expression, cell growth, differentiation, and apoptosis.

The dysregulation of PKA signaling has been implicated in various pathological conditions, including cancer, cardiovascular diseases, neurodegenerative disorders, and diabetes. Therefore, understanding the molecular mechanisms underlying PKA activation and regulation is essential for developing novel therapeutic strategies to treat these diseases.

3',5'-Cyclic-AMP (cyclic adenosine monophosphate) phosphodiesterases are a group of enzymes that catalyze the breakdown of cyclic AMP to 5'-AMP. These enzymes play a crucial role in regulating the levels of intracellular second messengers, such as cyclic AMP, which are involved in various cellular signaling pathways.

There are several subtypes of phosphodiesterases (PDEs) that specifically target cyclic AMP, including PDE1, PDE2, PDE3, PDE4, PDE7, PDE8, and PDE10. Each subtype has distinct regulatory and catalytic properties, allowing for specific regulation of cyclic AMP levels in different cellular compartments and signaling pathways.

Inhibition of these enzymes can lead to an increase in intracellular cyclic AMP levels, which can have therapeutic effects in various diseases, such as cardiovascular disease, pulmonary hypertension, and central nervous system disorders. Therefore, PDE inhibitors are a valuable class of drugs for the treatment of these conditions.

1-Methyl-3-isobutylxanthine is a chemical compound that belongs to the class of xanthines. It is a methylated derivative of xanthine and is commonly found in some types of tea, coffee, and chocolate. This compound acts as a non-selective phosphodiesterase inhibitor, which means it can increase the levels of intracellular cyclic AMP (cAMP) by preventing its breakdown.

In medical terms, 1-Methyl-3-isobutylxanthine is often used as a bronchodilator and a stimulant of central nervous system. It is also known to have diuretic properties. This compound is sometimes used in the treatment of asthma, COPD (chronic obstructive pulmonary disease), and other respiratory disorders.

It's important to note that 1-Methyl-3-isobutylxanthine can have side effects, including increased heart rate, blood pressure, and anxiety. It should be used under the supervision of a medical professional and its use should be carefully monitored to avoid potential adverse reactions.

Colforsin is a drug that belongs to a class of medications called phosphodiesterase inhibitors. It works by increasing the levels of a chemical called cyclic AMP (cyclic adenosine monophosphate) in the body, which helps to relax and widen blood vessels.

Colforsin is not approved for use in humans in many countries, including the United States. However, it has been used in research settings to study its potential effects on heart function and other physiological processes. In animals, colforsin has been shown to have positive inotropic (contractility-enhancing) and lusitropic (relaxation-enhancing) effects on the heart, making it a potential therapeutic option for heart failure and other cardiovascular conditions.

It is important to note that while colforsin has shown promise in preclinical studies, more research is needed to establish its safety and efficacy in humans. Therefore, it should only be used under the supervision of a qualified healthcare professional and in the context of a clinical trial or research study.

Theophylline is a medication that belongs to a class of drugs called methylxanthines. It is used in the management of respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and other conditions that cause narrowing of the airways in the lungs.

Theophylline works by relaxing the smooth muscle around the airways, which helps to open them up and make breathing easier. It also acts as a bronchodilator, increasing the flow of air into and out of the lungs. Additionally, theophylline has anti-inflammatory effects that can help reduce swelling in the airways and relieve symptoms such as coughing, wheezing, and shortness of breath.

Theophylline is available in various forms, including tablets, capsules, and liquid solutions. It is important to take this medication exactly as prescribed by a healthcare provider, as the dosage may vary depending on individual factors such as age, weight, and liver function. Regular monitoring of blood levels of theophylline is also necessary to ensure safe and effective use of the medication.

Adenylate cyclase is an enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP). It plays a crucial role in various cellular processes, including signal transduction and metabolism. Adenylate cyclase is activated by hormones and neurotransmitters that bind to G-protein-coupled receptors on the cell membrane, leading to the production of cAMP, which then acts as a second messenger to regulate various intracellular responses. There are several isoforms of adenylate cyclase, each with distinct regulatory properties and subcellular localization.

AMP deaminase is an enzyme that is responsible for the conversion of adenosine monophosphate (AMP) to inosine monophosphate (IMP), which is a part of the purine nucleotide cycle. This enzyme plays a crucial role in energy metabolism, particularly in muscles during exercise. A deficiency in AMP deaminase has been linked to muscle fatigue and weakness.

Isoproterenol is a medication that belongs to a class of drugs called beta-adrenergic agonists. Medically, it is defined as a synthetic catecholamine with both alpha and beta adrenergic receptor stimulating properties. It is primarily used as a bronchodilator to treat conditions such as asthma and chronic obstructive pulmonary disease (COPD) by relaxing the smooth muscles in the airways, thereby improving breathing.

Isoproterenol can also be used in the treatment of bradycardia (abnormally slow heart rate), cardiac arrest, and heart blocks by increasing the heart rate and contractility. However, due to its non-selective beta-agonist activity, it may cause various side effects such as tremors, palpitations, and increased blood pressure. Its use is now limited due to the availability of more selective and safer medications.

Adenosine monophosphate (AMP) is a nucleotide that is the monophosphate ester of adenosine, consisting of the nitrogenous base adenine attached to the 1' carbon atom of ribose via a β-N9-glycosidic bond, which in turn is esterified to a phosphate group. It is an important molecule in biological systems as it plays a key role in cellular energy transfer and storage, serving as a precursor to other nucleotides such as ADP and ATP. AMP is also involved in various signaling pathways and can act as a neurotransmitter in the central nervous system.

8-Bromo Cyclic Adenosine Monophosphate (8-Br-cAMP) is a synthetic, cell-permeable analog of cyclic adenosine monophosphate (cAMP). Cyclic AMP is an important second messenger in many signal transduction pathways, and 8-Br-cAMP is often used in research to mimic or study the effects of increased cAMP levels. The bromine atom at the 8-position makes 8-Br-cAMP more resistant to degradation by phosphodiesterases, allowing it to have a longer duration of action compared to cAMP. It is used in various biochemical and cellular studies as a tool compound to investigate the role of cAMP in different signaling pathways.

Phosphodiesterase inhibitors (PDE inhibitors) are a class of drugs that work by blocking the action of phosphodiesterase enzymes, which are responsible for breaking down cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), two crucial intracellular signaling molecules.

By inhibiting these enzymes, PDE inhibitors increase the concentration of cAMP and cGMP in the cells, leading to a variety of effects depending on the specific type of PDE enzyme that is inhibited. These drugs have been used in the treatment of various medical conditions such as erectile dysfunction, pulmonary arterial hypertension, and heart failure.

Examples of PDE inhibitors include sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra) for erectile dysfunction, and iloprost, treprostinil, and sildenafil for pulmonary arterial hypertension. It's important to note that different PDE inhibitors have varying levels of selectivity for specific PDE isoforms, which can result in different therapeutic effects and side effect profiles.

CREB (Cyclic AMP Response Element-Binding Protein) is a transcription factor that plays a crucial role in regulating gene expression in response to various cellular signals. CREB binds to the cAMP response element (CRE) sequence in the promoter region of target genes and regulates their transcription.

When activated, CREB undergoes phosphorylation at a specific serine residue (Ser-133), which leads to its binding to the coactivator protein CBP/p300 and recruitment of additional transcriptional machinery to the promoter region. This results in the activation of target gene transcription.

CREB is involved in various cellular processes, including metabolism, differentiation, survival, and memory formation. Dysregulation of CREB has been implicated in several diseases, such as cancer, neurodegenerative disorders, and mood disorders.

Cyclic guanosine monophosphate (cGMP) is a important second messenger molecule that plays a crucial role in various biological processes within the human body. It is synthesized from guanosine triphosphate (GTP) by the enzyme guanylyl cyclase.

Cyclic GMP is involved in regulating diverse physiological functions, such as smooth muscle relaxation, cardiovascular function, and neurotransmission. It also plays a role in modulating immune responses and cellular growth and differentiation.

In the medical field, changes in cGMP levels or dysregulation of cGMP-dependent pathways have been implicated in various disease states, including pulmonary hypertension, heart failure, erectile dysfunction, and glaucoma. Therefore, pharmacological agents that target cGMP signaling are being developed as potential therapeutic options for these conditions.

Rolipram is not a medical term per se, but it is the name of a pharmaceutical compound. Rolipram is a selective inhibitor of phosphodiesterase-4 (PDE4), an enzyme that plays a role in regulating the body's inflammatory response and is involved in various cellular signaling pathways.

Rolipram has been investigated as a potential therapeutic agent for several medical conditions, including depression, asthma, chronic obstructive pulmonary disease (COPD), and Alzheimer's disease. However, its development as a drug has been hindered by issues related to its pharmacokinetics, such as poor bioavailability and a short half-life, as well as side effects like nausea and emesis.

Therefore, while Rolipram is an important compound in the field of pharmacology and has contributed significantly to our understanding of PDE4's role in various physiological processes, it is not typically used as a medical term to describe a specific disease or condition.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

A chemical stimulation in a medical context refers to the process of activating or enhancing physiological or psychological responses in the body using chemical substances. These chemicals can interact with receptors on cells to trigger specific reactions, such as neurotransmitters and hormones that transmit signals within the nervous system and endocrine system.

Examples of chemical stimulation include the use of medications, drugs, or supplements that affect mood, alertness, pain perception, or other bodily functions. For instance, caffeine can chemically stimulate the central nervous system to increase alertness and decrease feelings of fatigue. Similarly, certain painkillers can chemically stimulate opioid receptors in the brain to reduce the perception of pain.

It's important to note that while chemical stimulation can have therapeutic benefits, it can also have adverse effects if used improperly or in excessive amounts. Therefore, it's essential to follow proper dosing instructions and consult with a healthcare provider before using any chemical substances for stimulation purposes.

Cyclic AMP (cAMP)-dependent protein kinases, also known as protein kinase A (PKA), are a family of enzymes that play a crucial role in intracellular signaling pathways. These enzymes are responsible for the regulation of various cellular processes, including metabolism, gene expression, and cell growth and differentiation.

PKA is composed of two regulatory subunits and two catalytic subunits. When cAMP binds to the regulatory subunits, it causes a conformational change that leads to the dissociation of the catalytic subunits. The freed catalytic subunits then phosphorylate specific serine and threonine residues on target proteins, thereby modulating their activity.

The cAMP-dependent protein kinases are activated in response to a variety of extracellular signals, such as hormones and neurotransmitters, that bind to G protein-coupled receptors (GPCRs) or receptor tyrosine kinases (RTKs). These signals lead to the activation of adenylyl cyclase, which catalyzes the conversion of ATP to cAMP. The resulting increase in intracellular cAMP levels triggers the activation of PKA and the downstream phosphorylation of target proteins.

Overall, cAMP-dependent protein kinases are essential regulators of many fundamental cellular processes and play a critical role in maintaining normal physiology and homeostasis. Dysregulation of these enzymes has been implicated in various diseases, including cancer, diabetes, and neurological disorders.

Prostaglandin E (PGE) is a type of prostaglandin, which is a group of lipid compounds that are synthesized in the body from fatty acids and have diverse hormone-like effects. Prostaglandins are not actually hormones, but are similar to them in that they act as chemical messengers that have specific effects on certain cells.

Prostaglandin E is one of the most abundant prostaglandins in the body and has a variety of physiological functions. It is involved in the regulation of inflammation, pain perception, fever, and smooth muscle contraction. Prostaglandin E also plays a role in the regulation of blood flow, platelet aggregation, and gastric acid secretion.

Prostaglandin E is synthesized from arachidonic acid, which is released from cell membranes by the action of enzymes called phospholipases. Once formed, prostaglandin E binds to specific receptors on the surface of cells, leading to a variety of intracellular signaling events that ultimately result in changes in cell behavior.

Prostaglandin E is used medically in the treatment of several conditions, including dysmenorrhea (painful menstruation), postpartum hemorrhage, and patent ductus arteriosus (a congenital heart defect). It is also used as a diagnostic tool in the evaluation of kidney function.

Cholera toxin is a protein toxin produced by the bacterium Vibrio cholerae, which causes the infectious disease cholera. The toxin is composed of two subunits, A and B, and its primary mechanism of action is to alter the normal function of cells in the small intestine.

The B subunit of the toxin binds to ganglioside receptors on the surface of intestinal epithelial cells, allowing the A subunit to enter the cell. Once inside, the A subunit activates a signaling pathway that results in the excessive secretion of chloride ions and water into the intestinal lumen, leading to profuse, watery diarrhea, dehydration, and other symptoms associated with cholera.

Cholera toxin is also used as a research tool in molecular biology and immunology due to its ability to modulate cell signaling pathways. It has been used to study the mechanisms of signal transduction, protein trafficking, and immune responses.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Cyclic nucleotides are formed by the intramolecular phosphoester bond between the phosphate group and the hydroxyl group at the 3'-carbon atom of the ribose sugar in a nucleotide. This creates a cyclic structure, specifically a cyclic phosphate. The most common cyclic nucleotides are cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). These molecules function as second messengers in cells, playing crucial roles in various cellular signaling pathways related to metabolism, gene expression, and cell differentiation. The levels of cAMP and cGMP are tightly regulated by the activities of enzymes such as adenylate cyclase and guanylate cyclase for their synthesis, and phosphodiesterases for their degradation.

Phosphoric diester hydrolases are a class of enzymes that catalyze the hydrolysis of phosphoric diester bonds. These enzymes are also known as phosphatases or nucleotidases. They play important roles in various biological processes, such as signal transduction, metabolism, and regulation of cellular activities.

Phosphoric diester hydrolases can be further classified into several subclasses based on their substrate specificity and catalytic mechanism. For example, alkaline phosphatases (ALPs) are a group of phosphoric diester hydrolases that preferentially hydrolyze phosphomonoester bonds in a variety of organic molecules, releasing phosphate ions and alcohols. On the other hand, nucleotidases are a subclass of phosphoric diester hydrolases that specifically hydrolyze the phosphodiester bonds in nucleotides, releasing nucleosides and phosphate ions.

Overall, phosphoric diester hydrolases are essential for maintaining the balance of various cellular processes by regulating the levels of phosphorylated molecules and nucleotides.

Adenosine is a purine nucleoside that is composed of a sugar (ribose) and the base adenine. It plays several important roles in the body, including serving as a precursor for the synthesis of other molecules such as ATP, NAD+, and RNA.

In the medical context, adenosine is perhaps best known for its use as a pharmaceutical agent to treat certain cardiac arrhythmias. When administered intravenously, it can help restore normal sinus rhythm in patients with paroxysmal supraventricular tachycardia (PSVT) by slowing conduction through the atrioventricular node and interrupting the reentry circuit responsible for the arrhythmia.

Adenosine can also be used as a diagnostic tool to help differentiate between narrow-complex tachycardias of supraventricular origin and those that originate from below the ventricles (such as ventricular tachycardia). This is because adenosine will typically terminate PSVT but not affect the rhythm of VT.

It's worth noting that adenosine has a very short half-life, lasting only a few seconds in the bloodstream. This means that its effects are rapidly reversible and generally well-tolerated, although some patients may experience transient symptoms such as flushing, chest pain, or shortness of breath.

Epinephrine, also known as adrenaline, is a hormone and a neurotransmitter that is produced in the body. It is released by the adrenal glands in response to stress or excitement, and it prepares the body for the "fight or flight" response. Epinephrine works by binding to specific receptors in the body, which causes a variety of physiological effects, including increased heart rate and blood pressure, improved muscle strength and alertness, and narrowing of the blood vessels in the skin and intestines. It is also used as a medication to treat various medical conditions, such as anaphylaxis (a severe allergic reaction), cardiac arrest, and low blood pressure.

Glucagon is a hormone produced by the alpha cells of the pancreas. Its main function is to regulate glucose levels in the blood by stimulating the liver to convert stored glycogen into glucose, which can then be released into the bloodstream. This process helps to raise blood sugar levels when they are too low, such as during hypoglycemia.

Glucagon is a 29-amino acid polypeptide that is derived from the preproglucagon protein. It works by binding to glucagon receptors on liver cells, which triggers a series of intracellular signaling events that lead to the activation of enzymes involved in glycogen breakdown.

In addition to its role in glucose regulation, glucagon has also been shown to have other physiological effects, such as promoting lipolysis (the breakdown of fat) and inhibiting gastric acid secretion. Glucagon is often used clinically in the treatment of hypoglycemia, as well as in diagnostic tests to assess pancreatic function.

Xanthines are a type of natural alkaloids that are found in various plants, including tea leaves, cocoa beans, and mate. The most common xanthines are caffeine, theophylline, and theobromine. These compounds have stimulant effects on the central nervous system and are often used in medication to treat conditions such as asthma, bronchitis, and other respiratory issues.

Caffeine is the most widely consumed xanthine and is found in a variety of beverages like coffee, tea, and energy drinks. It works by blocking adenosine receptors in the brain, which can lead to increased alertness and reduced feelings of fatigue.

Theophylline is another xanthine that is used as a bronchodilator to treat asthma and other respiratory conditions. It works by relaxing smooth muscles in the airways, making it easier to breathe.

Theobromine is found in cocoa beans and is responsible for the stimulant effects of chocolate. While it has similar properties to caffeine and theophylline, it is less potent and has a milder effect on the body.

It's worth noting that while xanthines can have beneficial effects when used in moderation, they can also cause negative side effects such as insomnia, nervousness, and rapid heart rate if consumed in large quantities or over an extended period of time.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

"Inbred strains of rats" are genetically identical rodents that have been produced through many generations of brother-sister mating. This results in a high degree of homozygosity, where the genes at any particular locus in the genome are identical in all members of the strain.

Inbred strains of rats are widely used in biomedical research because they provide a consistent and reproducible genetic background for studying various biological phenomena, including the effects of drugs, environmental factors, and genetic mutations on health and disease. Additionally, inbred strains can be used to create genetically modified models of human diseases by introducing specific mutations into their genomes.

Some commonly used inbred strains of rats include the Wistar Kyoto (WKY), Sprague-Dawley (SD), and Fischer 344 (F344) rat strains. Each strain has its own unique genetic characteristics, making them suitable for different types of research.

