A specific category of drugs that prevent sleepiness by specifically targeting sleep-mechanisms in the brain. They are used to treat DISORDERS OF EXCESSIVE SOMNOLENCE such as NARCOLEPSY. Note that this drug category does not include broadly-acting central nervous system stimulants such as AMPHETAMINES.
A subclass of alpha-adrenergic receptors found on both presynaptic and postsynaptic membranes where they signal through Gi-Go G-PROTEINS. While postsynaptic alpha-2 receptors play a traditional role in mediating the effects of ADRENERGIC AGONISTS, the subset of alpha-2 receptors found on presynaptic membranes signal the feedback inhibition of NEUROTRANSMITTER release.
A ligand that binds to but fails to activate the INTERLEUKIN 1 RECEPTOR. It plays an inhibitory role in the regulation of INFLAMMATION and FEVER. Several isoforms of the protein exist due to multiple ALTERNATIVE SPLICING of its mRNA.
Compounds that inhibit or block the activity of NEUROKININ-1 RECEPTORS.
Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS.
The relationship between the dose of an administered drug and the response of the organism to the drug.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Drugs that selectively bind to but do not activate histamine H2 receptors, thereby blocking the actions of histamine. Their clinically most important action is the inhibition of acid secretion in the treatment of gastrointestinal ulcers. Smooth muscle may also be affected. Some drugs in this class have strong effects in the central nervous system, but these actions are not well understood.
Drugs that bind to but do not activate SEROTONIN 5-HT3 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN 5-HT3 RECEPTOR AGONISTS.
A family of hexahydropyridines.
Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists.
Agents that antagonize ANGIOTENSIN RECEPTORS. Many drugs in this class specifically target the ANGIOTENSIN TYPE 1 RECEPTOR.
Drugs that bind to but do not activate DOPAMINE RECEPTORS, thereby blocking the actions of dopamine or exogenous agonists. Many drugs used in the treatment of psychotic disorders (ANTIPSYCHOTIC AGENTS) are dopamine antagonists, although their therapeutic effects may be due to long-term adjustments of the brain rather than to the acute effects of blocking dopamine receptors. Dopamine antagonists have been used for several other clinical purposes including as ANTIEMETICS, in the treatment of Tourette syndrome, and for hiccup. Dopamine receptor blockade is associated with NEUROLEPTIC MALIGNANT SYNDROME.
Drugs that bind to but do not activate SEROTONIN 5-HT2 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN 5-HT2 RECEPTOR AGONISTS. Included under this heading are antagonists for one or more specific 5-HT2 receptor subtypes.
Compounds that selectively bind to and block the activation of ADENOSINE A2 RECEPTORS.
Chemical substances which inhibit the function of the endocrine glands, the biosynthesis of their secreted hormones, or the action of hormones upon their specific sites.
Compounds that bind to and block the stimulation of ADENOSINE A1 RECEPTORS.
Compounds that bind to and block the stimulation of PURINERGIC P2 RECEPTORS.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Agents inhibiting the effect of narcotics on the central nervous system.
Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood.
Cell surface proteins that bind ENDOTHELINS with high affinity and trigger intracellular changes which influence the behavior of cells.
Drugs that bind to but do not activate MUSCARINIC RECEPTORS, thereby blocking the actions of endogenous ACETYLCHOLINE or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system.
Drugs that bind to but do not activate GABA-A RECEPTORS thereby blocking the actions of endogenous or exogenous GABA-A RECEPTOR AGONISTS.
Drugs that bind to and block the activation of ADRENERGIC ALPHA-1 RECEPTORS.
Drugs that bind to but do not activate serotonin receptors, thereby blocking the actions of serotonin or SEROTONIN RECEPTOR AGONISTS.
Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.
Glycoproteins which contain sialic acid as one of their carbohydrates. They are often found on or in the cell or tissue membranes and participate in a variety of biological activities.
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.
One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.
Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES.
A class of drugs designed to prevent leukotriene synthesis or activity by blocking binding at the receptor level.
A subtype of endothelin receptor found predominantly in the VASCULAR SMOOTH MUSCLE. It has a high affinity for ENDOTHELIN-1 and ENDOTHELIN-2.
Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.
A class of ionotropic glutamate receptors characterized by affinity for N-methyl-D-aspartate. NMDA receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity.
Drugs that bind to but do not activate SEROTONIN 5-HT1 RECEPTORS, thereby blocking the actions of SEROTONIN 5-HT1 RECEPTOR AGONISTS. Included under this heading are antagonists for one or more of the specific 5-HT1 receptor subtypes.
Drugs that bind to nicotinic cholinergic receptors (RECEPTORS, NICOTINIC) and block the actions of acetylcholine or cholinergic agonists. Nicotinic antagonists block synaptic transmission at autonomic ganglia, the skeletal neuromuscular junction, and at central nervous system nicotinic synapses.
A potent noncompetitive antagonist of the NMDA receptor (RECEPTORS, N-METHYL-D-ASPARTATE) used mainly as a research tool. The drug has been considered for the wide variety of neurodegenerative conditions or disorders in which NMDA receptors may play an important role. Its use has been primarily limited to animal and tissue experiments because of its psychotropic effects.
Cell surface receptors that are specific for INTERLEUKIN-1. Included under this heading are signaling receptors, non-signaling receptors and accessory proteins required for receptor signaling. Signaling from interleukin-1 receptors occurs via interaction with SIGNAL TRANSDUCING ADAPTOR PROTEINS such as MYELOID DIFFERENTIATION FACTOR 88.
Drugs that bind to and block the activation of ADRENERGIC ALPHA-2 RECEPTORS.
Drugs that bind to but do not activate alpha-adrenergic receptors thereby blocking the actions of endogenous or exogenous adrenergic agonists. Adrenergic alpha-antagonists are used in the treatment of hypertension, vasospasm, peripheral vascular disease, shock, and pheochromocytoma.
Biphenyl compounds are organic substances consisting of two phenyl rings connected by a single covalent bond, and can exhibit various properties and uses, including as intermediates in chemical synthesis, components in plastics and dyes, and as additives in fuels.
Compounds with BENZENE fused to AZEPINES.
Tetrazoles are heterocyclic organic compounds containing a 1,3,5-triazole ring with an additional nitrogen atom, often used in pharmaceuticals as bioisosteres for carboxylic acid groups due to their isoelectronic nature and similar hydrogen bonding capabilities.
Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).
Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
Purine bases found in body tissues and fluids and in some plants.
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.
Endogenous compounds and drugs that bind to and activate SEROTONIN RECEPTORS. Many serotonin receptor agonists are used as ANTIDEPRESSANTS; ANXIOLYTICS; and in the treatment of MIGRAINE DISORDERS.
Peptides whose amino and carboxy ends are linked together with a peptide bond forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS. Some of them are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).
A group of compounds that contain the structure SO2NH2.
The action of a drug that may affect the activity, metabolism, or toxicity of another drug.
Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
Drugs that selectively bind to but do not activate HISTAMINE H3 RECEPTORS. They have been used to correct SLEEP WAKE DISORDERS and MEMORY DISORDERS.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
Azoles of two nitrogens at the 1,2 positions, next to each other, in contrast with IMIDAZOLES in which they are at the 1,3 positions.
Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.
Quinoxalines are heterocyclic organic compounds consisting of a benzene fused to a pyrazine ring, which have been studied for their potential antibacterial, antifungal, and anticancer properties.
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.
Seven membered heterocyclic rings containing a NITROGEN atom.
Elements of limited time intervals, contributing to particular results or situations.
An antagonist of ANGIOTENSIN TYPE 1 RECEPTOR with antihypertensive activity due to the reduced pressor effect of ANGIOTENSIN II.
A 21-amino acid peptide produced in a variety of tissues including endothelial and vascular smooth-muscle cells, neurons and astrocytes in the central nervous system, and endometrial cells. It acts as a modulator of vasomotor tone, cell proliferation, and hormone production. (N Eng J Med 1995;333(6):356-63)
Drugs that bind to but do not activate GABA-B RECEPTORS thereby blocking the actions of endogenous or exogenous GABA-B RECEPTOR AGONISTS.
An eleven-amino acid neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of PAIN, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses.
A member of the NICOTINIC ACETYLCHOLINE RECEPTOR subfamily of the LIGAND-GATED ION CHANNEL family. It consists entirely of pentameric a7 subunits expressed in the CNS, autonomic nervous system, vascular system, lymphocytes and spleen.
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.
Cell surface receptors that bind BRADYKININ and related KININS with high affinity and trigger intracellular changes which influence the behavior of cells. The identified receptor types (B-1 and B-2, or BK-1 and BK-2) recognize endogenous KALLIDIN; t-kinins; and certain bradykinin fragments as well as bradykinin itself.
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.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
A histamine congener, it competitively inhibits HISTAMINE binding to HISTAMINE H2 RECEPTORS. Cimetidine has a range of pharmacological actions. It inhibits GASTRIC ACID secretion, as well as PEPSIN and GASTRIN output.
A class of cell surface receptors for TACHYKININS with a preference for SUBSTANCE P. Neurokinin-1 (NK-1) receptors have been cloned and are members of the G protein coupled receptor superfamily. They are found on many cell types including central and peripheral neurons, smooth muscle cells, acinar cells, endothelial cells, fibroblasts, and immune cells.
Compounds that selectively bind to and block the activation of ADENOSINE A3 RECEPTORS.
A subtype of endothelin receptor found predominantly in the KIDNEY. It may play a role in reducing systemic ENDOTHELIN levels.
Compounds that bind to and block the stimulation of PURINERGIC P2X RECEPTORS. Included under this heading are antagonists for specific P2X receptor subtypes.
Piperazines are a class of heterocyclic organic compounds containing a seven-membered ring with two nitrogen atoms at positions 1 and 4, often used in pharmaceuticals as smooth muscle relaxants, antipsychotics, antidepressants, and antihistamines, but can also be found as recreational drugs with stimulant and entactogen properties.
The observable response an animal makes to any situation.
Pyrrolidines are saturated, heterocyclic organic compounds containing a five-membered ring with four carbon atoms and one nitrogen atom (NRCH2CH2), commonly found as structural components in various alkaloids and used in the synthesis of pharmaceuticals and other organic materials.
A subclass of alpha-adrenergic receptors that mediate contraction of SMOOTH MUSCLE in a variety of tissues such as ARTERIOLES; VEINS; and the UTERUS. They are usually found on postsynaptic membranes and signal through GQ-G11 G-PROTEINS.
A soluble factor produced by MONOCYTES; MACROPHAGES, and other cells which activates T-lymphocytes and potentiates their response to mitogens or antigens. Interleukin-1 is a general term refers to either of the two distinct proteins, INTERLEUKIN-1ALPHA and INTERLEUKIN-1BETA. The biological effects of IL-1 include the ability to replace macrophage requirements for T-cell activation.
Cell surface proteins that bind cholecystokinin (CCK) with high affinity and trigger intracellular changes influencing the behavior of cells. Cholecystokinin receptors are activated by GASTRIN as well as by CCK-4; CCK-8; and CCK-33. Activation of these receptors evokes secretion of AMYLASE by pancreatic acinar cells, acid and PEPSIN by stomach mucosal cells, and contraction of the PYLORUS and GALLBLADDER. The role of the widespread CCK receptors in the central nervous system is not well understood.
A derivative of benzodiazepine that acts on the cholecystokinin A (CCKA) receptor to antagonize CCK-8's (SINCALIDE) physiological and behavioral effects, such as pancreatic stimulation and inhibition of feeding.
Drugs that bind to but do not activate ADRENERGIC RECEPTORS. Adrenergic antagonists block the actions of the endogenous adrenergic transmitters EPINEPHRINE and NOREPINEPHRINE.
A selective adrenergic alpha-1 antagonist used in the treatment of HEART FAILURE; HYPERTENSION; PHEOCHROMOCYTOMA; RAYNAUD DISEASE; PROSTATIC HYPERTROPHY; and URINARY RETENTION.
Cell surface proteins that bind THROMBOXANES with high affinity and trigger intracellular changes influencing the behavior of cells. Some thromboxane receptors act via the inositol phosphate and diacylglycerol second messenger systems.
Specific molecular sites or proteins on or in cells to which VASOPRESSINS bind or interact in order to modify the function of the cells. Two types of vasopressin receptor exist, the V1 receptor in the vascular smooth muscle and the V2 receptor in the kidneys. The V1 receptor can be subdivided into V1a and V1b (formerly V3) receptors.
A selective serotonin receptor antagonist with weak adrenergic receptor blocking properties. The drug is effective in lowering blood pressure in essential hypertension. It also inhibits platelet aggregation. It is well tolerated and is particularly effective in older patients.
The D-enantiomer is a potent and specific antagonist of NMDA glutamate receptors (RECEPTORS, N-METHYL-D-ASPARTATE). The L form is inactive at NMDA receptors but may affect the AP4 (2-amino-4-phosphonobutyrate; APB) excitatory amino acid receptors.
Drugs that bind to but do not activate SEROTONIN 5-HT4 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN RECEPTOR AGONISTS.
Use of electric potential or currents to elicit biological responses.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
A subclass of cannabinoid receptor found primarily on central and peripheral NEURONS where it may play a role modulating NEUROTRANSMITTER release.
Compounds with a BENZENE fused to IMIDAZOLES.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D2-class receptor genes contain INTRONS, and the receptors inhibit ADENYLYL CYCLASES.
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.
Derivative of noroxymorphone that is the N-cyclopropylmethyl congener of NALOXONE. It is a narcotic antagonist that is effective orally, longer lasting and more potent than naloxone, and has been proposed for the treatment of heroin addiction. The FDA has approved naltrexone for the treatment of alcohol dependence.
Injections into the cerebral ventricles.
Drugs that selectively bind to and activate alpha adrenergic receptors.
A competitive histamine H2-receptor antagonist. Its main pharmacodynamic effect is the inhibition of gastric secretion.
A class of cell surface receptors for tachykinins that prefers neurokinin A; (NKA, substance K, neurokinin alpha, neuromedin L), neuropeptide K; (NPK); or neuropeptide gamma over other tachykinins. Neurokinin-2 (NK-2) receptors have been cloned and are similar to other G-protein coupled receptors.
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.
A nonapeptide messenger that is enzymatically produced from KALLIDIN in the blood where it is a potent but short-lived agent of arteriolar dilation and increased capillary permeability. Bradykinin is also released from MAST CELLS during asthma attacks, from gut walls as a gastrointestinal vasodilator, from damaged tissues as a pain signal, and may be a neurotransmitter.
Compounds that inhibit or block the activity of CANNABINOID RECEPTORS.
A specific opiate antagonist that has no agonist activity. It is a competitive antagonist at mu, delta, and kappa opioid receptors.
Quinuclidines are organic compounds consisting of a tricyclic structure with a three-membered ring fused to a piperidine ring, often used as building blocks in the synthesis of pharmaceuticals and bioactive molecules.
Benzodiazepinones are a class of psychoactive drugs that bind to the GABA-A receptor and enhance its inhibitory effects, producing anxiolytic, sedative, hypnotic, anticonvulsant, and muscle relaxant properties.
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.
Drugs that bind to and block the activation of ADRENERGIC BETA-2 RECEPTORS.
An isoquinoline alkaloid obtained from Dicentra cucullaria and other plants. It is a competitive antagonist for GABA-A receptors.
One of the two major classes of cholinergic receptors. Nicotinic receptors were originally distinguished by their preference for NICOTINE over MUSCARINE. They are generally divided into muscle-type and neuronal-type (previously ganglionic) based on pharmacology, and subunit composition of the receptors.
Compounds containing 1,3-diazole, a five membered aromatic ring containing two nitrogen atoms separated by one of the carbons. Chemically reduced ones include IMIDAZOLINES and IMIDAZOLIDINES. Distinguish from 1,2-diazole (PYRAZOLES).
An interleukin-1 subtype that occurs as a membrane-bound pro-protein form that is cleaved by proteases to form a secreted mature form. Unlike INTERLEUKIN-1BETA both membrane-bound and secreted forms of interleukin-1alpha are biologically active.
Drugs that bind to and block the activation of MINERALOCORTICOID RECEPTORS by MINERALOCORTICOIDS such as ALDOSTERONE.
A class of histamine receptors discriminated by their pharmacology and mode of action. Histamine H3 receptors were first recognized as inhibitory autoreceptors on histamine-containing nerve terminals and have since been shown to regulate the release of several neurotransmitters in the central and peripheral nervous systems. (From Biochem Soc Trans 1992 Feb;20(1):122-5)
PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
A plant alkaloid with alpha-2-adrenergic blocking activity. Yohimbine has been used as a mydriatic and in the treatment of ERECTILE DYSFUNCTION.
Cell membrane proteins that bind opioids and trigger intracellular changes which influence the behavior of cells. The endogenous ligands for opioid receptors in mammals include three families of peptides, the enkephalins, endorphins, and dynorphins. The receptor classes include mu, delta, and kappa receptors. Sigma receptors bind several psychoactive substances, including certain opioids, but their endogenous ligands are not known.