Protein kinases are a group of enzymes that play a crucial role in many cellular processes by adding phosphate groups to other proteins, a process known as phosphorylation. This modification can activate or deactivate the target protein's function, thereby regulating various signaling pathways within the cell. Protein kinases are essential for numerous biological functions, including metabolism, signal transduction, cell cycle progression, and apoptosis (programmed cell death). Abnormal regulation of protein kinases has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

Alprostadil is a synthetic form of prostaglandin E1, which is a naturally occurring substance in the body. It is used medically for several purposes, including:

1. Treatment of erectile dysfunction (ED): Alprostadil can be administered directly into the penis as an injection or inserted as a suppository into the urethra to help improve blood flow and achieve an erection.
2. Prevention of closure of a patent ductus arteriosus (PDA) in premature infants: Alprostadil is used to keep the PDA open, allowing for proper blood flow between the pulmonary artery and the aorta, until surgery can be performed.
3. Treatment of peripheral arterial disease: Alprostadil can be administered intravenously to help improve blood flow in patients with peripheral arterial disease.

Alprostadil works by relaxing smooth muscle tissue in blood vessels, which increases blood flow and helps to lower blood pressure. It may also have other effects on the body, such as reducing the risk of blood clots and modulating inflammation.

It is important to note that alprostadil should only be used under the supervision of a healthcare provider, as it can have serious side effects if not used properly.

Adenylate cyclase toxin is a type of exotoxin produced by certain bacteria, including Bordetella pertussis (the causative agent of whooping cough) and Vibrio cholerae. This toxin functions by entering host cells and catalyzing the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP), leading to increased intracellular cAMP levels.

The elevated cAMP levels can disrupt various cellular processes, such as signal transduction and ion transport, resulting in a range of physiological effects that contribute to the pathogenesis of the bacterial infection. For example, in the case of Bordetella pertussis, adenylate cyclase toxin impairs the function of immune cells, allowing the bacteria to evade host defenses and establish a successful infection.

In summary, adenylate cyclase toxin is a virulence factor produced by certain pathogenic bacteria that increases intracellular cAMP levels in host cells, leading to disrupted cellular processes and contributing to bacterial pathogenesis.

Second messenger systems are a type of intracellular signaling pathway that allows cells to respond to external signals, such as hormones and neurotransmitters. When an extracellular signal binds to a specific receptor on the cell membrane, it activates a G-protein or an enzyme associated with the receptor. This activation leads to the production of a second messenger molecule inside the cell, which then propagates the signal and triggers various intracellular responses.

Examples of second messengers include cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), inositol trisphosphate (IP3), diacylglycerol (DAG), and calcium ions (Ca2+). These second messengers activate or inhibit various downstream effectors, such as protein kinases, ion channels, and gene transcription factors, leading to changes in cellular functions, such as metabolism, gene expression, cell growth, differentiation, and apoptosis.

Second messenger systems play crucial roles in many physiological processes, including sensory perception, neurotransmission, hormonal regulation, immune response, and development. Dysregulation of these systems can contribute to various diseases, such as cancer, diabetes, cardiovascular disease, and neurological disorders.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Enzyme activation refers to the process by which an enzyme becomes biologically active and capable of carrying out its specific chemical or biological reaction. This is often achieved through various post-translational modifications, such as proteolytic cleavage, phosphorylation, or addition of cofactors or prosthetic groups to the enzyme molecule. These modifications can change the conformation or structure of the enzyme, exposing or creating a binding site for the substrate and allowing the enzymatic reaction to occur.

For example, in the case of proteolytic cleavage, an inactive precursor enzyme, known as a zymogen, is cleaved into its active form by a specific protease. This is seen in enzymes such as trypsin and chymotrypsin, which are initially produced in the pancreas as inactive precursors called trypsinogen and chymotrypsinogen, respectively. Once they reach the small intestine, they are activated by enteropeptidase, a protease that cleaves a specific peptide bond, releasing the active enzyme.

Phosphorylation is another common mechanism of enzyme activation, where a phosphate group is added to a specific serine, threonine, or tyrosine residue on the enzyme by a protein kinase. This modification can alter the conformation of the enzyme and create a binding site for the substrate, allowing the enzymatic reaction to occur.

Enzyme activation is a crucial process in many biological pathways, as it allows for precise control over when and where specific reactions take place. It also provides a mechanism for regulating enzyme activity in response to various signals and stimuli, such as hormones, neurotransmitters, or changes in the intracellular environment.

Phenylisopropyladenosine (PIA) is not typically defined in the context of medical terminology, but rather it is a term used in pharmacology and biochemistry. PIA is a type of adenosine receptor agonist that specifically binds to and activates the A1 adenosine receptor.

Adenosine receptors are a type of G protein-coupled receptor (GPCR) found in various tissues throughout the body, including the brain, heart, and immune system. Activation of these receptors by agonists like PIA can have diverse effects on cellular function, such as modulating neurotransmission, reducing heart rate and contractility, and regulating inflammation.

While not a medical term per se, PIA is an important compound in the study of adenosine receptor biology and has potential therapeutic applications in various diseases, including neurological disorders, cardiovascular disease, and cancer.

2-Chloroadenosine is a synthetic, chlorinated analog of adenosine, which is a naturally occurring purine nucleoside. It acts as an antagonist at adenosine receptors and has been studied for its potential effects on the cardiovascular system, including its ability to reduce heart rate and blood pressure. It may also have anti-cancer properties and has been investigated as a potential therapeutic agent in cancer treatment. However, further research is needed to establish its safety and efficacy in clinical settings.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

Papaverine is defined as a smooth muscle relaxant and a non-narcotic alkaloid derived from the opium poppy. It works by blocking the phosphodiesterase enzyme, leading to an increase in cyclic adenosine monophosphate (cAMP) levels within the cells, which in turn results in muscle relaxation.

It is used medically for its vasodilatory effects to treat conditions such as cerebral or peripheral vascular spasms and occlusive diseases, Raynaud's phenomenon, and priapism. Papaverine can also be used as an anti-arrhythmic agent in the management of certain types of cardiac arrhythmias.

It is important to note that papaverine has a narrow therapeutic index, and its use should be closely monitored due to the potential for adverse effects such as hypotension, reflex tachycardia, and gastrointestinal disturbances.

'Dictyostelium' is a genus of social amoebae that are commonly found in soil and decaying organic matter. These microscopic organisms have a unique life cycle, starting as individual cells that feed on bacteria. When food becomes scarce, the cells undergo a developmental process where they aggregate together to form a multicellular slug-like structure called a pseudoplasmodium or grex. This grex then moves and differentiates into a fruiting body that can release spores for further reproduction.

Dictyostelium discoideum is the most well-studied species in this genus, serving as a valuable model organism for research in various fields such as cell biology, developmental biology, and evolutionary biology. The study of Dictyostelium has contributed significantly to our understanding of fundamental biological processes like chemotaxis, signal transduction, and cell differentiation.

Adenosine Triphosphate (ATP) is a high-energy molecule that stores and transports energy within cells. It is the main source of energy for most cellular processes, including muscle contraction, nerve impulse transmission, and protein synthesis. ATP is composed of a base (adenine), a sugar (ribose), and three phosphate groups. The bonds between these phosphate groups contain a significant amount of energy, which can be released when the bond between the second and third phosphate group is broken, resulting in the formation of adenosine diphosphate (ADP) and inorganic phosphate. This process is known as hydrolysis and can be catalyzed by various enzymes to drive a wide range of cellular functions. ATP can also be regenerated from ADP through various metabolic pathways, such as oxidative phosphorylation or substrate-level phosphorylation, allowing for the continuous supply of energy to cells.

Pyrrolidinones are a class of organic compounds that contain a pyrrolidinone ring, which is a five-membered ring containing four carbon atoms and one nitrogen atom. The nitrogen atom is part of an amide functional group, which consists of a carbonyl (C=O) group bonded to a nitrogen atom.

Pyrrolidinones are commonly found in various natural and synthetic compounds, including pharmaceuticals, agrochemicals, and materials. They exhibit a wide range of biological activities, such as anti-inflammatory, antiviral, and anticancer properties. Some well-known drugs that contain pyrrolidinone rings include the pain reliever tramadol, the muscle relaxant cyclobenzaprine, and the antipsychotic aripiprazole.

Pyrrolidinones can be synthesized through various chemical reactions, such as the cyclization of γ-amino acids or the reaction of α-amino acids with isocyanates. The unique structure and reactivity of pyrrolidinones make them valuable intermediates in organic synthesis and drug discovery.

Aminophylline is a medication that is used to treat and prevent respiratory symptoms such as bronchospasm, wheezing, and shortness of breath. It is a combination of theophylline and ethylenediamine, and it works by relaxing muscles in the airways and increasing the efficiency of the diaphragm, which makes breathing easier.

Aminophylline is classified as a xanthine derivative and a methylxanthine bronchodilator. It is available in various forms, including tablets, capsules, and liquid solutions, and it is typically taken by mouth two to three times a day. The medication may also be given intravenously in hospital settings for the treatment of acute respiratory distress.

Common side effects of aminophylline include nausea, vomiting, headache, and insomnia. More serious side effects can occur at higher doses and may include irregular heartbeat, seizures, and potentially life-threatening allergic reactions. It is important to follow the dosage instructions carefully and to monitor for any signs of adverse reactions while taking this medication.

Virulence factors in Bordetella pertussis, the bacterium that causes whooping cough, refer to the characteristics or components of the organism that contribute to its ability to cause disease. These virulence factors include:

1. Pertussis Toxin (PT): A protein exotoxin that inhibits the immune response and affects the nervous system, leading to the characteristic paroxysmal cough of whooping cough.
2. Adenylate Cyclase Toxin (ACT): A toxin that increases the levels of cAMP in host cells, disrupting their function and contributing to the pathogenesis of the disease.
3. Filamentous Hemagglutinin (FHA): A surface protein that allows the bacterium to adhere to host cells and evade the immune response.
4. Fimbriae: Hair-like appendages on the surface of the bacterium that facilitate adherence to host cells.
5. Pertactin (PRN): A surface protein that also contributes to adherence and is a common component of acellular pertussis vaccines.
6. Dermonecrotic Toxin: A toxin that causes localized tissue damage and necrosis, contributing to the inflammation and symptoms of whooping cough.
7. Tracheal Cytotoxin: A toxin that damages ciliated epithelial cells in the respiratory tract, impairing mucociliary clearance and increasing susceptibility to infection.

These virulence factors work together to enable Bordetella pertussis to colonize the respiratory tract, evade the host immune response, and cause the symptoms of whooping cough.

Adrenergic receptors are a type of G protein-coupled receptor that binds and responds to catecholamines, such as epinephrine (adrenaline) and norepinephrine (noradrenaline). Beta adrenergic receptors (β-adrenergic receptors) are a subtype of adrenergic receptors that include three distinct subclasses: β1, β2, and β3. These receptors are widely distributed throughout the body and play important roles in various physiological functions, including cardiovascular regulation, bronchodilation, lipolysis, and glucose metabolism.

β1-adrenergic receptors are primarily located in the heart and regulate cardiac contractility, chronotropy (heart rate), and relaxation. β2-adrenergic receptors are found in various tissues, including the lungs, vascular smooth muscle, liver, and skeletal muscle. They mediate bronchodilation, vasodilation, glycogenolysis, and lipolysis. β3-adrenergic receptors are mainly expressed in adipose tissue, where they stimulate lipolysis and thermogenesis.

Agonists of β-adrenergic receptors include catecholamines like epinephrine and norepinephrine, as well as synthetic drugs such as dobutamine (a β1-selective agonist) and albuterol (a non-selective β2-agonist). Antagonists of β-adrenergic receptors are commonly used in the treatment of various conditions, including hypertension, angina pectoris, heart failure, and asthma. Examples of β-blockers include metoprolol (a β1-selective antagonist) and carvedilol (a non-selective β-blocker with additional α1-adrenergic receptor blocking activity).

Dibutyryl cyclic guanosine monophosphate (cAMP) is a chemically modified form of the second messenger molecule, cyclic GMP (guanosine monophosphate). The addition of butyryl groups to the cyclic GMP molecule makes it more lipid-soluble and allows for easier passage through cell membranes. This compound is often used in research to activate protein kinases and study the effects of increased intracellular levels of cyclic GMP, which plays a role in various cellular processes such as smooth muscle relaxation, regulation of ion channels, and inhibition of platelet aggregation.

Thionucleotides are chemical compounds that are analogs of nucleotides, which are the building blocks of DNA and RNA. In thionucleotides, one or more of the oxygen atoms in the nucleotide's chemical structure is replaced by a sulfur atom. This modification can affect the way the thionucleotide interacts with other molecules, including enzymes that work with nucleotides and nucleic acids.

Thionucleotides are sometimes used in research to study the biochemistry of nucleic acids and their interactions with other molecules. They can also be used as inhibitors of certain enzymes, such as reverse transcriptase, which is an important target for HIV/AIDS therapy. However, thionucleotides are not normally found in natural biological systems and are not themselves components of DNA or RNA.

Propranolol is a medication that belongs to a class of drugs called beta blockers. Medically, it is defined as a non-selective beta blocker, which means it blocks the effects of both epinephrine (adrenaline) and norepinephrine (noradrenaline) on the heart and other organs. These effects include reducing heart rate, contractility, and conduction velocity, leading to decreased oxygen demand by the myocardium. Propranolol is used in the management of various conditions such as hypertension, angina pectoris, arrhythmias, essential tremor, anxiety disorders, and infants with congenital heart defects. It may also be used to prevent migraines and reduce the risk of future heart attacks. As with any medication, it should be taken under the supervision of a healthcare provider due to potential side effects and contraindications.

Dinoprostone is a prostaglandin E2 analog used in medical practice for the induction of labor and ripening of the cervix in pregnant women. It is available in various forms, including vaginal suppositories, gel, and tablets. Dinoprostone works by stimulating the contraction of uterine muscles and promoting cervical dilation, which helps in facilitating a successful delivery.

It's important to note that dinoprostone should only be administered under the supervision of a healthcare professional, as its use is associated with certain risks and side effects, including uterine hyperstimulation, fetal distress, and maternal infection. The dosage and duration of treatment are carefully monitored to minimize these risks and ensure the safety of both the mother and the baby.

Cyclic nucleotide phosphodiesterases (PDEs) are a family of enzymes that regulate intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are important second messengers involved in various cellular processes.

Type 4 phosphodiesterases (PDE4) specifically hydrolyze cAMP and play a crucial role in regulating its intracellular concentration. PDE4 is widely expressed in many tissues, including the brain, heart, lungs, and immune system. It is involved in various physiological functions such as smooth muscle relaxation, neurotransmission, and inflammation.

PDE4 inhibitors have been developed as therapeutic agents for a variety of diseases, including asthma, chronic obstructive pulmonary disease (COPD), and depression. These drugs work by increasing intracellular cAMP levels, which can lead to bronchodilation, anti-inflammatory effects, and mood regulation. However, PDE4 inhibitors may also have side effects such as nausea, vomiting, and diarrhea, which limit their clinical use.

Cyclic AMP Response Element Modulator (CREM) is a protein that functions as a transcription factor, which binds to specific DNA sequences called cis-acting elements in the promoter region of target genes and regulates their expression. The CREM protein is activated by cyclic AMP (cAMP), a second messenger molecule involved in various cellular signaling pathways.

The CREM protein contains several functional domains, including a DNA-binding domain that recognizes the cAMP response element (CRE) sequence, and a transactivation domain that interacts with other proteins to activate or repress gene transcription. The CREM protein can exist in multiple forms, including activated and repressed isoforms, which are generated by alternative splicing of its pre-mRNA.

The CREM protein plays important roles in various biological processes, such as neuronal development, circadian rhythm regulation, and immune response. Dysregulation of CREM has been implicated in several diseases, including cancer, neurodegenerative disorders, and metabolic disorders.

Vasoactive Intestinal Peptide (VIP) is a 28-amino acid polypeptide hormone that has potent vasodilatory, secretory, and neurotransmitter effects. It is widely distributed throughout the body, including in the gastrointestinal tract, where it is synthesized and released by nerve cells (neurons) in the intestinal mucosa. VIP plays a crucial role in regulating various physiological functions such as intestinal secretion, motility, and blood flow. It also has immunomodulatory effects and may play a role in neuroprotection. High levels of VIP are found in the brain, where it acts as a neurotransmitter or neuromodulator and is involved in various cognitive functions such as learning, memory, and social behavior.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

I must clarify that the term "Guinea Pigs" is not typically used in medical definitions. However, in colloquial or informal language, it may refer to people who are used as the first to try out a new medical treatment or drug. This is known as being a "test subject" or "in a clinical trial."

In the field of scientific research, particularly in studies involving animals, guinea pigs are small rodents that are often used as experimental subjects due to their size, cost-effectiveness, and ease of handling. They are not actually pigs from Guinea, despite their name's origins being unclear. However, they do not exactly fit the description of being used in human medical experiments.

Adrenergic beta-agonists are a class of medications that bind to and activate beta-adrenergic receptors, which are found in various tissues throughout the body. These receptors are part of the sympathetic nervous system and mediate the effects of the neurotransmitter norepinephrine (also called noradrenaline) and the hormone epinephrine (also called adrenaline).

When beta-agonists bind to these receptors, they stimulate a range of physiological responses, including relaxation of smooth muscle in the airways, increased heart rate and contractility, and increased metabolic rate. As a result, adrenergic beta-agonists are often used to treat conditions such as asthma, chronic obstructive pulmonary disease (COPD), and bronchitis, as they can help to dilate the airways and improve breathing.

There are several different types of beta-agonists, including short-acting and long-acting formulations. Short-acting beta-agonists (SABAs) are typically used for quick relief of symptoms, while long-acting beta-agonists (LABAs) are used for more sustained symptom control. Examples of adrenergic beta-agonists include albuterol (also known as salbutamol), terbutaline, formoterol, and salmeterol.

It's worth noting that while adrenergic beta-agonists can be very effective in treating respiratory conditions, they can also have side effects, particularly if used in high doses or for prolonged periods of time. These may include tremors, anxiety, palpitations, and increased blood pressure. As with any medication, it's important to use adrenergic beta-agonists only as directed by a healthcare professional.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Pertussis toxin is an exotoxin produced by the bacterium Bordetella pertussis, which is responsible for causing whooping cough in humans. This toxin has several effects on the host organism, including:

1. Adenylyl cyclase activation: Pertussis toxin enters the host cell and modifies a specific G protein (Gαi), leading to the continuous activation of adenylyl cyclase. This results in increased levels of intracellular cAMP, which disrupts various cellular processes.
2. Inhibition of immune response: Pertussis toxin impairs the host's immune response by inhibiting the migration and function of immune cells like neutrophils and macrophages. It also interferes with antigen presentation and T-cell activation, making it difficult for the body to clear the infection.
3. Increased inflammation: The continuous activation of adenylyl cyclase by pertussis toxin leads to increased production of proinflammatory cytokines, contributing to the severe coughing fits and other symptoms associated with whooping cough.

Pertussis toxin is an essential virulence factor for Bordetella pertussis, and its effects contribute significantly to the pathogenesis of whooping cough. Vaccination against pertussis includes inactivated or genetically detoxified forms of pertussis toxin, which provide immunity without causing disease symptoms.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Inositol phosphates are a family of molecules that consist of an inositol ring, which is a six-carbon heterocyclic compound, linked to one or more phosphate groups. These molecules play important roles as intracellular signaling intermediates and are involved in various cellular processes such as cell growth, differentiation, and metabolism.

Inositol hexakisphosphate (IP6), also known as phytic acid, is a form of inositol phosphate that is found in plant-based foods. IP6 has the ability to bind to minerals such as calcium, magnesium, and iron, which can reduce their bioavailability in the body.

Inositol phosphates have been implicated in several diseases, including cancer, diabetes, and neurodegenerative disorders. For example, altered levels of certain inositol phosphates have been observed in cancer cells, suggesting that they may play a role in tumor growth and progression. Additionally, mutations in enzymes involved in the metabolism of inositol phosphates have been associated with several genetic diseases.

Carbachol is a cholinergic agonist, which means it stimulates the parasympathetic nervous system by mimicking the action of acetylcholine, a neurotransmitter that is involved in transmitting signals between nerves and muscles. Carbachol binds to both muscarinic and nicotinic receptors, but its effects are more pronounced on muscarinic receptors.

Carbachol is used in medical treatments to produce miosis (pupil constriction), lower intraocular pressure, and stimulate gastrointestinal motility. It can also be used as a diagnostic tool to test for certain conditions such as Hirschsprung's disease.

Like any medication, carbachol can have side effects, including sweating, salivation, nausea, vomiting, diarrhea, bradycardia (slow heart rate), and bronchoconstriction (narrowing of the airways in the lungs). It should be used with caution and under the supervision of a healthcare professional.

Adrenergic receptors are a type of G protein-coupled receptor that bind and respond to catecholamines, which include the neurotransmitters norepinephrine (noradrenaline) and epinephrine (adrenaline). These receptors play a crucial role in the body's "fight or flight" response and are involved in regulating various physiological functions such as heart rate, blood pressure, respiration, and metabolism.

There are nine different subtypes of adrenergic receptors, which are classified into two main groups based on their pharmacological properties: alpha (α) and beta (β) receptors. Alpha receptors are further divided into two subgroups, α1 and α2, while beta receptors are divided into three subgroups, β1, β2, and β3. Each subtype has a unique distribution in the body and mediates distinct physiological responses.

Activation of adrenergic receptors occurs when catecholamines bind to their specific binding sites on the receptor protein. This binding triggers a cascade of intracellular signaling events that ultimately lead to changes in cell function. Different subtypes of adrenergic receptors activate different G proteins and downstream signaling pathways, resulting in diverse physiological responses.

In summary, adrenergic receptors are a class of G protein-coupled receptors that bind catecholamines and mediate various physiological functions. Understanding the function and regulation of these receptors is essential for developing therapeutic strategies to treat a range of medical conditions, including hypertension, heart failure, asthma, and anxiety disorders.

Norepinephrine, also known as noradrenaline, is a neurotransmitter and a hormone that is primarily produced in the adrenal glands and is released into the bloodstream in response to stress or physical activity. It plays a crucial role in the "fight-or-flight" response by preparing the body for action through increasing heart rate, blood pressure, respiratory rate, and glucose availability.

As a neurotransmitter, norepinephrine is involved in regulating various functions of the nervous system, including attention, perception, motivation, and arousal. It also plays a role in modulating pain perception and responding to stressful or emotional situations.

In medical settings, norepinephrine is used as a vasopressor medication to treat hypotension (low blood pressure) that can occur during septic shock, anesthesia, or other critical illnesses. It works by constricting blood vessels and increasing heart rate, which helps to improve blood pressure and perfusion of vital organs.

Cycloheximide is an antibiotic that is primarily used in laboratory settings to inhibit protein synthesis in eukaryotic cells. It is derived from the actinobacteria species Streptomyces griseus. In medical terms, it is not used as a therapeutic drug in humans due to its significant side effects, including liver toxicity and potential neurotoxicity. However, it remains a valuable tool in research for studying protein function and cellular processes.

The antibiotic works by binding to the 60S subunit of the ribosome, thereby preventing the transfer RNA (tRNA) from delivering amino acids to the growing polypeptide chain during translation. This inhibition of protein synthesis can be lethal to cells, making cycloheximide a useful tool in studying cellular responses to protein depletion or misregulation.

In summary, while cycloheximide has significant research applications due to its ability to inhibit protein synthesis in eukaryotic cells, it is not used as a therapeutic drug in humans because of its toxic side effects.

Histamine is defined as a biogenic amine that is widely distributed throughout the body and is involved in various physiological functions. It is derived primarily from the amino acid histidine by the action of histidine decarboxylase. Histamine is stored in granules (along with heparin and proteases) within mast cells and basophils, and is released upon stimulation or degranulation of these cells.

Once released into the tissues and circulation, histamine exerts a wide range of pharmacological actions through its interaction with four types of G protein-coupled receptors (H1, H2, H3, and H4 receptors). Histamine's effects are diverse and include modulation of immune responses, contraction and relaxation of smooth muscle, increased vascular permeability, stimulation of gastric acid secretion, and regulation of neurotransmission.

Histamine is also a potent mediator of allergic reactions and inflammation, causing symptoms such as itching, sneezing, runny nose, and wheezing. Antihistamines are commonly used to block the actions of histamine at H1 receptors, providing relief from these symptoms.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Diterpenes are a class of naturally occurring compounds that are composed of four isoprene units, which is a type of hydrocarbon. They are synthesized by a wide variety of plants and animals, and are found in many different types of organisms, including fungi, insects, and marine organisms.

Diterpenes have a variety of biological activities and are used in medicine for their therapeutic effects. Some diterpenes have anti-inflammatory, antimicrobial, and antiviral properties, and are used to treat a range of conditions, including respiratory infections, skin disorders, and cancer.

Diterpenes can be further classified into different subgroups based on their chemical structure and biological activity. Some examples of diterpenes include the phytocannabinoids found in cannabis plants, such as THC and CBD, and the paclitaxel, a diterpene found in the bark of the Pacific yew tree that is used to treat cancer.

It's important to note that while some diterpenes have therapeutic potential, others may be toxic or have adverse effects, so it is essential to use them under the guidance and supervision of a healthcare professional.

Glucose is a simple monosaccharide (or single sugar) that serves as the primary source of energy for living organisms. It's a fundamental molecule in biology, often referred to as "dextrose" or "grape sugar." Glucose has the molecular formula C6H12O6 and is vital to the functioning of cells, especially those in the brain and nervous system.

In the body, glucose is derived from the digestion of carbohydrates in food, and it's transported around the body via the bloodstream to cells where it can be used for energy. Cells convert glucose into a usable form through a process called cellular respiration, which involves a series of metabolic reactions that generate adenosine triphosphate (ATP)—the main currency of energy in cells.

Glucose is also stored in the liver and muscles as glycogen, a polysaccharide (multiple sugar) that can be broken down back into glucose when needed for energy between meals or during physical activity. Maintaining appropriate blood glucose levels is crucial for overall health, and imbalances can lead to conditions such as diabetes mellitus.

Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.

2,3'-Cyclic-nucleotide phosphodiesterases (PDEs) are a subclass of enzymes that belong to the family of phosphodiesterases. These enzymes are responsible for the hydrolysis of 2,3'-cyclic nucleotides, which are cyclic forms of nucleotides that act as second messengers in various cellular signaling pathways.

The two primary types of 2,3'-cyclic nucleotides are 2',3'-cGMP and 2',3'-cAMP, which are produced by the action of certain enzymes on their respective precursors, guanosine triphosphate (GTP) and adenosine triphosphate (ATP). These cyclic nucleotides play important roles in regulating various cellular processes, including metabolism, gene expression, and ion channel activity.

2,3'-Cyclic-nucleotide phosphodiesterases catalyze the hydrolysis of these cyclic nucleotides to their corresponding 5'-monophosphates, thereby terminating their signaling activity. There are several isoforms of 2,3'-cyclic-nucleotide PDEs that have been identified, each with distinct substrate specificities and regulatory properties.

Dysregulation of 2,3'-cyclic-nucleotide PDE activity has been implicated in various diseases, including cancer, cardiovascular disease, and neurological disorders. Therefore, these enzymes have emerged as important targets for the development of therapeutic agents that can modulate their activity and restore normal cellular function.

Enzyme induction is a process by which the activity or expression of an enzyme is increased in response to some stimulus, such as a drug, hormone, or other environmental factor. This can occur through several mechanisms, including increasing the transcription of the enzyme's gene, stabilizing the mRNA that encodes the enzyme, or increasing the translation of the mRNA into protein.

In some cases, enzyme induction can be a beneficial process, such as when it helps the body to metabolize and clear drugs more quickly. However, in other cases, enzyme induction can have negative consequences, such as when it leads to the increased metabolism of important endogenous compounds or the activation of harmful procarcinogens.

Enzyme induction is an important concept in pharmacology and toxicology, as it can affect the efficacy and safety of drugs and other xenobiotics. It is also relevant to the study of drug interactions, as the induction of one enzyme by a drug can lead to altered metabolism and effects of another drug that is metabolized by the same enzyme.

Prostaglandins are naturally occurring, lipid-derived hormones that play various important roles in the human body. They are produced in nearly every tissue in response to injury or infection, and they have diverse effects depending on the site of release and the type of prostaglandin. Some of their functions include:

1. Regulation of inflammation: Prostaglandins contribute to the inflammatory response by increasing vasodilation, promoting fluid accumulation, and sensitizing pain receptors, which can lead to symptoms such as redness, heat, swelling, and pain.
2. Modulation of gastrointestinal functions: Prostaglandins protect the stomach lining from acid secretion and promote mucus production, maintaining the integrity of the gastric mucosa. They also regulate intestinal motility and secretion.
3. Control of renal function: Prostaglandins help regulate blood flow to the kidneys, maintain sodium balance, and control renin release, which affects blood pressure and fluid balance.
4. Regulation of smooth muscle contraction: Prostaglandins can cause both relaxation and contraction of smooth muscles in various tissues, such as the uterus, bronchioles, and vascular system.
5. Modulation of platelet aggregation: Some prostaglandins inhibit platelet aggregation, preventing blood clots from forming too quickly or becoming too large.
6. Reproductive system regulation: Prostaglandins are involved in the menstrual cycle, ovulation, and labor induction by promoting uterine contractions.
7. Neurotransmission: Prostaglandins can modulate neurotransmitter release and neuronal excitability, affecting pain perception, mood, and cognition.

Prostaglandins exert their effects through specific G protein-coupled receptors (GPCRs) found on the surface of target cells. There are several distinct types of prostaglandins (PGs), including PGD2, PGE2, PGF2α, PGI2 (prostacyclin), and thromboxane A2 (TXA2). Each type has unique functions and acts through specific receptors. Prostaglandins are synthesized from arachidonic acid, a polyunsaturated fatty acid derived from membrane phospholipids, by the action of cyclooxygenase (COX) enzymes. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen, inhibit COX activity, reducing prostaglandin synthesis and providing analgesic, anti-inflammatory, and antipyretic effects.

Phosphorylases are enzymes that catalyze the phosphorolytic cleavage of a bond, often a glycosidic bond, in a carbohydrate molecule, releasing a sugar moiety and a phosphate group. This reaction is important in metabolic pathways such as glycogenolysis, where glycogen is broken down into glucose-1-phosphate by the action of glycogen phosphorylase. The resulting glucose-1-phosphate can then be further metabolized to produce energy. Phosphorylases are widely found in nature and play a crucial role in various biological processes, including energy metabolism and signal transduction.

Adrenocorticotropic Hormone (ACTH) is a hormone produced and released by the anterior pituitary gland, a small endocrine gland located at the base of the brain. ACTH plays a crucial role in the regulation of the body's stress response and has significant effects on various physiological processes.

The primary function of ACTH is to stimulate the adrenal glands, which are triangular-shaped glands situated on top of the kidneys. The adrenal glands consist of two parts: the outer cortex and the inner medulla. ACTH specifically targets the adrenal cortex, where it binds to specific receptors and initiates a series of biochemical reactions leading to the production and release of steroid hormones, primarily cortisol (a glucocorticoid) and aldosterone (a mineralocorticoid).

Cortisol is involved in various metabolic processes, such as regulating blood sugar levels, modulating the immune response, and helping the body respond to stress. Aldosterone plays a vital role in maintaining electrolyte and fluid balance by promoting sodium reabsorption and potassium excretion in the kidneys.

ACTH release is controlled by the hypothalamus, another part of the brain, which produces corticotropin-releasing hormone (CRH). CRH stimulates the anterior pituitary gland to secrete ACTH, which in turn triggers cortisol production in the adrenal glands. This complex feedback system helps maintain homeostasis and ensures that appropriate amounts of cortisol are released in response to various physiological and psychological stressors.

Disorders related to ACTH can lead to hormonal imbalances, resulting in conditions such as Cushing's syndrome (excessive cortisol production) or Addison's disease (insufficient cortisol production). Proper diagnosis and management of these disorders typically involve assessing the function of the hypothalamic-pituitary-adrenal axis and addressing any underlying issues affecting ACTH secretion.

Promoter regions in genetics refer to specific DNA sequences located near the transcription start site of a gene. They serve as binding sites for RNA polymerase and various transcription factors that regulate the initiation of gene transcription. These regulatory elements help control the rate of transcription and, therefore, the level of gene expression. Promoter regions can be composed of different types of sequences, such as the TATA box and CAAT box, and their organization and composition can vary between different genes and species.

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

Dideoxyadenosine (ddA) is a type of synthetic nucleoside analogue, which is a synthetic compound that resembles one of the building blocks of DNA or RNA. More specifically, ddA resembles adenosine, one of the four nucleosides that make up DNA.

Dideoxyadenosine is used in research and medicine as an inhibitor of reverse transcriptase, an enzyme that is produced by retroviruses such as HIV. By blocking the action of this enzyme, ddA can prevent the virus from replicating and infecting new cells.

Dideoxyadenosine is often used in combination with other antiretroviral drugs as part of highly active antiretroviral therapy (HAART) to treat HIV infection and AIDS. It is usually administered as a prodrug, such as didanosine or ddI, which is converted to the active form of the drug in the body.

It's important to note that Dideoxyadenosine itself is not used directly as a medication but its derivatives like Didanosine are used in treatment.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Insulin is a hormone produced by the beta cells of the pancreatic islets, primarily in response to elevated levels of glucose in the circulating blood. It plays a crucial role in regulating blood glucose levels and facilitating the uptake and utilization of glucose by peripheral tissues, such as muscle and adipose tissue, for energy production and storage. Insulin also inhibits glucose production in the liver and promotes the storage of excess glucose as glycogen or triglycerides.

Deficiency in insulin secretion or action leads to impaired glucose regulation and can result in conditions such as diabetes mellitus, characterized by chronic hyperglycemia and associated complications. Exogenous insulin is used as a replacement therapy in individuals with diabetes to help manage their blood glucose levels and prevent long-term complications.

Purinergic receptors are a type of cell surface receptor that bind and respond to purines and pyrimidines, which are nucleotides and nucleosides. These receptors are involved in various physiological processes, including neurotransmission, muscle contraction, and inflammation. There are two main types of purinergic receptors: P1 receptors, which are activated by adenosine, and P2 receptors, which are activated by ATP and other nucleotides.

P2 receptors are further divided into two subtypes: P2X and P2Y. P2X receptors are ionotropic receptors that form cation channels upon activation, allowing the flow of ions such as calcium and sodium into the cell. P2Y receptors, on the other hand, are metabotropic receptors that activate G proteins upon activation, leading to the activation or inhibition of various intracellular signaling pathways.

Purinergic receptors have been found to play a role in many diseases and conditions, including neurological disorders, cardiovascular disease, and cancer. They are also being studied as potential targets for drug development.

Tritium is not a medical term, but it is a term used in the field of nuclear physics and chemistry. Tritium (symbol: T or 3H) is a radioactive isotope of hydrogen with two neutrons and one proton in its nucleus. It is also known as heavy hydrogen or superheavy hydrogen.

Tritium has a half-life of about 12.3 years, which means that it decays by emitting a low-energy beta particle (an electron) to become helium-3. Due to its radioactive nature and relatively short half-life, tritium is used in various applications, including nuclear weapons, fusion reactors, luminous paints, and medical research.

In the context of medicine, tritium may be used as a radioactive tracer in some scientific studies or medical research, but it is not a term commonly used to describe a medical condition or treatment.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Parathyroid hormone (PTH) is a polypeptide hormone that plays a crucial role in the regulation of calcium and phosphate levels in the body. It is produced and secreted by the parathyroid glands, which are four small endocrine glands located on the back surface of the thyroid gland.