alpha1-adrenergic receptor subtypes in human peripheral blood lymphocytes. (1/356)

We investigated the expression of alpha1-adrenergic receptor subtypes in intact human peripheral blood lymphocytes using reverse transcription-polymerase chain reaction (RT-PCR) and radioligand binding assay techniques combined with antibodies against the three subtypes of alpha1-adrenergic receptors (alpha1A, alpha1B, and alpha1D). RT-PCR amplified in peripheral blood lymphocytes a 348-bp alpha1A-adrenergic receptor fragment, a 689-bp alpha1B-adrenergic receptor fragment, and a 540-bp alpha1D-adrenergic receptor fragment. Radioligand binding assay with [3H]prazosin as radioligand revealed a high-affinity binding with a dissociation constant value of 0. 65+/-0.05 nmol/L and a maximum density of binding sites of 175. 3+/-20.5 fmol/10(6) cells. The pharmacological profile of [3H]prazosin binding to human peripheral blood lymphocytes was consistent with the labeling of alpha1-adrenergic receptors. Antibodies against alpha1A-, alpha1B-, and alpha1D-receptor subtypes decreased [3H]prazosin binding to a different extent. This indicates that human peripheral blood lymphocytes express the three alpha1-adrenergic receptor subtypes. Of the three different alpha1-adrenergic receptor subtypes, the alpha1B is the most represented and the alpha1D, the least. Future studies should clarify the functional relevance of alpha1-adrenergic receptors expressed by peripheral blood lymphocytes. The identification of these sites may represent a step for evaluating whether they represent a marker of alpha1-adrenergic receptors in cardiovascular disorders or for assessing responses to drug treatment on these receptors.  (+info)

Modulation of basal intracellular calcium by inverse agonists and phorbol myristate acetate in rat-1 fibroblasts stably expressing alpha1d-adrenoceptors. (2/356)

In rat-1 fibroblasts stably expressing alpha1d-adrenoceptors BMY 7378, phentolamine, chloroethylclonidine and 5-methyl urapidil decreased basal [Ca2+]i. WB 4101 induced a very small effect on this parameter but when added before the other antagonists it blocked their effect. All these agents inhibited the action of norepinephrine. Phorbol myristate acetate also blocked the effect of norepinephrine and decreased basal [Ca2+]i. Staurosporine inhibited these effects of the phorbol ester. Our results suggest that: (1) alpha1d-adrenoceptors exhibit spontaneous ligand-independent activity, (2) BMY 7378, phentolamine, chloroethylclonidine and 5-methyl urapidil act as inverse agonists and (3) protein kinase C activation blocks spontaneous and agonist-stimulated alpha1d-adrenoceptor activity.  (+info)

Characterization of alpha1-adrenoceptor subtypes mediating vasoconstriction in human umbilical vein. (3/356)

1. The present study attempted to characterize pharmacologically the subtypes of alpha-adrenoceptors mediating contractions in human umbilical vein (HUV). 2. HUV rings were mounted in isolated organ baths and cumulative concentration-response curves were constructed for the alpha-adrenoceptor agonists phenylephrine and adrenaline. Adrenaline was more potent than phenylephrine (pD2=7.29 and 6.04 respectively). 3. Isoproterenol exhibited no agonism on KCl pre-contracted HUV rings. Propranolol (1 microM) and rauwolscine (0.1 microM) did not affect the concentration-response curves to adrenaline. These results demonstrate the lack of involvement of functional beta-or alpha2-adrenoceptors in adrenaline-induced vasoconstriction. 4. The non subtype selective alpha1-adrenoceptor antagonist prazosin was evaluated on phenylephrine and adrenaline concentration-response curves. The effects of the competitive alpha1A and alpha1D-adrenoceptor antagonists, 5-methyl urapidil and BMY 7378 and the irreversible alpha1B selective compound chloroethylclonidine (CEC) were also evaluated on adrenaline concentration-response curves. 5. The potencies of prazosin against responses mediated by adrenaline (pA2= 10.87) and phenylephrine (pA2= 10.70) indicate the involvement of prazosin-sensitive functional alpha1-adrenoceptor subtype in vasoconstriction of the HUV. 6. The potencies of 5-methyl urapidil (pA2 = 6.70) and BMY 7378 (pA2= 7.34) were not consistent with the activation of an alpha1A- or alpha1D-adrenoceptor population. 7. Exposure to a relatively low CEC concentration (3 microM) abolished the maximum response to adrenaline suggesting that this response was mediated by an alpha1B-adrenoceptor subtype. 8. We conclude that HUV express a prazosin-sensitive functional alpha1-adrenoceptor resembling the alpha1B-subtype according with the low pA2 values for both 5-methyl urapidil and BMY 7378 and the high sensitivity to CEC.  (+info)

Comparison of relaxation responses of cavernous and trigonal smooth muscles from rabbits by alpha1-adrenoceptor antagonists; prazosin, terazosin, doxazosin, and tamsulosin. (4/356)

Alpha1a-adrenergic receptor (AR) primarily mediates the contraction of the prostatic and cavernous smooth muscles. Among clinically available alpha1-AR antagonists for the medical management of benign prostatic hyperplasia (BPH), tamsulosin has a modest selectivity for alpha1A- and alpha1D- over alpha1B-ARs. To compare the effects of various alpha1-AR antagonists on relaxation responses of cavernous and trigonal smooth muscles, isometric tension studies with relatively selective (tamsulosin) and non-selective (prazosin, doxazosin, and terazosin) alpha1A-AR antagonists, were conducted in the cavernous and trigonal muscle strips of rabbits (n=10 each). Tamsulosin had the strongest inhibitory effect on contraction of trigonal smooth muscle among the various alpha1-AR antagonists, and the inhibitory activities of prazosin, doxazosin, and terazosin were not statistically different. All alpha1-AR antagonists caused concentration-dependent relaxation of the cavernous muscle strips. Tamsulosin was shown to have greater potency than prazosin (more than 100-fold), doxazosin (more than 1000-fold), and terazosin (more than 1000-fold), in relaxation of cavernous smooth muscle. In conclusion, tamsulosin might be the most effective drug among the four commonly used alpha1-AR antagonists for the medical management of BPH. Tamsulosin might be a potential substitute for phentolamine in combination with vasoactive agents as an intracavernous injection therapy for patients with erectile dysfunction.  (+info)

Canine external carotid vasoconstriction to methysergide, ergotamine and dihydroergotamine: role of 5-HT1B/1D receptors and alpha2-adrenoceptors. (5/356)

The antimigraine drugs methysergide, ergotamine and dihydroergotamine (DHE) produce selective vasoconstriction in the external carotid bed of vagosympathectomized dogs anaesthetized with pentobarbital and artificially respired, but the receptors involved have not yet been completely characterized. Since the above drugs display affinity for several binding sites, including alpha-adrenoceptors and several 5-HT1 and 5-HT2 receptor subtypes, this study has analysed the mechanisms involved in the above responses. Intracarotid (i.c.) infusions during 1 min of methysergide (31-310 microg min(-1)), ergotamine (0.56-5.6 microg min(-1)) or DHE (5.6-31 microg min(-1)) dose-dependently reduced external carotid blood flow (ECBF) by up to 46+/-4, 37+/-4 and 49+/-5%, respectively. Blood pressure and heart rate remained unchanged. The reductions in ECBF by methysergide were abolished and even reversed to increases in animals pre-treated with GR127935 (10 microg kg(-1), i.v.). The reductions in ECBF by ergotamine and DHE remained unchanged in animals pre-treated (i.v.) with prazosin (300 microg kg(-1)), but were partly antagonized in animals pre-treated with either GR127935 (10 or 30 microg kg(-1)) or yohimbine (1000 microg kg(-1)). Pre-treatment with a combination of GR127935 (30 microg kg(-1)) and yohimbine (1000 microg kg(-1)) abolished the responses to both ergotamine and DHE. The above doses of antagonists were shown to produce selective antagonism at their respective receptors. These results suggest that the external carotid vasoconstrictor responses to methysergide primarily involve 5-HT1B/1D receptors, whereas those to ergotamine and DHE are mediated by 5-HT1B/1D receptors as well as alpha2-adrenoceptors.  (+info)

alpha1-adrenergic receptor activation of c-fos expression in transfected rat-1 fibroblasts: role of Ca2+. (6/356)

alpha1-Adrenergic receptors mediate mitogenic responses and increase intracellular free Ca2+ ([Ca2+]i) in vascular smooth muscle cells. Induction of c-fos is a critical early event in cell growth; expression of this gene is regulated by a number of signaling pathways including Ca2+. We wondered whether Ca2+ signaling plays a critical role in the induction of c-fos gene by alpha1-adrenergic receptors. Using stably transfected rat-1 fibroblasts, we confirmed that PE induced c-fos mRNA expression in a time- and dose-dependent manner, and also increased [Ca2+]i (measured with Fura-2 AM). These responses were blocked by the alpha1-adrenergic receptor antagonist doxazosin. Both intracellular Ca2+ chelation (using BAPTA/AM) and extracellular Ca2+ depletion (using EGTA) significantly inhibited PE-induced c-fos expression by alpha1A and alpha1B receptors. Brief (1-min) stimulation of alpha1A and alpha1B receptors with PE did not maximally induce c-fos expression, suggesting that a sustained increase in [Ca2+]i due to Ca2+ influx is required. The calmodulin (CaM) antagonists, R24571, W7, and trifluoperazine, but not the CaM-dependent protein kinases inhibitor KN-62, significantly inhibited c-fos induction by alpha1A and alpha1B receptors. Neither inhibition of protein kinase C nor inhibition of adenylyl cyclase modified c-fos induction by PE. These results suggest that alpha1-adrenergic receptor-induced c-fos expression in rat-1 cells is dependent on a Ca2+/CaM-associated pathway.  (+info)

In vivo measurement by [3H]Tamsulosin of alpha1 adrenoceptors in rat tissues in relation to the pharmacokinetics. (7/356)

The present study was undertaken to simultaneously measure alpha1 adrenoceptors in rat tissues by [3H]tamsulosin in vivo. In vivo specific [3H]tamsulosin binding was observed in the prostate, vas deferens, aorta, submaxillary gland, spleen, heart, lung, and kidney after i.v. injection of the ligand but not in the cerebral cortex and liver. Specific [3H]tamsulosin binding in the kidney, lung, heart, and spleen was greatest at 3 min after i.v. injection and declined rapidly with the disappearance of [3H]tamsulosin from the plasma. On the other hand, [3H]tamsulosin binding in the prostate and aorta peaked at 10 to 60 min after i.v. injection, and a considerable level of specific binding in both tissues persisted up to 240 min. The most sustained binding of [3H]tamsulosin occurred in the submaxillary gland. In vivo specific [3H]tamsulosin binding in rat tissues was effectively inhibited by the coinjection of low doses of unlabeled tamsulosin, prazosin, and terazosin with the radioligand but not by relatively high doses of yohimbine and propranolol. Based on estimated ID50 values, in vivo inhibitory effect of tamsulosin compared with prazosin was 5 to 14 times greater in rat tissues except the spleen, which showed 1.6 times less potent than prazosin. From ratios of ID50 (spleen) to ID50 (submaxillary gland) or ID50 (prostate), tamsulosin was 9 and 19 times, respectively, greater than prazosin in selectivity of alpha1 adrenoceptors in the submaxillary gland and prostate versus the spleen, respectively, suggesting that tamsulosin binds to alpha1A subtype with higher affinity than alpha1B subtype in vivo. The present study suggests that [3H]tamsulosin is a useful radioligand for in vivo measurement of alpha1 adrenoceptors in rat tissues.  (+info)

Naftopidil, a novel alpha1-adrenoceptor antagonist, displays selective inhibition of canine prostatic pressure and high affinity binding to cloned human alpha1-adrenoceptors. (8/356)

The pharmacological profiles of the alpha1-adrenoceptor antagonists naftopidil, tamsulosin and prazosin were studied in an anesthetized dog model that allowed the simultaneous assessment of their antagonist potency against phenylephrine-mediated increases in prostatic pressure and mean blood pressure. The intravenous administration of each of these compounds dose-dependently inhibited phenylephrine-induced increases in prostatic pressure and mean blood pressure. To further assess the ability of the three compounds to inhibit phenylephrine-induced responses, the doses required to produce a 50% inhibition of the phenylephrine-induced increases in prostatic and mean blood pressure and the selectivity index obtained from the ratio of those two doses were determined for each test compound. Forty minutes after the intravenous administration of naftopidil, the selectivity index was 3.76, and those of tamsulosin and prazosin were 1.23 and 0.61, respectively. These findings demonstrated that naftopidil selectively inhibited the phenylephrine-induced increase in prostatic pressure compared with mean blood pressure in the anesthetized dog model. The selectivity of naftopidil for prostatic pressure was the most potent among the test compounds. In addition, using cloned human alpha1-adrenoceptor subtypes, naftopidil was selective for the alpha1d-adrenoceptor with approximately 3- and 17-fold higher affinity than for the alpha1a- and alpha1b-adrenoceptor subtypes, respectively. The selectivity of naftopidil for prostatic pressure may be attributable to its high binding affinity for alpha1a- and alpha1d-adrenoceptor subtypes.  (+info)

Wakefulness-promoting agents are a class of medications that are used to promote and maintain alertness and wakefulness. They work by stimulating the brain's arousal centers, increasing the release of neurotransmitters such as dopamine, norepinephrine, and histamine, which help to counteract the effects of sleep-promoting substances in the brain.

Wakefulness-promoting agents are typically used to treat excessive daytime sleepiness associated with conditions such as narcolepsy, obstructive sleep apnea, shift work sleep disorder, and other disorders that cause disrupted sleep patterns. Some examples of wakefulness-promoting agents include modafinil, armodafinil, pitolisant, and solriamfetol.

It is important to note that while these medications can help to promote alertness and reduce excessive daytime sleepiness, they are not a substitute for getting adequate amounts of quality sleep. It is also important to use them under the guidance of a healthcare provider, as they may have potential side effects and interactions with other medications.

Alpha-2 adrenergic receptors are a type of G protein-coupled receptor that binds catecholamines, such as norepinephrine and epinephrine. These receptors are widely distributed in the central and peripheral nervous system, as well as in various organs and tissues throughout the body.

Activation of alpha-2 adrenergic receptors leads to a variety of physiological responses, including inhibition of neurotransmitter release, vasoconstriction, and reduced heart rate. These receptors play important roles in regulating blood pressure, pain perception, and various cognitive and emotional processes.

There are several subtypes of alpha-2 adrenergic receptors, including alpha-2A, alpha-2B, and alpha-2C, which may have distinct physiological functions and be targeted by different drugs. For example, certain medications used to treat hypertension or opioid withdrawal target alpha-2 adrenergic receptors to produce their therapeutic effects.

Interleukin-1 Receptor Antagonist Protein (IL-1Ra) is a naturally occurring protein that acts as a competitive inhibitor of the interleukin-1 (IL-1) receptor. IL-1 is a pro-inflammatory cytokine involved in various physiological processes, including the immune response and inflammation. The binding of IL-1 to its receptor triggers a signaling cascade that leads to the activation of inflammatory genes and cellular responses.

IL-1Ra shares structural similarities with IL-1 but does not initiate the downstream signaling pathway. Instead, it binds to the same receptor site as IL-1, preventing IL-1 from interacting with its receptor and thus inhibiting the inflammatory response.

Increased levels of IL-1Ra have been found in various inflammatory conditions, such as rheumatoid arthritis, inflammatory bowel disease, and sepsis, where it acts to counterbalance the pro-inflammatory effects of IL-1. Recombinant IL-1Ra (Anakinra) is used clinically as a therapeutic agent for the treatment of rheumatoid arthritis and other inflammatory diseases.

Neurokinin-1 (NK-1) receptor antagonists are a class of drugs that block the action of substance P, a neuropeptide involved in pain transmission and inflammation. These drugs work by binding to NK-1 receptors found on nerve cells, preventing substance P from activating them and transmitting pain signals. NK-1 receptor antagonists have been studied for their potential use in treating various conditions associated with pain and inflammation, such as migraine headaches, depression, and irritable bowel syndrome. Some examples of NK-1 receptor antagonists include aprepitant, fosaprepitant, and rolapitant.

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.

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.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

Histamine H2 antagonists, also known as H2 blockers, are a class of medications that work by blocking the action of histamine on the H2 receptors in the stomach. Histamine is a chemical that is released by the body during an allergic reaction and can also be released by certain cells in the stomach in response to food or other stimuli. When histamine binds to the H2 receptors in the stomach, it triggers the release of acid. By blocking the action of histamine on these receptors, H2 antagonists reduce the amount of acid produced by the stomach, which can help to relieve symptoms such as heartburn, indigestion, and stomach ulcers. Examples of H2 antagonists include ranitidine (Zantac), famotidine (Pepcid), and cimetidine (Tagamet).