The primary function of PTH is to maintain normal calcium levels in the blood by increasing calcium absorption from the gut, mobilizing calcium from bones, and decreasing calcium excretion by the kidneys. PTH also increases phosphate excretion by the kidneys, which helps to lower serum phosphate levels.

In addition to its role in calcium and phosphate homeostasis, PTH has been shown to have anabolic effects on bone tissue, stimulating bone formation and preventing bone loss. However, chronic elevations in PTH levels can lead to excessive bone resorption and osteoporosis.

Overall, Parathyroid Hormone is a critical hormone that helps maintain mineral homeostasis and supports healthy bone metabolism.

Inosine triphosphate (ITP) is not a medical condition, but rather a biochemical compound that plays a role in the body's energy metabolism and nucleic acid synthesis. It is an ester of inosine and triphosphoric acid. ITP can be produced from adenosine triphosphate (ATP) by the action of enzymes such as adenylate kinase or nucleoside diphosphate kinase, and it can also be degraded back to inosine monophosphate (IMP) by the enzyme ITP pyrophosphatase.

In certain disease states, such as some types of anemia, there may be an accumulation of ITP due to impaired breakdown. However, ITP is not typically used as a diagnostic or clinical marker in these conditions.

Drug synergism is a pharmacological concept that refers to the interaction between two or more drugs, where the combined effect of the drugs is greater than the sum of their individual effects. This means that when these drugs are administered together, they produce an enhanced therapeutic response compared to when they are given separately.

Drug synergism can occur through various mechanisms, such as:

1. Pharmacodynamic synergism - When two or more drugs interact with the same target site in the body and enhance each other's effects.
2. Pharmacokinetic synergism - When one drug affects the metabolism, absorption, distribution, or excretion of another drug, leading to an increased concentration of the second drug in the body and enhanced therapeutic effect.
3. Physiochemical synergism - When two drugs interact physically, such as when one drug enhances the solubility or permeability of another drug, leading to improved absorption and bioavailability.

It is important to note that while drug synergism can result in enhanced therapeutic effects, it can also increase the risk of adverse reactions and toxicity. Therefore, healthcare providers must carefully consider the potential benefits and risks when prescribing combinations of drugs with known or potential synergistic effects.

Adenosine diphosphate (ADP) is a chemical compound that plays a crucial role in energy transfer within cells. It is a nucleotide, which consists of a adenosine molecule (a sugar molecule called ribose attached to a nitrogenous base called adenine) and two phosphate groups.

In the cell, ADP functions as an intermediate in the conversion of energy from one form to another. When a high-energy phosphate bond in ADP is broken, energy is released and ADP is converted to adenosine triphosphate (ATP), which serves as the main energy currency of the cell. Conversely, when ATP donates a phosphate group to another molecule, it is converted back to ADP, releasing energy for the cell to use.

ADP also plays a role in blood clotting and other physiological processes. In the coagulation cascade, ADP released from damaged red blood cells can help activate platelets and initiate the formation of a blood clot.

Cyclic nucleotide phosphodiesterases (PDEs) are a family of enzymes that regulate intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are important second messengers involved in various cellular processes.

Type 3 PDEs, also known as PDE3, are a subtype of this enzyme family that specifically hydrolyze cAMP and cGMP. They are widely expressed in various tissues, including the heart, vascular smooth muscle, platelets, and adipose tissue.

PDE3 plays a crucial role in regulating cardiovascular function, lipolysis, and insulin sensitivity. Inhibition of PDE3 has been shown to have positive inotropic and vasodilatory effects, making it a potential therapeutic target for the treatment of heart failure and pulmonary hypertension. Additionally, PDE3 inhibitors have been used as antiplatelet agents to prevent thrombosis.

There are two isoforms of PDE3, PDE3A and PDE3B, which differ in their tissue distribution and regulatory mechanisms. PDE3A is primarily expressed in the heart and vascular smooth muscle, while PDE3B is found in adipose tissue and insulin-sensitive cells.

Overall, the regulation of intracellular cAMP and cGMP levels by PDE3 plays a critical role in maintaining cardiovascular function, metabolism, and hemostasis.

Dactinomycin is an antineoplastic antibiotic, which means it is used to treat cancer. It is specifically used to treat certain types of testicular cancer, Wilms' tumor (a type of kidney cancer that occurs in children), and some gestational trophoblastic tumors (a type of tumor that can develop in the uterus after pregnancy). Dactinomycin works by interfering with the DNA in cancer cells, which prevents them from dividing and growing. It is often used in combination with other chemotherapy drugs as part of a treatment regimen.

Dactinomycin is administered intravenously (through an IV) and its use is usually limited to hospitals or specialized cancer treatment centers due to the need for careful monitoring during administration. Common side effects include nausea, vomiting, and hair loss. More serious side effects can include bone marrow suppression, which can lead to an increased risk of infection, and tissue damage at the site where the drug is injected. Dactinomycin can also cause severe allergic reactions in some people.

It's important to note that dactinomycin should only be used under the supervision of a qualified healthcare professional, as its use requires careful monitoring and management of potential side effects.

Tetradecanoylphorbol acetate (TPA) is defined as a pharmacological agent that is a derivative of the phorbol ester family. It is a potent tumor promoter and activator of protein kinase C (PKC), a group of enzymes that play a role in various cellular processes such as signal transduction, proliferation, and differentiation. TPA has been widely used in research to study PKC-mediated signaling pathways and its role in cancer development and progression. It is also used in topical treatments for skin conditions such as psoriasis.

Calcimycin is a ionophore compound that is produced by the bacterium Streptomyces chartreusensis. It is also known as Calcineurin A inhibitor because it can bind to and inhibit the activity of calcineurin, a protein phosphatase. In medical research, calcimycin is often used to study calcium signaling in cells.
It has been also used in laboratory studies for its antiproliferative and pro-apoptotic effects on certain types of cancer cells. However, it is not approved for use as a drug in humans.

Nucleotide deaminases are a group of enzymes that catalyze the removal of an amino group (-NH2) from nucleotides, which are the building blocks of DNA and RNA. Specifically, these enzymes convert cytidine or adenosine to uridine or inosine, respectively, by removing an amino group from the corresponding nitrogenous base (cytosine or adenine).

There are several types of nucleotide deaminases that differ in their substrate specificity and cellular localization. For example, some enzymes deaminate DNA or RNA directly, while others act on free nucleotides or nucleosides. Nucleotide deaminases play important roles in various biological processes, including the regulation of gene expression, immune response, and DNA repair.

Abnormal activity or mutations in nucleotide deaminases have been associated with several human diseases, such as cancer, autoimmune disorders, and viral infections. Therefore, understanding the function and regulation of these enzymes is crucial for developing new therapeutic strategies to treat these conditions.

Purinergic P1 receptors are a type of G-protein coupled receptor that bind to nucleotides such as adenosine. These receptors are involved in a variety of physiological processes, including modulation of neurotransmitter release, cardiovascular function, and immune response. There are four subtypes of P1 receptors (A1, A2A, A2B, and A3) that have different signaling pathways and functions. Activation of these receptors can lead to a variety of cellular responses, including inhibition or stimulation of adenylyl cyclase activity, changes in intracellular calcium levels, and activation of various protein kinases. They play important roles in the central nervous system, cardiovascular system, respiratory system, gastrointestinal system, and immune system.

Histamine H2 receptors are a type of G protein-coupled receptor that are widely distributed throughout the body, including in the stomach, heart, and brain. They are activated by the neurotransmitter histamine, which is released by mast cells in response to an allergen or injury. When histamine binds to H2 receptors, it triggers a variety of physiological responses, such as increasing gastric acid secretion, regulating heart rate and contractility, and modulating neurotransmitter release in the brain. Histamine H2 receptor antagonists, also known as H2 blockers, are commonly used to treat gastroesophageal reflux disease (GERD) and peptic ulcers by reducing gastric acid production. Examples of H2 blockers include ranitidine (Zantac), famotidine (Pepcid), and cimetidine (Tagamet).

Vasopressin, also known as antidiuretic hormone (ADH), is a hormone that helps regulate water balance in the body. It is produced by the hypothalamus and stored in the posterior pituitary gland. When the body is dehydrated or experiencing low blood pressure, vasopressin is released into the bloodstream, where it causes the kidneys to decrease the amount of urine they produce and helps to constrict blood vessels, thereby increasing blood pressure. This helps to maintain adequate fluid volume in the body and ensure that vital organs receive an adequate supply of oxygen-rich blood. In addition to its role in water balance and blood pressure regulation, vasopressin also plays a role in social behaviors such as pair bonding and trust.

Phosphates, in a medical context, refer to the salts or esters of phosphoric acid. Phosphates play crucial roles in various biological processes within the human body. They are essential components of bones and teeth, where they combine with calcium to form hydroxyapatite crystals. Phosphates also participate in energy transfer reactions as phosphate groups attached to adenosine diphosphate (ADP) and adenosine triphosphate (ATP). Additionally, they contribute to buffer systems that help maintain normal pH levels in the body.

Abnormal levels of phosphates in the blood can indicate certain medical conditions. High phosphate levels (hyperphosphatemia) may be associated with kidney dysfunction, hyperparathyroidism, or excessive intake of phosphate-containing products. Low phosphate levels (hypophosphatemia) might result from malnutrition, vitamin D deficiency, or certain diseases affecting the small intestine or kidneys. Both hypophosphatemia and hyperphosphatemia can have significant impacts on various organ systems and may require medical intervention.

Phosphatidylinositols (PIs) are a type of phospholipid that are abundant in the cell membrane. They contain a glycerol backbone, two fatty acid chains, and a head group consisting of myo-inositol, a cyclic sugar molecule, linked to a phosphate group.

Phosphatidylinositols can be phosphorylated at one or more of the hydroxyl groups on the inositol ring, forming various phosphoinositides (PtdInsPs) with different functions. These signaling molecules play crucial roles in regulating cellular processes such as membrane trafficking, cytoskeletal organization, and signal transduction pathways that control cell growth, differentiation, and survival.

Phosphatidylinositol 4,5-bisphosphate (PIP2) is a prominent phosphoinositide involved in the regulation of ion channels, enzymes, and cytoskeletal proteins. Upon activation of certain receptors, PIP2 can be cleaved by the enzyme phospholipase C into diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (InsP3), which act as second messengers to trigger downstream signaling events.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Secretin is a hormone that is produced and released by the S cells in the duodenum, which is the first part of the small intestine. It is released in response to the presence of acidic chyme (partially digested food) entering the duodenum from the stomach. Secretin stimulates the pancreas to produce bicarbonate-rich alkaline secretions, which help neutralize the acidity of the chyme and create an optimal environment for enzymatic digestion in the small intestine.

Additionally, secretin also promotes the production of watery fluids from the liver, which aids in the digestion process. Overall, secretin plays a crucial role in maintaining the pH balance and facilitating proper nutrient absorption in the gastrointestinal tract.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Muscle relaxation, in a medical context, refers to the process of reducing tension and promoting relaxation in the skeletal muscles. This can be achieved through various techniques, including progressive muscle relaxation (PMR), where individuals consciously tense and then release specific muscle groups in a systematic manner.

PMR has been shown to help reduce anxiety, stress, and muscle tightness, and improve overall well-being. It is often used as a complementary therapy in conjunction with other treatments for conditions such as chronic pain, headaches, and insomnia.

Additionally, muscle relaxation can also be facilitated through pharmacological interventions, such as the use of muscle relaxant medications. These drugs work by inhibiting the transmission of signals between nerves and muscles, leading to a reduction in muscle tone and spasticity. They are commonly used to treat conditions such as multiple sclerosis, cerebral palsy, and spinal cord injuries.

Protein Kinase C (PKC) is a family of serine-threonine kinases that play crucial roles in various cellular signaling pathways. These enzymes are activated by second messengers such as diacylglycerol (DAG) and calcium ions (Ca2+), which result from the activation of cell surface receptors like G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs).

Once activated, PKC proteins phosphorylate downstream target proteins, thereby modulating their activities. This regulation is involved in numerous cellular processes, including cell growth, differentiation, apoptosis, and membrane trafficking. There are at least 10 isoforms of PKC, classified into three subfamilies based on their second messenger requirements and structural features: conventional (cPKC; α, βI, βII, and γ), novel (nPKC; δ, ε, η, and θ), and atypical (aPKC; ζ and ι/λ). Dysregulation of PKC signaling has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

Adenine nucleotides are molecules that consist of a nitrogenous base called adenine, which is linked to a sugar molecule (ribose in the case of adenosine monophosphate or AMP, and deoxyribose in the case of adenosine diphosphate or ADP and adenosine triphosphate or ATP) and one, two, or three phosphate groups. These molecules play a crucial role in energy transfer and metabolism within cells.

AMP contains one phosphate group, while ADP contains two phosphate groups, and ATP contains three phosphate groups. When a phosphate group is removed from ATP, energy is released, which can be used to power various cellular processes such as muscle contraction, nerve impulse transmission, and protein synthesis. The reverse reaction, in which a phosphate group is added back to ADP or AMP to form ATP, requires energy input and often involves the breakdown of nutrients such as glucose or fatty acids.

In addition to their role in energy metabolism, adenine nucleotides also serve as precursors for other important molecules, including DNA and RNA, coenzymes, and signaling molecules.

'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.

Metiamide is not generally considered a medical term, but it is a medication that has been used in the past. Medically, metiamide is defined as a synthetic histamine H2-receptor antagonist, which means it blocks the action of histamine at the H2 receptors in the stomach. This effect reduces gastric acid secretion and can be useful in treating gastroesophageal reflux disease (GERD), peptic ulcers, and other conditions associated with excessive stomach acid production.

However, metiamide has largely been replaced by other H2 blockers like cimetidine, ranitidine, and famotidine due to its association with a rare but serious side effect called agranulocytosis, which is a severe decrease in white blood cell count that can increase the risk of infections.

Butyrates are a type of fatty acid, specifically called short-chain fatty acids (SCFAs), that are produced in the gut through the fermentation of dietary fiber by gut bacteria. The name "butyrate" comes from the Latin word for butter, "butyrum," as butyrate was first isolated from butter.

Butyrates have several important functions in the body. They serve as a primary energy source for colonic cells and play a role in maintaining the health and integrity of the intestinal lining. Additionally, butyrates have been shown to have anti-inflammatory effects, regulate gene expression, and may even help prevent certain types of cancer.

In medical contexts, butyrate supplements are sometimes used to treat conditions such as ulcerative colitis, a type of inflammatory bowel disease (IBD), due to their anti-inflammatory properties and ability to promote gut health. However, more research is needed to fully understand the potential therapeutic uses of butyrates and their long-term effects on human health.

Catecholamines are a group of hormones and neurotransmitters that are derived from the amino acid tyrosine. The most well-known catecholamines are dopamine, norepinephrine (also known as noradrenaline), and epinephrine (also known as adrenaline). These hormones are produced by the adrenal glands and are released into the bloodstream in response to stress. They play important roles in the "fight or flight" response, increasing heart rate, blood pressure, and alertness. In addition to their role as hormones, catecholamines also function as neurotransmitters, transmitting signals in the nervous system. Disorders of catecholamine regulation can lead to a variety of medical conditions, including hypertension, mood disorders, and neurological disorders.

Magnesium is an essential mineral that plays a crucial role in various biological processes in the human body. It is the fourth most abundant cation in the body and is involved in over 300 enzymatic reactions, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Magnesium also contributes to the structural development of bones and teeth.

In medical terms, magnesium deficiency can lead to several health issues, such as muscle cramps, weakness, heart arrhythmias, and seizures. On the other hand, excessive magnesium levels can cause symptoms like diarrhea, nausea, and muscle weakness. Magnesium supplements or magnesium-rich foods are often recommended to maintain optimal magnesium levels in the body.

Some common dietary sources of magnesium include leafy green vegetables, nuts, seeds, legumes, whole grains, and dairy products. Magnesium is also available in various forms as a dietary supplement, including magnesium oxide, magnesium citrate, magnesium chloride, and magnesium glycinate.

I'm sorry for any confusion, but "Purinones" is not a recognized term in medical terminology. It seems there might be a spelling mistake or a misunderstanding of the term. If you meant "purines," I can provide a definition for that. Purines are heterocyclic aromatic organic compounds that form the basis of several important biomolecules, such as nucleotides and their derivatives found in DNA and RNA. If you had something different in mind, please provide clarification so I can give you an accurate and helpful response.

Serotonin, also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter that is found primarily in the gastrointestinal (GI) tract, blood platelets, and the central nervous system (CNS) of humans and other animals. It is produced by the conversion of the amino acid tryptophan to 5-hydroxytryptophan (5-HTP), and then to serotonin.

In the CNS, serotonin plays a role in regulating mood, appetite, sleep, memory, learning, and behavior, among other functions. It also acts as a vasoconstrictor, helping to regulate blood flow and blood pressure. In the GI tract, it is involved in peristalsis, the contraction and relaxation of muscles that moves food through the digestive system.

Serotonin is synthesized and stored in serotonergic neurons, which are nerve cells that use serotonin as their primary neurotransmitter. These neurons are found throughout the brain and spinal cord, and they communicate with other neurons by releasing serotonin into the synapse, the small gap between two neurons.

Abnormal levels of serotonin have been linked to a variety of disorders, including depression, anxiety, schizophrenia, and migraines. Medications that affect serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs), are commonly used to treat these conditions.

Smooth muscle, also known as involuntary muscle, is a type of muscle that is controlled by the autonomic nervous system and functions without conscious effort. These muscles are found in the walls of hollow organs such as the stomach, intestines, bladder, and blood vessels, as well as in the eyes, skin, and other areas of the body.

Smooth muscle fibers are shorter and narrower than skeletal muscle fibers and do not have striations or sarcomeres, which give skeletal muscle its striped appearance. Smooth muscle is controlled by the autonomic nervous system through the release of neurotransmitters such as acetylcholine and norepinephrine, which bind to receptors on the smooth muscle cells and cause them to contract or relax.

Smooth muscle plays an important role in many physiological processes, including digestion, circulation, respiration, and elimination. It can also contribute to various medical conditions, such as hypertension, gastrointestinal disorders, and genitourinary dysfunction, when it becomes overactive or underactive.

Histamine antagonists, also known as histamine blockers or H1-blockers, are a class of medications that work by blocking the action of histamine, a substance in the body that is released during an allergic reaction. Histamine causes many of the symptoms of an allergic response, such as itching, sneezing, runny nose, and hives. By blocking the effects of histamine, these medications can help to relieve or prevent allergy symptoms.

Histamine antagonists are often used to treat conditions such as hay fever, hives, and other allergic reactions. They may also be used to treat stomach ulcers caused by excessive production of stomach acid. Some examples of histamine antagonists include diphenhydramine (Benadryl), loratadine (Claritin), and famotidine (Pepcid).

It's important to note that while histamine antagonists can be effective at relieving allergy symptoms, they do not cure allergies or prevent the release of histamine. They simply block its effects. It's also worth noting that these medications can have side effects, such as drowsiness, dry mouth, and dizziness, so it's important to follow your healthcare provider's instructions carefully when taking them.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Isoquinolines are not a medical term per se, but a chemical classification. They refer to a class of organic compounds that consist of a benzene ring fused to a piperidine ring. This structure is similar to that of quinoline, but with the nitrogen atom located at a different position in the ring.

Isoquinolines have various biological activities and can be found in some natural products, including certain alkaloids. Some isoquinoline derivatives have been developed as drugs for the treatment of various conditions, such as cardiovascular diseases, neurological disorders, and cancer. However, specific medical definitions related to isoquinolines typically refer to the use or effects of these specific drugs rather than the broader class of compounds.

GTP-binding proteins, also known as G proteins, are a family of molecular switches present in many organisms, including humans. They play a crucial role in signal transduction pathways, particularly those involved in cellular responses to external stimuli such as hormones, neurotransmitters, and sensory signals like light and odorants.

G proteins are composed of three subunits: α, β, and γ. The α-subunit binds GTP (guanosine triphosphate) and acts as the active component of the complex. When a G protein-coupled receptor (GPCR) is activated by an external signal, it triggers a conformational change in the associated G protein, allowing the α-subunit to exchange GDP (guanosine diphosphate) for GTP. This activation leads to dissociation of the G protein complex into the GTP-bound α-subunit and the βγ-subunit pair. Both the α-GTP and βγ subunits can then interact with downstream effectors, such as enzymes or ion channels, to propagate and amplify the signal within the cell.

The intrinsic GTPase activity of the α-subunit eventually hydrolyzes the bound GTP to GDP, which leads to re-association of the α and βγ subunits and termination of the signal. This cycle of activation and inactivation makes G proteins versatile signaling elements that can respond quickly and precisely to changing environmental conditions.

Defects in G protein-mediated signaling pathways have been implicated in various diseases, including cancer, neurological disorders, and cardiovascular diseases. Therefore, understanding the function and regulation of GTP-binding proteins is essential for developing targeted therapeutic strategies.

The thyroid gland is a major endocrine gland located in the neck, anterior to the trachea and extends from the lower third of the Adams apple to the suprasternal notch. It has two lateral lobes, connected by an isthmus, and sometimes a pyramidal lobe. This gland plays a crucial role in the metabolism, growth, and development of the human body through the production of thyroid hormones (triiodothyronine/T3 and thyroxine/T4) and calcitonin. The thyroid hormones regulate body temperature, heart rate, and the production of protein, while calcitonin helps in controlling calcium levels in the blood. The function of the thyroid gland is controlled by the hypothalamus and pituitary gland through the thyroid-stimulating hormone (TSH).

Lipid mobilization, also known as lipolysis, is the process by which fat cells (adipocytes) break down stored triglycerides into free fatty acids and glycerol, which can then be released into the bloodstream and used for energy by the body's cells. This process is regulated by hormones such as adrenaline, noradrenaline, glucagon, and cortisol, which activate enzymes in the fat cell that catalyze the breakdown of triglycerides. Lipid mobilization is an important physiological response to fasting, exercise, and stress, and plays a key role in maintaining energy homeostasis in the body.

Adenine is a purine nucleotide base that is a fundamental component of DNA and RNA, the genetic material of living organisms. In DNA, adenine pairs with thymine via double hydrogen bonds, while in RNA, it pairs with uracil. Adenine is essential for the structure and function of nucleic acids, as well as for energy transfer reactions in cells through its role in the formation of adenosine triphosphate (ATP), the primary energy currency of the cell.

Isoenzymes, also known as isoforms, are multiple forms of an enzyme that catalyze the same chemical reaction but differ in their amino acid sequence, structure, and/or kinetic properties. They are encoded by different genes or alternative splicing of the same gene. Isoenzymes can be found in various tissues and organs, and they play a crucial role in biological processes such as metabolism, detoxification, and cell signaling. Measurement of isoenzyme levels in body fluids (such as blood) can provide valuable diagnostic information for certain medical conditions, including tissue damage, inflammation, and various diseases.

Cytosol refers to the liquid portion of the cytoplasm found within a eukaryotic cell, excluding the organelles and structures suspended in it. It is the site of various metabolic activities and contains a variety of ions, small molecules, and enzymes. The cytosol is where many biochemical reactions take place, including glycolysis, protein synthesis, and the regulation of cellular pH. It is also where some organelles, such as ribosomes and vesicles, are located. In contrast to the cytosol, the term "cytoplasm" refers to the entire contents of a cell, including both the cytosol and the organelles suspended within it.

Sodium fluoride is an inorganic compound with the chemical formula NaF. Medically, it is commonly used as a dental treatment to prevent tooth decay, as it is absorbed into the structure of teeth and helps to harden the enamel, making it more resistant to acid attacks from bacteria. It can also reduce the ability of bacteria to produce acid. Sodium fluoride is often found in toothpastes, mouth rinses, and various dental treatments. However, excessive consumption can lead to dental fluorosis and skeletal fluorosis, which cause changes in bone structure and might negatively affect health.

Cyclic nucleotide phosphodiesterases (PDEs) are a family of enzymes that regulate intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are important second messengers involved in various cellular processes.

Type 1 PDEs (PDE1A, PDE1B, PDE1C) are calcium/calmodulin-regulated enzymes that hydrolyze both cAMP and cGMP with similar catalytic efficiency. They play a crucial role in the regulation of vascular smooth muscle contraction, platelet aggregation, and neuronal excitability.

Dysregulation of PDE1 activity has been implicated in various pathological conditions, including hypertension, cardiovascular diseases, and neurological disorders. Therefore, PDE1 inhibitors have emerged as potential therapeutic agents for the treatment of these conditions.

Thyrotropin, also known as thyroid-stimulating hormone (TSH), is a hormone secreted by the anterior pituitary gland. Its primary function is to regulate the production and release of thyroxine (T4) and triiodothyronine (T3) hormones from the thyroid gland. Thyrotropin binds to receptors on the surface of thyroid follicular cells, stimulating the uptake of iodide and the synthesis and release of T4 and T3. The secretion of thyrotropin is controlled by the hypothalamic-pituitary-thyroid axis: thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates the release of thyrotropin, while T3 and T4 inhibit its release through a negative feedback mechanism.

Sugar phosphates are organic compounds that play crucial roles in various biological processes, particularly in the field of genetics and molecular biology. They are formed by the attachment of a phosphate group to a sugar molecule, most commonly to the 5-carbon sugar ribose or deoxyribose.

In genetics, sugar phosphates form the backbone of nucleic acids, such as DNA and RNA. In DNA, the sugar phosphate backbone consists of alternating deoxyribose (a sugar) and phosphate groups, linked together by covalent bonds between the 5' carbon atom of one sugar molecule and the 3' carbon atom of another sugar molecule. This forms a long, twisted ladder-like structure known as a double helix.

Similarly, in RNA, the sugar phosphate backbone is formed by ribose (a sugar) and phosphate groups, creating a single-stranded structure that can fold back on itself to form complex shapes. These sugar phosphate backbones provide structural support for the nucleic acids and help to protect the genetic information stored within them.

Sugar phosphates also play important roles in energy metabolism, as they are involved in the formation and breakdown of high-energy compounds such as ATP (adenosine triphosphate) and GTP (guanosine triphosphate). These molecules serve as energy currency for cells, storing and releasing energy as needed to power various cellular processes.

Myxomycetes are not a part of human or animal medicine, and thus do not have a medical definition. They are actually a group of organisms commonly known as plasmodial slime molds. These are single-celled amoeboid organisms that can aggregate under certain conditions to form a multinucleate mass called a plasmodium. When the plasmodium matures, it differentiates into fruiting bodies that release spores. Myxomycetes are not plants, animals or fungi, but are classified in their own kingdom, Protista. They are often found on dead plant material in moist, shaded habitats.

The trachea, also known as the windpipe, is a tube-like structure in the respiratory system that connects the larynx (voice box) to the bronchi (the two branches leading to each lung). It is composed of several incomplete rings of cartilage and smooth muscle, which provide support and flexibility. The trachea plays a crucial role in directing incoming air to the lungs during inspiration and outgoing air to the larynx during expiration.

The adrenal cortex is the outer portion of the adrenal gland, which is located on top of the kidneys. It plays a crucial role in producing hormones that are essential for various bodily functions. The adrenal cortex is divided into three zones:

1. Zona glomerulosa: This outermost zone produces mineralocorticoids, primarily aldosterone. Aldosterone helps regulate sodium and potassium balance and thus influences blood pressure by controlling the amount of fluid in the body.
2. Zona fasciculata: The middle layer is responsible for producing glucocorticoids, with cortisol being the most important one. Cortisol regulates metabolism, helps manage stress responses, and has anti-inflammatory properties. It also plays a role in blood sugar regulation and maintaining the body's response to injury and illness.
3. Zona reticularis: The innermost zone produces androgens, primarily dehydroepiandrosterone (DHEA) and its sulfate form (DHEAS). These androgens are weak compared to those produced by the gonads (ovaries or testes), but they can be converted into more potent androgens or estrogens in peripheral tissues.

Disorders related to the adrenal cortex can lead to hormonal imbalances, affecting various bodily functions. Examples include Addison's disease (insufficient adrenal cortical hormone production) and Cushing's syndrome (excessive glucocorticoid levels).

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

Intestinal secretions refer to the fluids and electrolytes that are released by the cells lining the small intestine in response to various stimuli. These secretions play a crucial role in the digestion and absorption of nutrients from food. The major components of intestinal secretions include water, electrolytes (such as sodium, chloride, bicarbonate, and potassium), and enzymes that help break down carbohydrates, proteins, and fats.

The small intestine secretes these substances in response to hormonal signals, neural stimulation, and the presence of food in the lumen of the intestine. The secretion of water and electrolytes helps maintain the proper hydration and pH of the intestinal contents, while the enzymes facilitate the breakdown of nutrients into smaller molecules that can be absorbed across the intestinal wall.

Abnormalities in intestinal secretions can lead to various gastrointestinal disorders, such as diarrhea, malabsorption, and inflammatory bowel disease.

Potassium is a essential mineral and an important electrolyte that is widely distributed in the human body. The majority of potassium in the body (approximately 98%) is found within cells, with the remaining 2% present in blood serum and other bodily fluids. Potassium plays a crucial role in various physiological processes, including:

1. Regulation of fluid balance and maintenance of normal blood pressure through its effects on vascular tone and sodium excretion.
2. Facilitation of nerve impulse transmission and muscle contraction by participating in the generation and propagation of action potentials.
3. Protein synthesis, enzyme activation, and glycogen metabolism.
4. Regulation of acid-base balance through its role in buffering systems.

The normal serum potassium concentration ranges from 3.5 to 5.0 mEq/L (milliequivalents per liter) or mmol/L (millimoles per liter). Potassium levels outside this range can have significant clinical consequences, with both hypokalemia (low potassium levels) and hyperkalemia (high potassium levels) potentially leading to serious complications such as cardiac arrhythmias, muscle weakness, and respiratory failure.

Potassium is primarily obtained through the diet, with rich sources including fruits (e.g., bananas, oranges, and apricots), vegetables (e.g., leafy greens, potatoes, and tomatoes), legumes, nuts, dairy products, and meat. In cases of deficiency or increased needs, potassium supplements may be recommended under the guidance of a healthcare professional.

Guanosine triphosphate (GTP) is a nucleotide that plays a crucial role in various cellular processes, such as protein synthesis, signal transduction, and regulation of enzymatic activities. It serves as an energy currency, similar to adenosine triphosphate (ATP), and undergoes hydrolysis to guanosine diphosphate (GDP) or guanosine monophosphate (GMP) to release energy required for these processes. GTP is also a precursor for the synthesis of other essential molecules, including RNA and certain signaling proteins. Additionally, it acts as a molecular switch in many intracellular signaling pathways by binding and activating specific GTPase proteins.

Colchicine is a medication that is primarily used to treat gout, a type of arthritis characterized by sudden and severe attacks of pain, swelling, redness, and tenderness in the joints. It works by reducing inflammation and preventing the formation of uric acid crystals that cause gout symptoms.

Colchicine is also used to treat familial Mediterranean fever (FMF), a genetic disorder that causes recurrent fevers and inflammation in the abdomen, chest, and joints. It can help prevent FMF attacks and reduce their severity.

The medication comes in the form of tablets or capsules that are taken by mouth. Common side effects of colchicine include diarrhea, nausea, vomiting, and abdominal pain. In rare cases, it can cause more serious side effects such as muscle weakness, nerve damage, and bone marrow suppression.

It is important to follow the dosage instructions carefully when taking colchicine, as taking too much of the medication can be toxic. People with certain health conditions, such as liver or kidney disease, may need to take a lower dose or avoid using colchicine altogether.

Purinergic P1 receptor antagonists are a class of pharmaceutical drugs that block the activity of purinergic P1 receptors, which are a type of G-protein coupled receptor found in many tissues throughout the body. These receptors are activated by extracellular nucleotides such as adenosine and ATP, and play important roles in regulating a variety of physiological processes, including cardiovascular function, neurotransmission, and immune response.

Purinergic P1 receptor antagonists work by binding to these receptors and preventing them from being activated by nucleotides. This can have various therapeutic effects, depending on the specific receptor subtype that is targeted. For example, A1 receptor antagonists have been shown to improve cardiac function in heart failure, while A2A receptor antagonists have potential as anti-inflammatory and neuroprotective agents.

However, it's important to note that the use of purinergic P1 receptor antagonists is still an area of active research, and more studies are needed to fully understand their mechanisms of action and therapeutic potential.

Rap1 GTP-binding proteins are a subfamily of the Ras superfamily of small GTPases, which function as molecular switches that regulate various cellular processes, including cell growth, differentiation, and motility. Rap1 proteins cycle between an inactive GDP-bound state and an active GTP-bound state, and this cycling is regulated by guanine nucleotide exchange factors (GEFs) that promote the exchange of GDP for GTP, and GTPase-activating proteins (GAPs) that stimulate the intrinsic GTPase activity of Rap1, promoting its return to the inactive state.

Rap1 has been implicated in a variety of cellular processes, including cell adhesion, migration, and polarity, as well as cell cycle progression and transcriptional regulation. In particular, Rap1 has been shown to play important roles in the regulation of integrin-mediated adhesion and signaling, and in the control of endothelial cell barrier function. Dysregulation of Rap1 activity has been implicated in a number of human diseases, including cancer and inflammatory disorders.

Adenylate kinase is an enzyme (EC 2.7.4.3) that catalyzes the reversible transfer of a phosphate group between adenine nucleotides, specifically between ATP and AMP to form two ADP molecules. This reaction plays a crucial role in maintaining the energy charge of the cell by interconverting these important energy currency molecules.

The general reaction catalyzed by adenylate kinase is:

AMP + ATP ↔ 2ADP

This enzyme is widely distributed in various organisms and tissues, including mammalian cells. In humans, there are several isoforms of adenylate kinase, located in different cellular compartments such as the cytosol, mitochondria, and nucleus. These isoforms have distinct roles in maintaining energy homeostasis and protecting cells under stress conditions. Dysregulation of adenylate kinase activity has been implicated in several pathological processes, including neurodegenerative diseases, ischemia-reperfusion injury, and cancer.

"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.

Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.

Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.

Gene expression regulation in bacteria refers to the complex cellular processes that control the production of proteins from specific genes. This regulation allows bacteria to adapt to changing environmental conditions and ensure the appropriate amount of protein is produced at the right time.

Bacteria have a variety of mechanisms for regulating gene expression, including:

1. Operon structure: Many bacterial genes are organized into operons, which are clusters of genes that are transcribed together as a single mRNA molecule. The expression of these genes can be coordinately regulated by controlling the transcription of the entire operon.
2. Promoter regulation: Transcription is initiated at promoter regions upstream of the gene or operon. Bacteria have regulatory proteins called sigma factors that bind to the promoter and recruit RNA polymerase, the enzyme responsible for transcribing DNA into RNA. The binding of sigma factors can be influenced by environmental signals, allowing for regulation of transcription.
3. Attenuation: Some operons have regulatory regions called attenuators that control transcription termination. These regions contain hairpin structures that can form in the mRNA and cause transcription to stop prematurely. The formation of these hairpins is influenced by the concentration of specific metabolites, allowing for regulation of gene expression based on the availability of those metabolites.
4. Riboswitches: Some bacterial mRNAs contain regulatory elements called riboswitches that bind small molecules directly. When a small molecule binds to the riboswitch, it changes conformation and affects transcription or translation of the associated gene.
5. CRISPR-Cas systems: Bacteria use CRISPR-Cas systems for adaptive immunity against viruses and plasmids. These systems incorporate short sequences from foreign DNA into their own genome, which can then be used to recognize and cleave similar sequences in invading genetic elements.

Overall, gene expression regulation in bacteria is a complex process that allows them to respond quickly and efficiently to changing environmental conditions. Understanding these regulatory mechanisms can provide insights into bacterial physiology and help inform strategies for controlling bacterial growth and behavior.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

I couldn't find a medical definition for "Depression, Chemical" as it is not a recognized medical term. However, I can provide you with information about chemical imbalances in the brain that are associated with depression.