Serotonin 5-HT3 receptor antagonists are a class of medications that work by blocking the serotonin 5-HT3 receptors, which are found in the gastrointestinal tract and the brain. These receptors play a role in regulating nausea and vomiting, among other functions.

When serotonin binds to these receptors, it can trigger a series of events that lead to nausea and vomiting, particularly in response to chemotherapy or surgery. By blocking the 5-HT3 receptors, serotonin cannot bind to them and therefore cannot trigger these events, which helps to reduce nausea and vomiting.

Examples of 5-HT3 receptor antagonists include ondansetron (Zofran), granisetron (Kytril), palonosetron (Aloxi), and dolasetron (Anzemet). These medications are commonly used to prevent and treat nausea and vomiting associated with chemotherapy, radiation therapy, and surgery.

Piperidines are not a medical term per se, but they are a class of organic compounds that have important applications in the pharmaceutical industry. Medically relevant piperidines include various drugs such as some antihistamines, antidepressants, and muscle relaxants.

A piperidine is a heterocyclic amine with a six-membered ring containing five carbon atoms and one nitrogen atom. The structure can be described as a cyclic secondary amine. Piperidines are found in some natural alkaloids, such as those derived from the pepper plant (Piper nigrum), which gives piperidines their name.

In a medical context, it is more common to encounter specific drugs that belong to the class of piperidines rather than the term itself.

Excitatory amino acid antagonists are a class of drugs that block the action of excitatory neurotransmitters, particularly glutamate and aspartate, in the brain. These drugs work by binding to and blocking the receptors for these neurotransmitters, thereby reducing their ability to stimulate neurons and produce an excitatory response.

Excitatory amino acid antagonists have been studied for their potential therapeutic benefits in a variety of neurological conditions, including stroke, epilepsy, traumatic brain injury, and neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, their use is limited by the fact that blocking excitatory neurotransmission can also have negative effects on cognitive function and memory.

There are several types of excitatory amino acid receptors, including N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and kainite receptors. Different excitatory amino acid antagonists may target one or more of these receptor subtypes, depending on their specific mechanism of action.

Examples of excitatory amino acid antagonists include ketamine, memantine, and dextromethorphan. These drugs have been used in clinical practice for various indications, such as anesthesia, sedation, and treatment of neurological disorders. However, their use must be carefully monitored due to potential side effects and risks associated with blocking excitatory neurotransmission.

Angiotensin receptor antagonists (ARAs), also known as angiotensin II receptor blockers (ARBs), are a class of medications used to treat hypertension, heart failure, and protect against kidney damage in patients with diabetes. They work by blocking the action of angiotensin II, a potent vasoconstrictor and hormone that increases blood pressure and promotes tissue fibrosis. By blocking the binding of angiotensin II to its receptors, ARAs cause relaxation of blood vessels, decreased sodium and water retention, and reduced cardiac remodeling, ultimately leading to improved cardiovascular function and reduced risk of organ damage. Examples of ARAs include losartan, valsartan, irbesartan, and candesartan.

Dopamine antagonists are a class of drugs that block the action of dopamine, a neurotransmitter in the brain associated with various functions including movement, motivation, and emotion. These drugs work by binding to dopamine receptors and preventing dopamine from attaching to them, which can help to reduce the symptoms of certain medical conditions such as schizophrenia, bipolar disorder, and gastroesophageal reflux disease (GERD).

There are several types of dopamine antagonists, including:

1. Typical antipsychotics: These drugs are primarily used to treat psychosis, including schizophrenia and delusional disorders. Examples include haloperidol, chlorpromazine, and fluphenazine.
2. Atypical antipsychotics: These drugs are also used to treat psychosis but have fewer side effects than typical antipsychotics. They may also be used to treat bipolar disorder and depression. Examples include risperidone, olanzapine, and quetiapine.
3. Antiemetics: These drugs are used to treat nausea and vomiting. Examples include metoclopramide and prochlorperazine.
4. Dopamine agonists: While not technically dopamine antagonists, these drugs work by stimulating dopamine receptors and can be used to treat conditions such as Parkinson's disease. However, they can also have the opposite effect and block dopamine receptors in high doses, making them functionally similar to dopamine antagonists.

Common side effects of dopamine antagonists include sedation, weight gain, and movement disorders such as tardive dyskinesia. It's important to use these drugs under the close supervision of a healthcare provider to monitor for side effects and adjust the dosage as needed.

Serotonin 5-HT2 receptor antagonists are a class of drugs that block the action of serotonin, a neurotransmitter, at 5-HT2 receptors. These receptors are found in the central and peripheral nervous systems and are involved in various physiological functions such as mood regulation, cognition, appetite control, and vasoconstriction.

By blocking the action of serotonin at these receptors, serotonin 5-HT2 receptor antagonists can produce a range of effects depending on the specific receptor subtype that they target. For example, some serotonin 5-HT2 receptor antagonists are used to treat psychiatric disorders such as schizophrenia and depression, while others are used to treat migraines or prevent nausea and vomiting associated with chemotherapy.

Some common examples of serotonin 5-HT2 receptor antagonists include risperidone, olanzapine, and paliperidone (used for the treatment of schizophrenia), mirtazapine (used for the treatment of depression), sumatriptan (used for the treatment of migraines), and ondansetron (used to prevent nausea and vomiting).

Adenosine A2 receptor antagonists are a class of pharmaceutical compounds that block the action of adenosine at A2 receptors. Adenosine is a naturally occurring molecule in the body that acts as a neurotransmitter and has various physiological effects, including vasodilation and inhibition of heart rate.

Adenosine A2 receptor antagonists work by binding to A2 receptors and preventing adenosine from activating them. This results in the opposite effect of adenosine, leading to vasoconstriction and increased heart rate. These drugs are used for a variety of medical conditions, including asthma, chronic obstructive pulmonary disease (COPD), and heart failure.

Examples of Adenosine A2 receptor antagonists include theophylline, caffeine, and some newer drugs such asistradefylline and tozadenant. These drugs have different pharmacological properties and are used for specific medical conditions. It is important to note that adenosine A2 receptor antagonists can have side effects, including restlessness, insomnia, and gastrointestinal symptoms, and should be used under the guidance of a healthcare professional.

Hormone antagonists are substances or drugs that block the action of hormones by binding to their receptors without activating them, thereby preventing the hormones from exerting their effects. They can be classified into two types: receptor antagonists and enzyme inhibitors. Receptor antagonists bind directly to hormone receptors and prevent the hormone from binding, while enzyme inhibitors block the production or breakdown of hormones by inhibiting specific enzymes involved in their metabolism. Hormone antagonists are used in the treatment of various medical conditions, such as cancer, hormonal disorders, and cardiovascular diseases.

Adenosine A1 receptor antagonists are a class of pharmaceutical compounds that block the action of adenosine at A1 receptors. Adenosine is a naturally occurring purine nucleoside that acts as a neurotransmitter and modulator of various physiological processes, including cardiovascular function, neuronal excitability, and immune response.

Adenosine exerts its effects by binding to specific receptors on the surface of cells, including A1, A2A, A2B, and A3 receptors. The activation of A1 receptors leads to a variety of physiological responses, such as vasodilation, negative chronotropy (slowing of heart rate), and negative inotropy (reduced contractility) of the heart, as well as inhibition of neurotransmitter release in the brain.

Adenosine A1 receptor antagonists work by binding to and blocking the action of adenosine at A1 receptors, thereby preventing or reducing its effects on these physiological processes. These drugs have been investigated for their potential therapeutic uses in various conditions, such as heart failure, cardiac arrest, and neurological disorders.

Examples of adenosine A1 receptor antagonists include:

* Dipyridamole: a vasodilator used to treat peripheral arterial disease and to prevent blood clots.
* Caffeine: a natural stimulant found in coffee, tea, and chocolate, which acts as a weak A1 receptor antagonist.
* Rolofylline: an experimental drug that has been investigated for its potential use in treating acute ischemic stroke and traumatic brain injury.
* KW-3902: another experimental drug that has been studied for its potential therapeutic effects in heart failure, cardiac arrest, and neurodegenerative disorders.

It's important to note that adenosine A1 receptor antagonists may have side effects and potential risks, and their use should be monitored and managed by healthcare professionals.

Purinergic P2 receptor antagonists are pharmaceutical agents that block the activity of P2 receptors, which are a type of cell surface receptor that binds extracellular nucleotides such as ATP and ADP. These receptors play important roles in various physiological processes, including neurotransmission, inflammation, and platelet aggregation.

P2 receptors are divided into two main subfamilies: P2X and P2Y. The P2X receptors are ligand-gated ion channels that allow the flow of ions across the cell membrane upon activation, while the P2Y receptors are G protein-coupled receptors that activate intracellular signaling pathways.

Purinergic P2 receptor antagonists are used in clinical medicine to treat various conditions, such as chronic pain, urinary incontinence, and cardiovascular diseases. For example, the P2X3 receptor antagonist gefapixant is being investigated for the treatment of refractory chronic cough, while the P2Y12 receptor antagonists clopidogrel and ticagrelor are used to prevent thrombosis in patients with acute coronary syndrome.

Overall, purinergic P2 receptor antagonists offer a promising therapeutic approach for various diseases by targeting specific receptors involved in pathological processes.

"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.

Narcotic antagonists are a class of medications that block the effects of opioids, a type of narcotic pain reliever, by binding to opioid receptors in the brain and blocking the activation of these receptors by opioids. This results in the prevention or reversal of opioid-induced effects such as respiratory depression, sedation, and euphoria. Narcotic antagonists are used for a variety of medical purposes, including the treatment of opioid overdose, the management of opioid dependence, and the prevention of opioid-induced side effects in certain clinical situations. Examples of narcotic antagonists include naloxone, naltrexone, and methylnaltrexone.

Histamine H1 antagonists, also known as H1 blockers or antihistamines, are a class of medications that work by blocking the action of histamine at the H1 receptor. Histamine is a chemical mediator released by mast cells and basophils in response to an allergic reaction or injury. It causes various symptoms such as itching, sneezing, runny nose, and wheal and flare reactions (hives).

H1 antagonists prevent the binding of histamine to its receptor, thereby alleviating these symptoms. They are commonly used to treat allergic conditions such as hay fever, hives, and eczema, as well as motion sickness and insomnia. Examples of H1 antagonists include diphenhydramine (Benadryl), loratadine (Claritin), cetirizine (Zyrtec), and doxylamine (Unisom).

Endothelin receptors are a type of G protein-coupled receptor that bind to endothelin, a potent vasoconstrictor peptide. There are two main types of endothelin receptors: ETA and ETB. ETA receptors are found in vascular smooth muscle cells and activate phospholipase C, leading to an increase in intracellular calcium and subsequent contraction of the smooth muscle. ETB receptors are found in both endothelial cells and vascular smooth muscle cells. In endothelial cells, ETB receptor activation leads to the release of nitric oxide and prostacyclin, which cause vasodilation. In vascular smooth muscle cells, ETB receptor activation causes vasoconstriction through a mechanism that is not fully understood.

Endothelin receptors play important roles in regulating blood flow, vascular remodeling, and the development of cardiovascular diseases such as hypertension and heart failure. They are also involved in the regulation of cell growth, differentiation, and apoptosis in various tissues.

Muscarinic antagonists, also known as muscarinic receptor antagonists or parasympatholytics, are a class of drugs that block the action of acetylcholine at muscarinic receptors. Acetylcholine is a neurotransmitter that plays an important role in the parasympathetic nervous system, which helps to regulate various bodily functions such as heart rate, digestion, and respiration.

Muscarinic antagonists work by binding to muscarinic receptors, which are found in various organs throughout the body, including the eyes, lungs, heart, and gastrointestinal tract. By blocking the action of acetylcholine at these receptors, muscarinic antagonists can produce a range of effects depending on the specific receptor subtype that is affected.

For example, muscarinic antagonists may be used to treat conditions such as chronic obstructive pulmonary disease (COPD) and asthma by relaxing the smooth muscle in the airways and reducing bronchoconstriction. They may also be used to treat conditions such as urinary incontinence or overactive bladder by reducing bladder contractions.

Some common muscarinic antagonists include atropine, scopolamine, ipratropium, and tiotropium. It's important to note that these drugs can have significant side effects, including dry mouth, blurred vision, constipation, and confusion, especially when used in high doses or for prolonged periods of time.

GABA-A receptor antagonists are pharmacological agents that block the action of gamma-aminobutyric acid (GABA) at GABA-A receptors. GABA is the primary inhibitory neurotransmitter in the central nervous system, and it exerts its effects by binding to GABA-A receptors, which are ligand-gated chloride channels. When GABA binds to these receptors, it opens the chloride channel, leading to an influx of chloride ions into the neuron and hyperpolarization of the membrane, making it less likely to fire.

GABA-A receptor antagonists work by binding to the GABA-A receptor and preventing GABA from binding, thereby blocking the inhibitory effects of GABA. This can lead to increased neuronal excitability and can result in a variety of effects depending on the specific antagonist and the location of the receptors involved.

GABA-A receptor antagonists have been used in research to study the role of GABA in various physiological processes, and some have been investigated as potential therapeutic agents for conditions such as anxiety, depression, and insomnia. However, their use is limited by their potential to cause seizures and other adverse effects due to excessive neuronal excitation. Examples of GABA-A receptor antagonists include picrotoxin, bicuculline, and flumazenil.

Adrenergic alpha-1 receptor antagonists, also known as alpha-blockers, are a class of medications that block the effects of the neurotransmitter norepinephrine at alpha-1 receptors. These receptors are found in various tissues throughout the body, including the smooth muscle of blood vessels, the bladder, and the eye.

When norepinephrine binds to alpha-1 receptors, it causes smooth muscle to contract, leading to vasoconstriction (constriction of blood vessels), increased blood pressure, and other effects. By blocking these receptors, alpha-blockers can cause relaxation of smooth muscle, leading to vasodilation (expansion of blood vessels), decreased blood pressure, and other effects.

Alpha-blockers are used in the treatment of various medical conditions, including hypertension (high blood pressure), benign prostatic hyperplasia (enlarged prostate), and pheochromocytoma (a rare tumor of the adrenal gland). Examples of alpha-blockers include doxazosin, prazosin, and terazosin.

It's important to note that while alpha-blockers can be effective in treating certain medical conditions, they can also have side effects, such as dizziness, lightheadedness, and orthostatic hypotension (a sudden drop in blood pressure when standing up). As with any medication, it's important to use alpha-blockers under the guidance of a healthcare provider.

Serotonin antagonists are a class of drugs that block the action of serotonin, a neurotransmitter, at specific receptor sites in the brain and elsewhere in the body. They work by binding to the serotonin receptors without activating them, thereby preventing the natural serotonin from binding and transmitting signals.

Serotonin antagonists are used in the treatment of various conditions such as psychiatric disorders, migraines, and nausea and vomiting associated with cancer chemotherapy. They can have varying degrees of affinity for different types of serotonin receptors (e.g., 5-HT2A, 5-HT3, etc.), which contributes to their specific therapeutic effects and side effect profiles.

Examples of serotonin antagonists include ondansetron (used to treat nausea and vomiting), risperidone and olanzapine (used to treat psychiatric disorders), and methysergide (used to prevent migraines). It's important to note that these medications should be used under the supervision of a healthcare provider, as they can have potential risks and interactions with other drugs.

GABA (gamma-aminobutyric acid) antagonists are substances that block the action of GABA, which is the primary inhibitory neurotransmitter in the central nervous system. GABA plays a crucial role in regulating neuronal excitability and reducing the transmission of nerve impulses.

GABA antagonists work by binding to the GABA receptors without activating them, thereby preventing the normal function of GABA and increasing neuronal activity. These agents can cause excitation of the nervous system, leading to various effects depending on the specific type of GABA receptor they target.

GABA antagonists are used in medical treatments for certain conditions, such as sleep disorders, depression, and cognitive enhancement. However, they can also have adverse effects, including anxiety, agitation, seizures, and even neurotoxicity at high doses. Examples of GABA antagonists include picrotoxin, bicuculline, and flumazenil.

Sialglycoproteins are a type of glycoprotein that have sialic acid as the terminal sugar in their oligosaccharide chains. These complex molecules are abundant on the surface of many cell types and play important roles in various biological processes, including cell recognition, cell-cell interactions, and protection against proteolytic degradation.

The presence of sialic acid on the outermost part of these glycoproteins makes them negatively charged, which can affect their interaction with other molecules such as lectins, antibodies, and enzymes. Sialglycoproteins are also involved in the regulation of various physiological functions, including blood coagulation, inflammation, and immune response.

Abnormalities in sialglycoprotein expression or structure have been implicated in several diseases, such as cancer, autoimmune disorders, and neurodegenerative conditions. Therefore, understanding the biology of sialoglycoproteins is important for developing new diagnostic and therapeutic strategies for these diseases.

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.