Major depressive disorder (MDD), commonly referred to as depression, is believed to be caused by a combination of genetic, environmental, and physiological factors. While there is no definitive evidence that depression is solely caused by a "chemical imbalance," neurotransmitter irregularities in the brain are associated with depressive symptoms. Neurotransmitters are chemical messengers that transmit signals in the brain and other parts of the body. Some of the primary neurotransmitters involved in mood regulation include serotonin, norepinephrine, and dopamine.

In depression, it is thought that there may be alterations in the functioning of these neurotransmitter systems, leading to an imbalance. For example:

1. Serotonin: Low levels of serotonin are associated with depressive symptoms. Selective serotonin reuptake inhibitors (SSRIs), a common class of antidepressants, work by increasing the availability of serotonin in the synapse (the space between neurons) to improve communication between brain cells.
2. Norepinephrine: Imbalances in norepinephrine levels can contribute to depressive symptoms and anxiety. Norepinephrine reuptake inhibitors (NRIs), tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs) are medications that target norepinephrine to help alleviate depression.
3. Dopamine: Deficiencies in dopamine can lead to depressive symptoms, anhedonia (the inability to feel pleasure), and motivation loss. Some antidepressants, like bupropion, work by increasing dopamine levels in the brain.

In summary, while "Chemical Depression" is not a recognized medical term, chemical imbalances in neurotransmitter systems are associated with depressive symptoms. However, depression is a complex disorder that cannot be solely attributed to a single cause or a simple chemical imbalance. It is essential to consider multiple factors when diagnosing and treating depression.

Iloprost is a synthetic analogue of prostacyclin, a naturally occurring substance in the body. It is a medication that belongs to a class of drugs called vasodilators, which work by relaxing and widening blood vessels. Iloprost is used to treat pulmonary arterial hypertension (PAH), a condition characterized by high blood pressure in the arteries that supply blood to the lungs. By dilating these blood vessels, iloprost helps reduce the workload on the heart and improve symptoms associated with PAH such as shortness of breath, fatigue, and dizziness.

Iloprost is administered through inhalation using a nebulizer, typically several times a day. It may also be used to prevent or treat episodes of digital ischemia, a condition that causes reduced blood flow to the fingers and toes, leading to pain and tissue damage.

It's important to note that while iloprost can help manage symptoms of PAH and digital ischemia, it does not cure these conditions. Close monitoring by a healthcare provider is necessary to ensure safe and effective use of this medication.

Dexamethasone is a type of corticosteroid medication, which is a synthetic version of a natural hormone produced by the adrenal glands. It is often used to reduce inflammation and suppress the immune system in a variety of medical conditions, including allergies, asthma, rheumatoid arthritis, and certain skin conditions.

Dexamethasone works by binding to specific receptors in cells, which triggers a range of anti-inflammatory effects. These include reducing the production of chemicals that cause inflammation, suppressing the activity of immune cells, and stabilizing cell membranes.

In addition to its anti-inflammatory effects, dexamethasone can also be used to treat other medical conditions, such as certain types of cancer, brain swelling, and adrenal insufficiency. It is available in a variety of forms, including tablets, liquids, creams, and injectable solutions.

Like all medications, dexamethasone can have side effects, particularly if used for long periods of time or at high doses. These may include mood changes, increased appetite, weight gain, acne, thinning skin, easy bruising, and an increased risk of infections. It is important to follow the instructions of a healthcare provider when taking dexamethasone to minimize the risk of side effects.

Fructose-bisphosphatase (FBPase) is an enzyme that plays a crucial role in the regulation of gluconeogenesis, which is the process of generating new glucose molecules from non-carbohydrate sources in the body. Specifically, FBPase is involved in the fourth step of gluconeogenesis, where it catalyzes the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate.

Fructose-1,6-bisphosphate is a key intermediate in both glycolysis and gluconeogenesis, and its conversion to fructose-6-phosphate represents an important regulatory point in these pathways. FBPase is inhibited by high levels of energy charge (i.e., when the cell has plenty of ATP and low levels of ADP), as well as by certain metabolites such as citrate, which signals that there is abundant energy available from other sources.

There are two main isoforms of FBPase in humans: a cytoplasmic form found primarily in the liver and kidney, and a mitochondrial form found in various tissues including muscle and brain. Mutations in the gene that encodes the cytoplasmic form of FBPase can lead to a rare inherited metabolic disorder known as fructose-1,6-bisphosphatase deficiency, which is characterized by impaired gluconeogenesis and hypoglycemia.

'Tumor cells, cultured' refers to the process of removing cancerous cells from a tumor and growing them in controlled laboratory conditions. This is typically done by isolating the tumor cells from a patient's tissue sample, then placing them in a nutrient-rich environment that promotes their growth and multiplication.

The resulting cultured tumor cells can be used for various research purposes, including the study of cancer biology, drug development, and toxicity testing. They provide a valuable tool for researchers to better understand the behavior and characteristics of cancer cells outside of the human body, which can lead to the development of more effective cancer treatments.

It is important to note that cultured tumor cells may not always behave exactly the same way as they do in the human body, so findings from cell culture studies must be validated through further research, such as animal models or clinical trials.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Indomethacin is a non-steroidal anti-inflammatory drug (NSAID) that is commonly used to reduce pain, inflammation, and fever. It works by inhibiting the activity of certain enzymes in the body, including cyclooxygenase (COX), which plays a role in producing prostaglandins, chemicals involved in the inflammatory response.

Indomethacin is available in various forms, such as capsules, suppositories, and injectable solutions, and is used to treat a wide range of conditions, including rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, gout, and bursitis. It may also be used to relieve pain and reduce fever in other conditions, such as dental procedures or after surgery.

Like all NSAIDs, indomethacin can have side effects, including stomach ulcers, bleeding, and kidney damage, especially when taken at high doses or for long periods of time. It may also increase the risk of heart attack and stroke. Therefore, it is important to use indomethacin only as directed by a healthcare provider and to report any unusual symptoms or side effects promptly.

Purinergic P1 receptor agonists are substances that bind to and activate purinergic P1 receptors, which are a type of G protein-coupled receptor found in many tissues throughout the body. These receptors are activated by endogenous nucleotides such as adenosine and its metabolites.

Purinergic P1 receptors include four subtypes: A1, A2A, A2B, and A3. Each of these subtypes has distinct signaling pathways and physiological roles. For example, A1 receptor activation can lead to vasodilation, bradycardia, and anti-inflammatory effects, while A2A receptor activation can increase cyclic AMP levels and have anti-inflammatory effects.

Purinergic P1 receptor agonists are used in various therapeutic applications, including as cardiovascular drugs, antiplatelet agents, and anti-inflammatory agents. Some examples of purinergic P1 receptor agonists include adenosine, regadenoson, and dipyridamole.

It's important to note that the use of these substances should be under medical supervision due to their potential side effects and interactions with other medications.

Muscle contraction is the physiological process in which muscle fibers shorten and generate force, leading to movement or stability of a body part. This process involves the sliding filament theory where thick and thin filaments within the sarcomeres (the functional units of muscles) slide past each other, facilitated by the interaction between myosin heads and actin filaments. The energy required for this action is provided by the hydrolysis of adenosine triphosphate (ATP). Muscle contractions can be voluntary or involuntary, and they play a crucial role in various bodily functions such as locomotion, circulation, respiration, and posture maintenance.

Biological transport refers to the movement of molecules, ions, or solutes across biological membranes or through cells in living organisms. This process is essential for maintaining homeostasis, regulating cellular functions, and enabling communication between cells. There are two main types of biological transport: passive transport and active transport.

Passive transport does not require the input of energy and includes:

1. Diffusion: The random movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.
2. Osmosis: The diffusion of solvent molecules (usually water) across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
3. Facilitated diffusion: The assisted passage of polar or charged substances through protein channels or carriers in the cell membrane, which increases the rate of diffusion without consuming energy.

Active transport requires the input of energy (in the form of ATP) and includes:

1. Primary active transport: The direct use of ATP to move molecules against their concentration gradient, often driven by specific transport proteins called pumps.
2. Secondary active transport: The coupling of the movement of one substance down its electrochemical gradient with the uphill transport of another substance, mediated by a shared transport protein. This process is also known as co-transport or counter-transport.

The myocardium is the middle layer of the heart wall, composed of specialized cardiac muscle cells that are responsible for pumping blood throughout the body. It forms the thickest part of the heart wall and is divided into two sections: the left ventricle, which pumps oxygenated blood to the rest of the body, and the right ventricle, which pumps deoxygenated blood to the lungs.

The myocardium contains several types of cells, including cardiac muscle fibers, connective tissue, nerves, and blood vessels. The muscle fibers are arranged in a highly organized pattern that allows them to contract in a coordinated manner, generating the force necessary to pump blood through the heart and circulatory system.

Damage to the myocardium can occur due to various factors such as ischemia (reduced blood flow), infection, inflammation, or genetic disorders. This damage can lead to several cardiac conditions, including heart failure, arrhythmias, and cardiomyopathy.

Cell surface receptors, also known as membrane receptors, are proteins located on the cell membrane that bind to specific molecules outside the cell, known as ligands. These receptors play a crucial role in signal transduction, which is the process of converting an extracellular signal into an intracellular response.

Cell surface receptors can be classified into several categories based on their structure and mechanism of action, including:

1. Ion channel receptors: These receptors contain a pore that opens to allow ions to flow across the cell membrane when they bind to their ligands. This ion flux can directly activate or inhibit various cellular processes.
2. G protein-coupled receptors (GPCRs): These receptors consist of seven transmembrane domains and are associated with heterotrimeric G proteins that modulate intracellular signaling pathways upon ligand binding.
3. Enzyme-linked receptors: These receptors possess an intrinsic enzymatic activity or are linked to an enzyme, which becomes activated when the receptor binds to its ligand. This activation can lead to the initiation of various signaling cascades within the cell.
4. Receptor tyrosine kinases (RTKs): These receptors contain intracellular tyrosine kinase domains that become activated upon ligand binding, leading to the phosphorylation and activation of downstream signaling molecules.
5. Integrins: These receptors are transmembrane proteins that mediate cell-cell or cell-matrix interactions by binding to extracellular matrix proteins or counter-receptors on adjacent cells. They play essential roles in cell adhesion, migration, and survival.

Cell surface receptors are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and cell growth and differentiation. Dysregulation of these receptors can contribute to the development of numerous diseases, such as cancer, diabetes, and neurological disorders.

Trifluoperazine is an antipsychotic medication that belongs to the class of drugs called phenothiazines. It works by blocking the action of dopamine, a neurotransmitter in the brain, and helps to reduce symptoms of schizophrenia such as hallucinations, delusions, paranoia, and disordered thought. Trifluoperazine may also be used to manage anxiety or agitation in certain medical conditions. It is available in the form of tablets for oral administration. As with any medication, trifluoperazine should be taken under the supervision of a healthcare provider due to potential side effects and risks associated with its use.

3',5'-Cyclic guanosine monophosphate (cGMP) phosphodiesterases are a group of enzymes that play a role in regulating the levels of cGMP, an important intracellular signaling molecule involved in various biological processes. These enzymes catalyze the hydrolysis of cGMP to 5'-GMP, thereby terminating cGMP-mediated signals within cells.

There are several isoforms of cGMP phosphodiesterases, which differ in their regulatory properties, substrate specificity, and cellular distribution. These enzymes can be activated or inhibited by various factors, including drugs, hormones, and neurotransmitters, and play a crucial role in modulating the activity of cGMP-dependent signaling pathways in different tissues and organs.

Dysregulation of cGMP phosphodiesterase activity has been implicated in various diseases, including cardiovascular disorders, pulmonary hypertension, neurodegenerative diseases, and cancer. Therefore, these enzymes are considered important targets for the development of novel therapeutic strategies for the treatment of these conditions.

Octopamine is not primarily used in medical definitions, but it is a significant neurotransmitter in invertebrates, including insects. It is the equivalent to noradrenaline (norepinephrine) in vertebrates and has similar functions related to the "fight or flight" response, arousal, and motivation. Insects use octopamine for various physiological processes such as learning, memory, regulation of heart rate, and modulation of muscle contraction. It also plays a role in the social behavior of insects like aggression and courtship.

5'-Nucleotidase is an enzyme that is found on the outer surface of cell membranes, including those of liver cells and red blood cells. Its primary function is to catalyze the hydrolysis of nucleoside monophosphates, such as adenosine monophosphate (AMP) and guanosine monophosphate (GMP), to their corresponding nucleosides, such as adenosine and guanosine, by removing a phosphate group from the 5' position of the nucleotide.

Abnormal levels of 5'-Nucleotidase in the blood can be indicative of liver or bone disease. For example, elevated levels of this enzyme in the blood may suggest liver damage or injury, such as that caused by hepatitis, cirrhosis, or alcohol abuse. Conversely, low levels of 5'-Nucleotidase may be associated with certain types of anemia, including aplastic anemia and paroxysmal nocturnal hemoglobinuria.

Medical professionals may order a 5'-Nucleotidase test to help diagnose or monitor the progression of these conditions. It is important to note that other factors, such as medication use or muscle damage, can also affect 5'-Nucleotidase levels, so results must be interpreted in conjunction with other clinical findings and diagnostic tests.

The adrenal glands are a pair of endocrine glands that are located on top of the kidneys. Each gland has two parts: the outer cortex and the inner medulla. The adrenal cortex produces hormones such as cortisol, aldosterone, and androgens, which regulate metabolism, blood pressure, and other vital functions. The adrenal medulla produces catecholamines, including epinephrine (adrenaline) and norepinephrine (noradrenaline), which help the body respond to stress by increasing heart rate, blood pressure, and alertness.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

Tyrosine transaminase, also known as tyrosine aminotransferase or TAT, is an enzyme that plays a crucial role in the metabolism of the amino acid tyrosine. This enzyme catalyzes the transfer of an amino group from tyrosine to a ketoacid, such as alpha-ketoglutarate, resulting in the formation of a new amino acid, glutamate, and a ketone derivative of tyrosine.

Tyrosine transaminase is primarily found in the liver and its activity can be used as a biomarker for liver function. Increased levels of this enzyme in the blood may indicate liver damage or disease, such as hepatitis or cirrhosis. Therefore, measuring tyrosine transaminase activity is often part of routine liver function tests.

I'm sorry for any confusion, but "Prostaglandins D" is not a recognized or established term in the field of medicine or physiology. Prostaglandins are a group of lipid compounds that are synthesized in the body from fatty acids and have diverse hormone-like effects in the body. They are classified into several types based on their chemical structure and biological activity, including Prostaglandin D (PGD), but referring to "Prostaglandins D" as a single entity is not standard.

Prostaglandin D (PGD) itself is a type of prostaglandin that is rapidly converted to other compounds in the body and has been studied for its potential role in various physiological processes, such as inflammation, fever, and blood flow regulation. However, it's important to note that specific medical definitions or clinical uses related to "Prostaglandins D" are not well-established.

If you have any further questions or need more information about a specific aspect of prostaglandins or their role in the body, I would be happy to help!