Adrenergic receptors are a type of G protein-coupled receptor that bind and respond to catecholamines, such as epinephrine (adrenaline) and norepinephrine (noradrenaline). Alpha adrenergic receptors (α-ARs) are a subtype of adrenergic receptors that are classified into two main categories: α1-ARs and α2-ARs.

The activation of α1-ARs leads to the activation of phospholipase C, which results in an increase in intracellular calcium levels and the activation of various signaling pathways that mediate diverse physiological responses such as vasoconstriction, smooth muscle contraction, and cell proliferation.

On the other hand, α2-ARs are primarily located on presynaptic nerve terminals where they function to inhibit the release of neurotransmitters, including norepinephrine. The activation of α2-ARs also leads to the inhibition of adenylyl cyclase and a decrease in intracellular cAMP levels, which can mediate various physiological responses such as sedation, analgesia, and hypotension.

Overall, α-ARs play important roles in regulating various physiological functions, including cardiovascular function, mood, and cognition, and are also involved in the pathophysiology of several diseases, such as hypertension, heart failure, and neurodegenerative disorders.

Alpha 1-antitrypsin (AAT, or α1-antiproteinase, A1AP) is a protein that is primarily produced by the liver and released into the bloodstream. It belongs to a group of proteins called serine protease inhibitors, which help regulate inflammation and protect tissues from damage caused by enzymes involved in the immune response.

Alpha 1-antitrypsin is particularly important for protecting the lungs from damage caused by neutrophil elastase, an enzyme released by white blood cells called neutrophils during inflammation. In the lungs, AAT binds to and inhibits neutrophil elastase, preventing it from degrading the extracellular matrix and damaging lung tissue.

Deficiency in alpha 1-antitrypsin can lead to chronic obstructive pulmonary disease (COPD) and liver disease. The most common cause of AAT deficiency is a genetic mutation that results in abnormal folding and accumulation of the protein within liver cells, leading to reduced levels of functional AAT in the bloodstream. This condition is called alpha 1-antitrypsin deficiency (AATD) and can be inherited in an autosomal codominant manner. Individuals with severe AATD may require augmentation therapy with intravenous infusions of purified human AAT to help prevent lung damage.

Leukotriene antagonists are a class of medications that work by blocking the action of leukotrienes, which are chemicals released by the immune system in response to an allergen or irritant. Leukotrienes cause airway muscles to tighten and inflammation in the airways, leading to symptoms such as wheezing, shortness of breath, and coughing. By blocking the action of leukotrienes, leukotriene antagonists can help relieve these symptoms and improve lung function. These medications are often used to treat asthma and allergic rhinitis (hay fever). Examples of leukotriene antagonists include montelukast, zafirlukast, and pranlukast.

Endothelin A (ETA) receptor is a type of G protein-coupled receptor that is activated by the peptide hormone endothelin-1, endothelin-2, and endothelin-3. It is widely expressed in various tissues and organs, including vascular smooth muscle cells, cardiac myocytes, fibroblasts, and kidney cells. Activation of ETA receptor leads to vasoconstriction, increased cell proliferation, and fibrosis, which contribute to the development of hypertension, heart failure, and chronic kidney disease. Therefore, ETA receptor antagonists have been developed as potential therapeutic agents for these conditions.

Serotonin receptors are a type of cell surface receptor that bind to the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). They are widely distributed throughout the body, including the central and peripheral nervous systems, where they play important roles in regulating various physiological processes such as mood, appetite, sleep, memory, learning, and cognition.

There are seven different classes of serotonin receptors (5-HT1 to 5-HT7), each with multiple subtypes, that exhibit distinct pharmacological properties and signaling mechanisms. These receptors are G protein-coupled receptors (GPCRs) or ligand-gated ion channels, which activate intracellular signaling pathways upon serotonin binding.

Serotonin receptors have been implicated in various neurological and psychiatric disorders, including depression, anxiety, schizophrenia, and migraine. Therefore, selective serotonin receptor agonists or antagonists are used as therapeutic agents for the treatment of these conditions.

N-Methyl-D-Aspartate (NMDA) receptors are a type of ionotropic glutamate receptor, which are found in the membranes of excitatory neurons in the central nervous system. They play a crucial role in synaptic plasticity, learning, and memory processes. NMDA receptors are ligand-gated channels that are permeable to calcium ions (Ca2+) and other cations.

NMDA receptors are composed of four subunits, which can be a combination of NR1, NR2A-D, and NR3A-B subunits. The binding of the neurotransmitter glutamate to the NR2 subunit and glycine to the NR1 subunit leads to the opening of the ion channel and the influx of Ca2+ ions.

NMDA receptors have a unique property in that they require both agonist binding and membrane depolarization for full activation, making them sensitive to changes in the electrical activity of the neuron. This property allows NMDA receptors to act as coincidence detectors, playing a critical role in synaptic plasticity and learning.

Abnormal functioning of NMDA receptors has been implicated in various neurological disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, and chronic pain. Therefore, NMDA receptors are a common target for drug development in the treatment of these conditions.

Serotonin 5-HT1 receptor antagonists are a class of pharmaceutical drugs that block the activation of serotonin 5-HT1 receptors. Serotonin, also known as 5-hydroxytryptamine (5-HT), is a neurotransmitter that plays a role in various physiological functions, including mood regulation, appetite control, and sensory perception. The 5-HT1 receptor family includes several subtypes (5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, and 5-HT1F) that are widely distributed throughout the central and peripheral nervous systems.

When serotonin binds to these receptors, it triggers a series of intracellular signaling events that can have excitatory or inhibitory effects on neuronal activity. By blocking the interaction between serotonin and 5-HT1 receptors, antagonists modulate the downstream consequences of receptor activation.

Serotonin 5-HT1 receptor antagonists are used in various clinical contexts to treat or manage a range of conditions:

1. Migraine prevention: Some 5-HT1B/1D receptor antagonists, such as sumatriptan and rizatriptan, are highly effective in aborting migraine attacks by constricting dilated cranial blood vessels and reducing the release of pro-inflammatory neuropeptides.
2. Nausea and vomiting: Certain 5-HT3 receptor antagonists, like ondansetron and granisetron, are used to prevent chemotherapy-induced nausea and vomiting by blocking the activation of emetic circuits in the brainstem.
3. Psychiatric disorders: Although not widely used, some 5-HT1A receptor antagonists have shown promise in treating depression and anxiety disorders due to their ability to modulate serotonergic neurotransmission.
4. Neuroprotection: Preclinical studies suggest that 5-HT1A receptor agonists may have neuroprotective effects in various neurological conditions, such as Parkinson's disease and stroke. However, further research is needed to establish their clinical utility.

In summary, serotonin 5-HT1 receptor antagonists are a diverse group of medications with applications in migraine prevention, nausea and vomiting management, psychiatric disorders, and potential neuroprotection. Their unique pharmacological profiles enable them to target specific pathophysiological mechanisms underlying various conditions, making them valuable tools in modern therapeutics.

Nicotinic antagonists are a class of drugs that block the action of nicotine at nicotinic acetylcholine receptors (nAChRs). These receptors are found in the nervous system and are activated by the neurotransmitter acetylcholine, as well as by nicotine. When nicotine binds to these receptors, it can cause the release of various neurotransmitters, including dopamine, which can lead to rewarding effects and addiction.

Nicotinic antagonists work by binding to nAChRs and preventing nicotine from activating them. This can help to reduce the rewarding effects of nicotine and may be useful in treating nicotine addiction. Examples of nicotinic antagonists include mecamylamine, varenicline, and cytisine.

It's important to note that while nicotinic antagonists can help with nicotine addiction, they can also have side effects, such as nausea, vomiting, and abnormal dreams. Additionally, some people may experience more serious side effects, such as seizures or cardiovascular problems, so it's important to use these medications under the close supervision of a healthcare provider.

Dizocilpine maleate is a chemical compound that is commonly known as an N-methyl-D-aspartate (NMDA) receptor antagonist. It is primarily used in research settings to study the role of NMDA receptors in various physiological processes, including learning and memory.

The chemical formula for dizocilpine maleate is C16H24Cl2N2O4·C4H4O4. The compound is a white crystalline powder that is soluble in water and alcohol. It has potent psychoactive effects and has been investigated as a potential treatment for various neurological and psychiatric disorders, although it has not been approved for clinical use.

Dizocilpine maleate works by blocking the action of glutamate, a neurotransmitter that plays a key role in learning and memory, at NMDA receptors in the brain. By doing so, it can alter various cognitive processes and has been shown to have anticonvulsant, analgesic, and neuroprotective effects in animal studies. However, its use is associated with significant side effects, including hallucinations, delusions, and memory impairment, which have limited its development as a therapeutic agent.