... from slime molds are a distinct family of G-protein coupled receptors. These receptors control development ... In D. discoideum, the cyclic AMP receptors coordinate aggregation of individual cells into a multicellular organism, and ...
... (also called c-di-AMP and c-di-adenosine monophosphate) is a second messenger used in signal transduction in ... Cyclic di-AMP has also been linked to bacterial RNA synthesis inhibition. c-di-AMP stimulates the production of (p)ppGpp, an ... At high concentrations, cyclic di-AMP binds to receptor and target proteins to control specific pathways. Elevated c-di-AMP ... December 2012). "The helicase DDX41 recognizes the bacterial secondary messengers cyclic di-GMP and cyclic di-AMP to activate a ...
May 2013). "Cyclic [G(2',5')pA(3',5')p] is the metazoan second messenger produced by DNA-activated cyclic GMP-AMP synthase". ... Wu J, Sun L, Chen X, Du F, Shi H, Chen C, Chen ZJ (February 2013). "Cyclic GMP-AMP is an endogenous second messenger in innate ... The human gene encoding cGAS is MB21D1 on chromosome 6. Sun L, Wu J, Du F, Chen X, Chen ZJ (February 2013). "Cyclic GMP-AMP ... Zhang X, Shi H, Wu J, Zhang X, Sun L, Chen C, Chen ZJ (July 2013). "Cyclic GMP-AMP containing mixed phosphodiester linkages is ...
... cyclic-AMP 5′-nucleotidohydrolase. It catalyses the following reaction adenosine 3′,5′-cyclic phosphate + H2O ⇌ {\displaystyle ... 3',5'-cyclic-AMP+phosphodiesterase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology ( ... 3′,5′-cyclic-AMP phosphodiesterase (EC 3.1.4.53, cAMP-specific phosphodiesterase, cAMP-specific PDE, PDE1, PDE2A, PDE2B, PDE4, ... Lugnier C, Keravis T, Le Bec A, Pauvert O, Proteau S, Rousseau E (November 1999). "Characterization of cyclic nucleotide ...
"Pseudohypoparathyroidism". Tze, W. J.; Saunders, J.; Drummond, G. I. (1975). "Urinary 3'5' cyclic AMP. Diagnostic test in ...
Botsford, J L; Harman, J G (March 1992). "Cyclic AMP in prokaryotes". Microbiological Reviews. 56 (1): 100-122. doi:10.1128/ ... Montminy, M. (1997). "Transcriptional regulation by cyclic AMP". Annual Review of Biochemistry. 66: 807-822. doi:10.1146/ ... Cyclic adenosine monophosphate (cAMP) is a signal molecule whose prevalence is inversely proportional to that of glucose. It ...
... and cyclic AMP.[supplied by OMIM] Pituitary-specific positive transcription factor 1 has been shown to interact with GATA2 and ...
... cyclic-AMP-forming). It catalyzes the following reaction: ATP = 3′,5′-cyclic AMP + diphosphate It has key regulatory roles in ... Cyclic AMP is an important molecule in eukaryotic signal transduction, a so-called second messenger. Adenylyl cyclases are ... All classes of adenylyl cyclase catalyse the conversion of adenosine triphosphate (ATP) to 3',5'-cyclic AMP (cAMP) and ... which transmits a signal by converting adenosine triphosphate to cyclic adenosine monophosphate (cAMP). cAMP is known as a ...
Jones GH, Venuti MC, Alvarez R, Bruno JJ, Berks AH, Prince A (February 1987). "Inhibitors of cyclic AMP phosphodiesterase. 1. ...
Cyclic AMP and cyclic GMP phosphodiesterase". Biochim. Biophys. Acta. 334: 368-377. doi:10.1016/0005-2744(74)90180-6. Portal: ... Other names in common use include guanosine cyclic 3',5'-phosphate phosphodiesterase, cyclic GMP phosphodiesterase, cyclic 3′,5 ... The enzyme 3′,5′-cyclic-GMP phosphodiesterase (EC 3.1.4.35) catalyzes the reaction guanosine 3′,5′-cyclic phosphate + H2O ⇌ {\ ... cyclic guanosine 3′,5′-phosphate phosphodiesterase, cGMP phosphodiesterase, cGMP-PDE, and cyclic guanosine 3′,5′-phosphate ...
Cyclic AMP acts by activating cAMP-sensitive pathways such as protein kinase A and EPAC1. Its derivatives include colforsin ... Forskolin is commonly used in biochemistry to raise levels of cyclic AMP (cAMP) in the study and research of cell physiology. ... Adenylyl cyclase Cyclic AMP "Forskolin" (PDF). Sigma Aldrich. "Forskolin". Drugs.com. 2018. Retrieved 23 March 2018. Alasbahi, ... Forskolin is commonly used in laboratory research to increase levels of cyclic AMP by stimulation of adenylate cyclase. ...
... is a cyclic AMP binding protein. Members of the RAS subfamily of GTPases function in signal transduction as GTP/GDP- ...
... affect components of the cyclic AMP system; and influence other chemical pathways. The enzyme paraoxonase 1 (PON1) detoxifies ... likely associated with changes to the cyclic AMP system. Moreover, experiments with zebrafish showed significant detriments to ...
... was later termed cyclic AMP. Even though the discovery of cyclic AMP and the idea of second messengers were of great importance ... namely cyclic adenosine monophosphate, or cyclic AMP. Sutherland was born on November 19, 1915, in Burlingame, Kansas. The ... Sutherland, E. W; Robison, G. A (1969). "The role of cyclic AMP in the control of carbohydrate metabolism". Diabetes. 18 (12): ... He continued his work on cyclic AMP, receiving financial support from the Career Investigatorship awarded to him by the ...
This cyclic AMP decreases the smooth muscle tone. This drug is 10,000-times more lipid soluble than the short acting beta-2 ... They act on the enzyme adenyl cyclase which increases the concentration of cAMP (Cyclic adenosine monophosphate). ...
Modulation of inflammation and immunity by cyclic AMP. Science 184: 19 28, 1974. Shearer GM. Cell mediated cytotoxicity to ...
"Differential signaling of cyclic AMP: opposing effects of exchange protein directly activated by cyclic AMP and cAMP-dependent ... Ponsioen B, Gloerich M, Ritsma L, Rehmann H, Bos JL, Jalink K (May 2009). "Direct spatial control of Epac1 by cyclic AMP". ... Rehmann H, Das J, Knipscheer P, Wittinghofer A, Bos JL (February 2006). "Structure of the cyclic-AMP-responsive exchange factor ... Almahariq M, Mei FC, Cheng X (February 2014). "Cyclic AMP sensor EPAC proteins and energy homeostasis". Trends in Endocrinology ...
Bhatt DH, Otto SJ, Depoister B, Fetcho JR (July 2004). "Cyclic AMP-induced repair of zebrafish spinal circuits". Science. 305 ( ...
Cyclic GMP-AMP synthase is a protein that in humans is encoded by the CGAS gene. It's an enzyme, a nucleotidyltransferase, a ... "CGAS cyclic GMP-AMP synthase [ Homo sapiens (human) ]". Retrieved 2020-09-12. PDBe-KB provides an overview of all the structure ... information available in the PDB for Human Cyclic GMP-AMP synthase (MB21D1) v t e (Articles with short description, Short ... cyclic GMP-AMP synthase. GRCh38: Ensembl release 89: ENSG00000164430 - Ensembl, May 2017 GRCm38: Ensembl release 89: ...
Some species use cyclic AMP as the signal; others such as Polysphondylium violaceum use a dipeptide known as glorin. In plants ...
Rodríguez, Carlos Iván; Setaluri, Vijayasaradhi (2014). "Cyclic AMP (cAMP) signaling in melanocytes and melanoma". Arch. ... which produces cyclic adenosine monophosphate (cAMP), which activates protein kinase A (PKA), which activates by protein ...
... (cyclic GMP-AMP, cGAMP) is the first cyclic di-nucleotide found in ... May 3, 2013). "Cyclic [G(2′,5′)pA(3′,5′)p] Is the Metazoan Second Messenger Produced by DNA-Activated Cyclic GMP-AMP Synthase ... Wu, J; Sun, L; Chen, X; Du, F; Shi, H; Chen, C; Chen, ZJ (Dec 20, 2012). "Cyclic GMP-AMP is an endogenous second messenger in ... Sun, L; Wu, J; Du, F; Chen, X; Chen, ZJ (Dec 20, 2012). "Cyclic GMP-AMP synthase is a cytosolic DNA sensor that activates the ...
Guild BC, Strominger JL (1984). "HLA-A2 antigen phosphorylation in vitro by cyclic AMP-dependent protein kinase. Sites of ... Bourdeau I, Stratakis CA (2002). "Cyclic AMP-dependent signaling aberrations in macronodular adrenal disease". Ann. N. Y. Acad ... transforming sequence formed by the fusion of ret tyrosine kinase and the regulatory subunit RI alpha of cyclic AMP-dependent ...
"Entrez Gene: ARPP-19 cyclic AMP phosphoprotein, 19 kD". Human ARPP19 genome location and ARPP19 gene details page in the UCSC ...
Cyclic di-AMP Tamayo R, Pratt JT, Camilli A (2007). "Roles of cyclic diguanylate in the regulation of bacterial pathogenesis". ... to be regulated by cyclic di-GMP. Riboswitches called the cyclic di-GMP-I riboswitch and cyclic di-GMP-II riboswitch regulate ... Cyclic di-GMP (also called cyclic diguanylate and c-di-GMP) is a second messenger used in signal transduction in a wide variety ... The PilZ domain has been shown to bind cyclic di-GMP and is believed to be involved in cyclic di-GMP-dependent regulation, but ...
... is a cyclic nucleotide derived from guanosine triphosphate (GTP). cGMP acts as a second messenger much like cyclic AMP. Its ... Cyclic adenosine monophosphate (cAMP) 8-Bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) Francis SH, Corbin JD (August ... Numerous cyclic nucleotide phosphodiesterases (PDE) can degrade cGMP by hydrolyzing cGMP into 5'-GMP. PDE 5, -6 and -9 are cGMP ... Brown RL, Strassmaier T, Brady JD, Karpen JW (2006). "The pharmacology of cyclic nucleotide-gated channels: emerging from the ...
... 's function is related to two substances: cyclic AMP and cyclic GMP. They are derivatives of ATP and GTP, respectively, ... AMP levels decreased from normal after .06 microgram dose, then increased for all larger doses. AMP and GMP are both secondary ... cyclic AMP) and its ability to poison via a mechanism different from that of any other known organophosphorus toxicant makes it ... "Activity-Dependent Regulation of HCN Pacemaker Channels by Cyclic AMP". Neuron. 36 (3): 451-461. doi:10.1016/S0896-6273(02) ...
Table 1 McDonald, M-L; MacMullen, C; Liu, D J; Leal, S M; Davis, R L (2 October 2012). "Genetic association of cyclic AMP ...
Its gene is regulated through the cyclic AMP signaling pathway. The protein binds, internalizes and degrades oxidized low- ...
Cyclic AMP-regulated phosphoprotein, 21 kD, also known as ARPP-21, is a human gene. GRCh38: Ensembl release 89: ENSG00000172995 ... "Entrez Gene: ARPP-21 cyclic AMP-regulated phosphoprotein, 21 kD". Human ARPP21 genome location and ARPP21 gene details page in ... a cyclic AMP-regulated phosphoprotein enriched in the basal ganglia". Neuropharmacology. 39 (9): 1637-44. doi:10.1016/s0028- ...
Cyclic AMP receptors from slime molds are a distinct family of G-protein coupled receptors. These receptors control development ... In D. discoideum, the cyclic AMP receptors coordinate aggregation of individual cells into a multicellular organism, and ...
... Nat Chem Biol. 2016 Aug;12(8):586-92. doi: 10.1038/nchembio.2098. Epub 2016 Jun ... cyclic AMP (cAMP), by altering the activity of the cAMP-degrading phosphodiesterase PDE3B. Biochemical studies of the copper- ... Cyclic AMP / metabolism* * Cyclic Nucleotide Phosphodiesterases, Type 3 / chemistry * Cyclic Nucleotide Phosphodiesterases, ...
Learn about Cyclic AMP Response Element Modulator at online-medical-dictionary.org ... Cyclic AMP response element modulator is a basic leucine zipper transcription factor that is regulated by CYCLIC AMP. It plays ... Cyclic AMP Response Element Modulator. Synonyms. CREM Protein, alpha Isoform. CREM Protein, epsilon Isoform. CREM Protein, ...
The cyclic GMP-AMP synthase (cGAS)-Stimulator of Interferon Genes (STING) pathway is a critical defender to sense various ... cGAS recognizes the pathogenic DNA in the cytosol and then synthesizes 2′3′-cyclic GMP-AMP (2′3′cGAMP). As the second messenger ... cGAS recognizes the pathogenic DNA in the cytosol and then synthesizes 23-cyclic GMP-AMP (23-cGAMP). As the second ... The cyclic GMP-AMP synthase (cGAS)-Stimulator of Interferon Genes (STING) pathway is a critical defender to sense various ...
Blumberg JB The role of cerebral cyclic AMP in the action of psychotropic drugs: in vivo and in vitro studies Dissertation ... "The role of cerebral cyclic AMP in the action of psychotropic drugs: in vivo and in vitro studies". ... "The role of cerebral cyclic AMP in the action of psychotropic drugs: in vivo and in vitro studies" Dissertation Abstr. Intern B ...
Ruoff, H.J.; Sewing, K.F. 1973: Cyclic amp in the rat gastric mucosa after penta gastrin histamine and carbachol Acta Hepato- ... Early increase of cyclic amp in histamine stimulated piglet gastric mucosa. Ekblad, E.B.M.; Machen, T.; Licko, V.; Rutten, M.. ... Puşcaş, I.; Voicu, L. 1980: 3',5'cyclic AMP, histamine and carbonic anhydrase of the gastric mucosa Revista de ... Shirakawa, T.; Matsumoto, H.; Ohe, K.; Miyoshi, A. 1980: The increase in cyclic AMP content in the isolated guinea pig gastric ...
... cyclic AMP and the secretory response of piglet gastric mucosa ... Ruoff, H.J.; Sewing, K.F. 1973: Cyclic amp in the rat gastric ... Histamine, cyclic AMP and the secretory response of piglet gastric mucosa. Ekblad, E.; Machen, T.; Licko, V.R.tten, M.. ... Ryberg, B.; Sjostrand, S.E.; Olbe, L. 1977: The acid secretory effects of histamine and di butyryl cyclic amp on the isolated ... Puşcaş, I.; Voicu, L. 1980: 3',5'cyclic AMP, histamine and carbonic anhydrase of the gastric mucosa Revista de ...
Role of Adenosine 3 , 5-Monophosphate (Cyclic AMP) in Actions of Catecholamines. Theodore W. Rall ... Role of Adenosine 3 , 5-Monophosphate (Cyclic AMP) in Actions of Catecholamines. Theodore W. Rall ... Role of Adenosine 3 , 5-Monophosphate (Cyclic AMP) in Actions of Catecholamines. Theodore W. Rall ... Role of Adenosine 3 , 5-Monophosphate (Cyclic AMP) in Actions of Catecholamines ...
Longitudinal Studies of Platelet Cyclic AMP during Healthy Pregnancy and Pregnancies at Risk of Pre-Eclampsia E. H. Horn; E. H ... E. H. Horn, J. A. Cooper, E. Hardy, S. Heptinstall, P. C. Rubin; Longitudinal Studies of Platelet Cyclic AMP during Healthy ... 3. Basal platelet cyclic AMP levels, and those in the presence of a phosphodiesterase inhibitor, did not change throughout the ... 1. Platelet behaviour in vitro in relation to cyclic AMP was studied longitudinally during pregnancy and in the same women when ...
Altered Regulation of the D1 Dopamine Receptor in Mutant Chinese Hamster Ovary Cells Deficient in Cyclic AMP-Dependent Protein ... Altered Regulation of the D1 Dopamine Receptor in Mutant Chinese Hamster Ovary Cells Deficient in Cyclic AMP-Dependent Protein ... Altered Regulation of the D1 Dopamine Receptor in Mutant Chinese Hamster Ovary Cells Deficient in Cyclic AMP-Dependent Protein ... Altered Regulation of the D1 Dopamine Receptor in Mutant Chinese Hamster Ovary Cells Deficient in Cyclic AMP-Dependent Protein ...
Cyclic AMP Responsive Element Binding Proteins Are Involved in Emergency Granulopoiesis through the Upregulation of CCAAT/ ... Cyclic AMP responsive element binding proteins are involved in emergency granulopoiesis through the upregulation of CCAAT/ ... The results demonstrated that two cyclic AMP responsive elements (CREs) in the proximal promoter region of C/EBPβ were involved ...
Endothelin receptor type A signals both the accumulation of inositol phosphates and the inhibition of cyclic AMP generation in ... Endothelin receptor type A signals both the accumulation of inositol phosphates and the inhibition of cyclic AMP generation in ... Endothelin receptor type A signals both the accumulation of inositol phosphates and the inhibition of cyclic AMP generation in ... Endothelin receptor type A signals both the accumulation of inositol phosphates and the inhibition of cyclic AMP generation in ...
Cyclic 3,5-Adenosine Monophosphate Mediates Dopamine D1-Stimulated Growth Hormone Release from Goldfish Pituitary Cells ... Non-Canonical Allostery in Cyclic Nucleotide Dependent Kinases Journal Articles * Protein kinase A-catalyzed phosphorylation of ...
... cyclic GMP-AMP sodium) is a endogenous cGAMP in mammalian cells. 2,3-cGAMP sodium binds to STING with a high affinity and is ... cyclic GMP-AMP sodium) contains two distinct phosphodiester linkages, one between 2′-OH of GMP and 5′-phosphate of AMP, and the ... 2,3-cGAMP2734858-36-52-3-cyclic GMP-AMPEndogenous MetaboliteSTINGIFNARStimulator of Interferon GenesTMEM173MITAERISMPYS ... 2,3-cGAMP sodium (Synonyms: 2-3-cyclic GMP-AMP sodium) Cat. No.: HY-100564A Purity: 99.72% FAQs ...
Growth regulatory effects of cyclic AMP and polyamine depletion are dissociable in cultured mouse lymphoma cells. L C ... L C McConlogue, L J Marton, P Coffino; Growth regulatory effects of cyclic AMP and polyamine depletion are dissociable in ... and because cellular polyamine levels do not drop in dibuturyl cyclic AMP (Bt2cAMP)-arrested cells. The hypothesis that ... two hypotheses regarding the relationship of growth arrest mediated by polyamine limitation to that mediated by cyclic AMP ( ...
Cyclic AMP-Dependent Protein Kinases [D08.811.913.696.620.682.700.150.125]. *Cyclic AMP-Dependent Protein Kinase Type II [ ... Cyclic AMP-Dependent Protein Kinases [D12.644.360.200.125]. *Cyclic AMP-Dependent Protein Kinase Type II [D12.644.360.200. ... Cyclic AMP-Dependent Protein Kinases [D12.776.476.200.125]. *Cyclic AMP-Dependent Protein Kinase Type II [D12.776.476.200. ... Cyclic AMP-Dependent Protein Kinase Type II*Cyclic AMP-Dependent Protein Kinase Type II ...
Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3,5-cyclic adenosine monophosphate) is a second messenger, or cellular ... cyclic AMP). Synthesis edit Cyclic AMP is synthesized from ATP by adenylate cyclase located on the inner side of the plasma ... Since cyclic AMP is a second messenger and plays vital role in cell signalling, it has been implicated in various disorders but ... In eukaryotes, cyclic AMP works by activating protein kinase A (PKA, or cAMP-dependent protein kinase). PKA is normally ...
Roles of cyclic AMP in regulation of phototaxis in chlamydomonas reinhardtii. In: Biologia. 2009 ; Vol. 64, No. 6. pp. 1058- ... Roles of cyclic AMP in regulation of phototaxis in chlamydomonas reinhardtii. Biologia. 2009 Oct;64(6):1058-1065. doi: 10.2478/ ... Roles of cyclic AMP in regulation of phototaxis in chlamydomonas reinhardtii. Maskiet Boonyareth, Jureepan Saranak, Darawan ... Roles of cyclic AMP in regulation of phototaxis in chlamydomonas reinhardtii. / Boonyareth, Maskiet; Saranak, Jureepan; ...
Gentleman S Adenosine Cyclic 3,5-Monophosphate in the Liver Fluke, fasciola hepatica. I. Activation of Adenylate Cyclase by 5 ... The degree of activation by cyclic AMP was inversely correlated with endogenous cyclic AMP and 5HT concentration. Incubation of ... The enhanced levels of cyclic AMP were preserved by both caffeine and papaverine, and NaF up to 5 mM caused a specific ... 0.1 mM LSD (Sandoz) and 1 mM amphetamine (Sigma-Chem.) both strongly stimulated motility but had no effect on cyclic AMP levels ...
... and on the activity of cyclic nucleotide phosphodiesterases (PDE) whose role is to degrade cAMP into 5-AMP. The PDE ... cyclic monophosphate (cAMP) is known to play highly important roles in sperm motility and acrosomal exocytosis. It is known to ... Cyclic AMP (adenosine 3, 5-cyclic monophosphate) is an important player in sperm function. It is involved in flagellar ... Dibutyryl cyclic AMP decreases capacitation time in vitro in mouse spermatozoa. J Reprod Fertil. 1981;62(1):63-72. pmid:6262510 ...
"Cyclic AMP-Dependent Protein Kinases" by people in this website by year, and whether "Cyclic AMP-Dependent Protein Kinases" was ... Cyclic Nucleotide-Regulated Protein Kinases [D08.811.913.696.620.682.700.150]. *Cyclic AMP-Dependent Protein Kinases [D08.811. ... "Cyclic AMP-Dependent Protein Kinases" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, ... A group of enzymes that are dependent on CYCLIC AMP and catalyze the phosphorylation of SERINE or THREONINE residues on ...
Dive into the research topics of Fluoride-induced changes in renal papillary cyclic-AMP. Together they form a unique ...
Cyclic AMP Mediation of Epithelial Cell Function Goldenring, James Richard Vanderbilt University Medical Center, Nashville, TN ...
Cyclic AMP-Dependent Protein Kinases [D08.811.913.696.620.682.700.150.125]. *Cyclic AMP-Dependent Protein Kinase Type II [ ... Cyclic AMP-Dependent Protein Kinases [D12.644.360.200.125]. *Cyclic AMP-Dependent Protein Kinase Type II [D12.644.360.200. ... Cyclic AMP-Dependent Protein Kinases [D12.776.476.200.125]. *Cyclic AMP-Dependent Protein Kinase Type II [D12.776.476.200. ... Cyclic AMP-Dependent Protein Kinase Type II*Cyclic AMP-Dependent Protein Kinase Type II ...
Hackley, C. R., Mazzoni, E. O., & Blau, J. (2018). cAMPr: A single-wavelength fluorescent sensor for cyclic AMP. Science ... Hackley, CR, Mazzoni, EO & Blau, J 2018, cAMPr: A single-wavelength fluorescent sensor for cyclic AMP, Science signaling, vol ... cAMPr: A single-wavelength fluorescent sensor for cyclic AMP. / Hackley, Christopher R.; Mazzoni, Esteban O.; Blau, Justin. In ... cAMPr: A single-wavelength fluorescent sensor for cyclic AMP. Science signaling. 2018 Mar 6;11(520):eaah3738. doi: 10.1126/ ...
Home / Essay Examples / Apoptosis / Cyclic GMP-AMP Synthase Cyclic GMP-AMP Synthase. ... papersowl.com/examples/cyclic-gmp-amp-synthase/ > MLA PapersOwl.com. (2019). Cyclic GMP-AMP Synthase. [Online]. Available at: ... papersowl.com/examples/cyclic-gmp-amp-synthase/ > ASA "Cyclic GMP-AMP Synthase," PapersOwl.com, 14-May-2019. [Online]. ... 2019). Cyclic GMP-AMP Synthase. [Online]. Available at: https://papersowl.com/examples/cyclic-gmp-amp-synthase/ [Accessed: 6- ...
Treatment of a subclone of the PC12 pheochromocytoma cell line, PC8b, with either dexamethasone or 8-bromo cyclic AMP resulted ... Regulation of tyrosine hydroxylase mRNA by glucocorticoid and cyclic AMP in a rat pheochromocytoma cell line. Isolation of a ... "Regulation of tyrosine hydroxylase mRNA by glucocorticoid and cyclic AMP in a rat pheochromocytoma cell line. Isolation of a ... Regulation of tyrosine hydroxylase mRNA by glucocorticoid and cyclic AMP in a rat pheochromocytoma cell line. Isolation of a ...
Dive into the research topics of Arguments against a mediating role of the denylate cyclase - cyclic amp system in the ... Arguments against a mediating role of the denylate cyclase - cyclic amp system in the ototoxic action of loop diuretics. ...
Cyclic AMP-dependent cell responses under shear stress. 11ème Forum des Jeunes Chercheurs en Génie Biologique et Médical, Jun ...
H-Human M-Mouse R-Rat Hm-Hamster Mk-Monkey Vir-Virus Mi-Mink C-Chicken Dm-D. melanogaster X-Xenopus Z-Zebrafish B-Bovine Dg-Dog Pg-Pig Sc-S. cerevisiae Ce-C. elegans Hr-Horse GP-Guinea Pig Rab-Rabbit All-All Species Expected ...
  • Cyclic AMP receptors from slime molds are a distinct family of G-protein coupled receptors. (wikipedia.org)
  • In D. discoideum, the cyclic AMP receptors coordinate aggregation of individual cells into a multicellular organism, and regulate the expression of a large number of developmentally-regulated genes. (wikipedia.org)
  • Cell surface cyclic AMP receptors are not included (CYCLIC AMP RECEPTORS), nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins, which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES. (bvsalud.org)
  • In addition, cAMP binds to and regulates the function of ion channels such as the HCN channels and a few other cyclic nucleotide-binding proteins such as Epac1 and RAPGEF2 . (wikipedia.org)
  • To test whether either cyclic nucleotide influenced the direction, their pre-stimulus levels were pharmacologically manipulated. (syr.edu)
  • Sperm intracellular cAMP levels depend on the activity of adenylyl cyclases, mostly SACY, though transmembrane-containing adenylyl cyclases are also present, and on the activity of cyclic nucleotide phosphodiesterases (PDE) whose role is to degrade cAMP into 5'-AMP. (plos.org)
  • Goupil S, Maréchal L, El Hajj H, Tremblay M-È, Richard FJ, Leclerc P (2016) Identification and Localization of the Cyclic Nucleotide Phosphodiesterase 10A in Bovine Testis and Mature Spermatozoa. (plos.org)
  • Based on the sequence differences between CRP and cyclic nucleotide gated channel, three mutants of CRP were constructed: deletion (residues 54-56 in loop 3 were deleted), insertion (loop 4 was lengthened by 5 residues between Glu-78 and Gly-79) and double mutants. (utmb.edu)
  • Thus, the roles played by loop 3 in CRP may represent a more common mechanism employed by cyclic nucleotide binding domain in modulating ligand binding affinity and intramolecular communication. (utmb.edu)
  • Chen, R & Lee, JC 2003, ' Functional roles of loops 3 and 4 in the cyclic nucleotide binding domain of cyclic AMP receptor protein from Escherichia coli ', Journal of Biological Chemistry , vol. 278, no. 15, pp. 13235-13243. (utmb.edu)
  • Cyclic AMP receptor protein was originally identified as a catabolite gene activator protein. (bvsalud.org)
  • The cyclic GMP-AMP synthase (cGAS)-Stimulator of Interferon Genes (STING) pathway is a critical defender to sense various pathogens and trigger innate immunity of mammalian cells. (frontiersin.org)
  • Dysfunctional telomeres trigger cellular senescence mediated by cyclic GMP-AMP synthase. (bvsalud.org)
  • We found that this phenomenon is caused not by telomere shortening , but by cyclic GMP -AMP synthase (cGAS) recognizing cytosolic chromatin fragments and then activating the stimulator of interferon genes ( STING ) cytosolic DNA -sensing pathway and downstream interferon signaling. (bvsalud.org)
  • Using a mouse model of genetic copper misregulation, in combination with pharmacological alterations in copper status and imaging studies in a 3T3-L1 white adipocyte model, we found that copper regulates lipolysis at the level of the second messenger, cyclic AMP (cAMP), by altering the activity of the cAMP-degrading phosphodiesterase PDE3B. (nih.gov)
  • 3. Basal platelet cyclic AMP levels, and those in the presence of a phosphodiesterase inhibitor, did not change throughout the period of the study. (portlandpress.com)
  • cAMP decomposition into AMP is catalyzed by the enzyme phosphodiesterase . (wikipedia.org)
  • Although cGMP activates the cyclic AMP (cAMP)-dependent pathway by suppressing cGMP-inhibited phosphodiesterase 3 (PDE3), the effects of the cAMP-dependent pathway on γ-globin gene expression are unknown. (elsevierpure.com)
  • 4. By contrast, platelet cyclic AMP accumulation in response to a variety of adenylate cyclase stimulators was reduced from early pregnancy, throughout the gestational period, compared with post-natally. (portlandpress.com)
  • 5. Compared with healthy women, platelets from women with a previous history of pre-eclampsia tended to accumulate less cyclic AMP in response to adenylate cyclase stimulators. (portlandpress.com)
  • Cyclic AMP is synthesized from ATP by adenylate cyclase located on the inner side of the plasma membrane and anchored at various locations in the interior of the cell. (wikipedia.org)
  • Fasciola hepatica were collected from fresh beef livers and particulate fractions of whole flukes, 'tails' or 'heads' (anterior ends) assayed for adenylate cyclase (AC) activity and cyclic AMP concentration using a protein binding assay. (erowid.org)
  • In the presence of O.i mM 5HT, AC activity in the fluke particles was inhibited by 0.5 mcM LSD, and LSD also antagonized the 5HT stimulated increase in cyclic AMP levels, Adenine, adenosine, histamine (Calbiochem), adrenaline (Mann), tryptophan, dopamine, GTP (Sigma - Chem. (erowid.org)
  • Fetal hemoglobin inducers such as hemin, butyrate, and hydroxyurea stimulate γ-globin gene expression by activating the cyclic GMP (cGMP)-dependent pathway. (elsevierpure.com)
  • The models of most immune evasion during innate immune responses are conserved, including altering the post-transcriptional modifications (PTMs) of vital proteins to inactivate or degrade these components, eluding DNA sensing from PRRs, decreasing cyclic GMP-AMP (cGAMP) cellular abundance, and modifying metabolism approach in host cells ( Eaglesham and Kranzusch, 2020 ). (frontiersin.org)
  • Alterations in cyclic amp metabolism associated with photoreceptor cel" by R N. Lolley, S Y. Schmidt et al. (jax.org)
  • Alterations in cyclic amp metabolism associated with photoreceptor cell degeneration in the c3h mouse. (jax.org)
  • Cyclic AMP binds to specific locations on the regulatory units of the protein kinase, and causes dissociation between the regulatory and catalytic subunits, thus enabling those catalytic units to phosphorylate substrate proteins. (wikipedia.org)
  • A group of enzymes that are dependent on CYCLIC AMP and catalyze the phosphorylation of SERINE or THREONINE residues on proteins. (rush.edu)
  • Cyclic adenosine monophosphate ( cAMP , cyclic AMP , or 3',5'-cyclic adenosine monophosphate ) is a second messenger , or cellular signal occurring within cells, that is important in many biological processes. (wikipedia.org)
  • Earl Sutherland of Vanderbilt University won a Nobel Prize in Physiology or Medicine in 1971 "for his discoveries concerning the mechanisms of the action of hormones", especially epinephrine, via second messengers (such as cyclic adenosine monophosphate, cyclic AMP). (wikipedia.org)
  • Erowid.org: Erowid Reference 3068 : Adenosine Cyclic 3',5'-Monophosphate in the Liver Fluke, fasciola hepatica. (erowid.org)
  • In mammals, adenosine 3', 5'-cyclic monophosphate (cAMP) is known to play highly important roles in sperm motility and acrosomal exocytosis. (plos.org)
  • Cyclic AMP (adenosine 3', 5'-cyclic monophosphate) is an important player in sperm function. (plos.org)
  • As in somatic cells, sperm intracellular cAMP concentration is regulated by the opposite action of two enzymes: the adenylyl cyclases (AC), which synthesize cAMP from ATP, and the phosphodiesterases (PDE), which break the phosphodiester bond of cAMP to form 5'-adenosine monophosphate (AMP). (plos.org)
  • Cyclic adenosine monophosphate (cAMP) is one of the most important signaling molecules in virtually all cell types and organisms. (nyu.edu)
  • The objective of this work is to examine the capacity of a mechanical stress to cause changes in cell/substratum and cell/cell interactions via the second messenger cAMP pathway (cyclic Adenosine Monophosphate). (utc.fr)
  • The results demonstrated that two cyclic AMP responsive elements (CREs) in the proximal promoter region of C/EBPβ were involved in the positive regulation of C/EBPβ transcription during granulocyte-macrophage colony-stimulating factor (GM-CSF)-induced differentiation of bone marrow cells. (harvard.edu)
  • Scholars@Duke publication: Regulation of tyrosine hydroxylase mRNA by glucocorticoid and cyclic AMP in a rat pheochromocytoma cell line. (duke.edu)
  • Exposure to 10 -4 M norepinephrine, epinephrine, or isoproterenol elevated intracellular cyclic AMP (cAMP) levels in mesangial cells (25th to 30th passages) nearly threefold. (uthscsa.edu)
  • Endothelin receptor type A signals both the accumulation of inositol phosphates and the inhibition of cyclic AMP generation in rat myometrium: stimulation and desensitization. (aspetjournals.org)
  • 5HT (Calbiochem) caused a marked concentration-dependent accumulation of cyclic AMP especially in 'heads', maximal activation of AC occurring at i mM, and an accompanying increase in motility of the isolated fluke head. (erowid.org)
  • Maxi-mum accumulation of cyclic AMP occurred in 5-10 min. (erowid.org)
  • Cyclic AMP is a ubiquitous secondary message that regulates a large variety of functions. (utmb.edu)
  • Cyclic AMP increased phosphorylation of fluke protein in both fractions. (erowid.org)
  • 2',3'-cGAMP sodium (2'-3'-cyclic GMP-AMP sodium) is a endogenous cGAMP in mammalian cells. (medchemexpress.com)
  • Cyclic GMP-AMP containing mixed phosphodiester linkages is an endogenous high-affinity ligand for STING. (medchemexpress.com)
  • The degree of activation by cyclic AMP was inversely correlated with endogenous cyclic AMP and 5HT concentration. (erowid.org)
  • cGAS recognizes the pathogenic DNA in the cytosol and then synthesizes 2′3′-cyclic GMP-AMP (2′3′cGAMP). (frontiersin.org)
  • Treatment of a subclone of the PC12 pheochromocytoma cell line, PC8b, with either dexamethasone or 8-bromo cyclic AMP resulted in increased translational activity of tyrosine hydroxylase mRNA (mRNATH). (duke.edu)
  • PC8b cells treated with either dexamethasone or 8-bromo cyclic AMP yielded greater mRNATH hybridization on Northern blot analysis and accumulated higher molecular weight tyrosine hydroxylase RNA species. (duke.edu)
  • A novel 17-mer peptide ligand for cyclic AMP was designed using the amino acid sequences of essential subsites in various cyclic AMP-dependent protein kinase (protein kinase A) families. (elsevierpure.com)
  • This indicates that the designed 17-mer peptide actually acted as a selective ligand for cyclic AMP. (elsevierpure.com)
  • Cyclic AMP-Dependent Protein Kinase Type II" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (uchicago.edu)
  • A cyclic AMP-dependent protein kinase subtype primarily found in particulate subcellular fractions. (uchicago.edu)
  • This graph shows the total number of publications written about "Cyclic AMP-Dependent Protein Kinase Type II" by people in this website by year, and whether "Cyclic AMP-Dependent Protein Kinase Type II" was a major or minor topic of these publications. (uchicago.edu)
  • Below are the most recent publications written about "Cyclic AMP-Dependent Protein Kinase Type II" by people in Profiles. (uchicago.edu)
  • In eukaryotes, cyclic AMP works by activating protein kinase A (PKA, or cAMP-dependent protein kinase ). (wikipedia.org)
  • In addition to its PRKA-dependent effects, different studies have clearly demonstrated that cAMP also activates EPAC ( E xchange P roteins directly A ctivated by c AMP) during capacitation and acrosome exocytosis [ 15 - 17 ]. (plos.org)
  • Included under this category are two cyclic-AMP-dependent protein kinase subtypes, each of which is defined by its subunit composition. (rush.edu)
  • The function consequences of mutation in loop 3 of CRP are similar to that of site A and site B in the regulatory subunits of cyclic AMP-dependent protein kinases. (utmb.edu)
  • 2',3'-cGAMP sodium (2'-3'-cyclic GMP-AMP sodium) contains two distinct phosphodiester linkages, one between 2′-OH of GMP and 5′-phosphate of AMP, and the other between 3′-OH of AMP and 5′-phosphate of GMP [1] . (medchemexpress.com)
  • Cyclic AMP response element modulator is a basic leucine zipper transcription factor that is regulated by CYCLIC AMP . (online-medical-dictionary.org)
  • Protein kinase activity was 2-5 times greater in the 'head' than in the posterior end of the fluke and in both particulate and supernatant fractions half-maximal activation was obtained at 0.1-0.4 mcM cyclic AMP. (erowid.org)
  • Incubation of fluke heads for 5 min with 1 mM 5HT increased protein kinase activity of both fractions in the absence of added cyclic AMP, but with 5 mcM cyclic AMP protein kinase activity was increased inthe particulate and decreased in the super-natant fraction. (erowid.org)
  • Kreisberg, JI , Venkatachalam, MA & Patel, PY 1984, ' Cyclic AMP-associated shape change in mesangial cells and its reversal by prostaglandin E 2 ', Kidney international , vol. 25, no. 6, pp. 874-879. (uthscsa.edu)
  • The Au disk electrode, which was modified with the designed 17-mer oligopeptide, responded to cyclic AMP but virtually did not respond to any other cyclic nucleotides using the ion channel sensor mechanism. (elsevierpure.com)
  • The enhanced levels of cyclic AMP were preserved by both caffeine and papaverine, and NaF up to 5 mM caused a specific stimulation of AC. (erowid.org)
  • both strongly stimulated motility but had no effect on cyclic AMP levels. (erowid.org)
  • glucagon (Lilly) and noradrenaline (Winthrop) had no effect on motility or cyclic AMP levels. (erowid.org)
  • 5-Methoxytryptamine (1 mM, Calbiochem) caused a 4-fold increase in motility similar to 5HT but had a much diminished effect on cyclic AMP and AC acitivity, while tryptamine (Calbiochem), 5 - hydroxydimethyltryptamine (Sigma-Chem. (erowid.org)