Interleukin-1 (IL-1) receptors are a type of cell surface receptor that bind to and mediate the effects of interleukin-1 cytokines, which are involved in the regulation of inflammatory and immune responses. There are two main types of IL-1 receptors:

1. Type I IL-1 receptor (IL-1R1): This is a transmembrane protein that consists of three domains - an extracellular domain, a transmembrane domain, and an intracellular domain. The extracellular domain contains the binding site for IL-1 cytokines, while the intracellular domain is involved in signal transduction and activation of downstream signaling pathways.
2. Type II IL-1 receptor (IL-1R2): This is a decoy receptor that lacks an intracellular signaling domain and functions to regulate IL-1 activity by preventing its interaction with IL-1R1.

IL-1 receptors are widely expressed in various tissues and cell types, including immune cells, endothelial cells, and nervous system cells. Activation of IL-1 receptors leads to the induction of a variety of biological responses, such as fever, production of acute phase proteins, activation of immune cells, and modulation of pain sensitivity. Dysregulation of IL-1 signaling has been implicated in various pathological conditions, including autoimmune diseases, chronic inflammation, and neurodegenerative disorders.

Adrenergic alpha-2 receptor antagonists are a class of medications that block the action of norepinephrine, a neurotransmitter and hormone, at adrenergic alpha-2 receptors. These receptors are found in the central and peripheral nervous system and play a role in regulating various physiological functions such as blood pressure, heart rate, and insulin secretion.

By blocking the action of norepinephrine at these receptors, adrenergic alpha-2 receptor antagonists can increase sympathetic nervous system activity, leading to vasodilation, increased heart rate, and increased insulin secretion. These effects make them useful in the treatment of conditions such as hypotension (low blood pressure), opioid-induced sedation and respiratory depression, and diagnostic procedures that require vasodilation.

Examples of adrenergic alpha-2 receptor antagonists include yohimbine, idazoxan, and atipamezole. It's important to note that these medications can have significant side effects, including hypertension, tachycardia, and agitation, and should be used under the close supervision of a healthcare provider.

Adrenergic alpha-antagonists, also known as alpha-blockers, are a class of medications that block the effects of adrenaline and noradrenaline at alpha-adrenergic receptors. These receptors are found in various tissues throughout the body, including the smooth muscle of blood vessels, the heart, the genitourinary system, and the eyes.

When alpha-blockers bind to these receptors, they prevent the activation of the sympathetic nervous system, which is responsible for the "fight or flight" response. This results in a relaxation of the smooth muscle, leading to vasodilation (widening of blood vessels), decreased blood pressure, and increased blood flow.

Alpha-blockers are used to treat various medical conditions, such as hypertension (high blood pressure), benign prostatic hyperplasia (enlarged prostate), pheochromocytoma (a rare tumor of the adrenal gland), and certain types of glaucoma.

Examples of alpha-blockers include doxazosin, prazosin, terazosin, and tamsulosin. Side effects of alpha-blockers may include dizziness, lightheadedness, headache, weakness, and orthostatic hypotension (a sudden drop in blood pressure upon standing).

Biphenyl compounds, also known as diphenyls, are a class of organic compounds consisting of two benzene rings linked by a single carbon-carbon bond. The chemical structure of biphenyl compounds can be represented as C6H5-C6H5. These compounds are widely used in the industrial sector, including as intermediates in the synthesis of other chemicals, as solvents, and in the production of plastics and dyes. Some biphenyl compounds also have biological activity and can be found in natural products. For example, some plant-derived compounds that belong to this class have been shown to have anti-inflammatory, antioxidant, and anticancer properties.

Benzazepines are a class of heterocyclic compounds that contain a benzene fused to a diazepine ring. In the context of pharmaceuticals, benzazepines refer to a group of drugs with various therapeutic uses, such as antipsychotics and antidepressants. Some examples of benzazepine-derived drugs include clozapine, olanzapine, and loxoprofen. These drugs have complex mechanisms of action, often involving multiple receptor systems in the brain.

Tetrazoles are a class of heterocyclic aromatic organic compounds that contain a five-membered ring with four nitrogen atoms and one carbon atom. They have the chemical formula of C2H2N4. Tetrazoles are stable under normal conditions, but can decompose explosively when heated or subjected to strong shock.

In the context of medicinal chemistry, tetrazoles are sometimes used as bioisosteres for carboxylic acids, as they can mimic some of their chemical and biological properties. This has led to the development of several drugs that contain tetrazole rings, such as the antiviral drug tenofovir and the anti-inflammatory drug celecoxib.

However, it's important to note that 'tetrazoles' is not a medical term per se, but rather a chemical term that can be used in the context of medicinal chemistry or pharmacology.

A radioligand assay is a type of in vitro binding assay used in molecular biology and pharmacology to measure the affinity and quantity of a ligand (such as a drug or hormone) to its specific receptor. In this technique, a small amount of a radioactively labeled ligand, also known as a radioligand, is introduced to a sample containing the receptor of interest. The radioligand binds competitively with other unlabeled ligands present in the sample for the same binding site on the receptor. After allowing sufficient time for binding, the reaction is stopped, and the amount of bound radioligand is measured using a technique such as scintillation counting. The data obtained from this assay can be used to determine the dissociation constant (Kd) and maximum binding capacity (Bmax) of the receptor-ligand interaction, which are important parameters in understanding the pharmacological properties of drugs and other ligands.

I'm sorry for any confusion, but "Pyridines" is not a medical term. It is a chemical term that refers to a class of organic compounds with the chemical structure of a six-membered ring containing one nitrogen atom and five carbon atoms (heterocyclic aromatic compound).

In a biological or medical context, pyridine derivatives can be found in various natural and synthetic substances. For example, some medications contain pyridine rings as part of their chemical structure. However, "Pyridines" itself is not a medical term or condition.

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.

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.

Serotonin receptor agonists are a class of medications that bind to and activate serotonin receptors in the body, mimicking the effects of the neurotransmitter serotonin. These drugs can have various effects depending on which specific serotonin receptors they act upon. Some serotonin receptor agonists are used to treat conditions such as migraines, cluster headaches, and Parkinson's disease, while others may be used to stimulate appetite or reduce anxiety. It is important to note that some serotonin receptor agonists can have serious side effects, particularly when taken in combination with other medications that affect serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors (MAOIs). This can lead to a condition called serotonin syndrome, which is characterized by symptoms such as agitation, confusion, rapid heart rate, high blood pressure, and muscle stiffness.

Cyclic peptides are a type of peptides in which the N-terminus and C-terminus of the peptide chain are linked to form a circular structure. This is in contrast to linear peptides, which have a straight peptide backbone with a free N-terminus and C-terminus. The cyclization of peptides can occur through various mechanisms, including the formation of an amide bond between the N-terminal amino group and the C-terminal carboxylic acid group (head-to-tail cyclization), or through the formation of a bond between side chain functional groups.

Cyclic peptides have unique structural and chemical properties that make them valuable in medical and therapeutic applications. For example, they are more resistant to degradation by enzymes compared to linear peptides, which can increase their stability and half-life in the body. Additionally, the cyclic structure allows for greater conformational rigidity, which can enhance their binding affinity and specificity to target molecules.

Cyclic peptides have been explored as potential therapeutics for a variety of diseases, including cancer, infectious diseases, and neurological disorders. They have also been used as tools in basic research to study protein-protein interactions and cell signaling pathways.

Sulfonamides are a group of synthetic antibacterial drugs that contain the sulfonamide group (SO2NH2) in their chemical structure. They are bacteriostatic agents, meaning they inhibit bacterial growth rather than killing them outright. Sulfonamides work by preventing the bacteria from synthesizing folic acid, which is essential for their survival.

The first sulfonamide drug was introduced in the 1930s and since then, many different sulfonamides have been developed with varying chemical structures and pharmacological properties. They are used to treat a wide range of bacterial infections, including urinary tract infections, respiratory tract infections, skin and soft tissue infections, and ear infections.

Some common sulfonamide drugs include sulfisoxazole, sulfamethoxazole, and trimethoprim-sulfamethoxazole (a combination of a sulfonamide and another antibiotic called trimethoprim). While sulfonamides are generally safe and effective when used as directed, they can cause side effects such as rash, nausea, and allergic reactions. It is important to follow the prescribing physician's instructions carefully and to report any unusual symptoms or side effects promptly.

A drug interaction is the effect of combining two or more drugs, or a drug and another substance (such as food or alcohol), which can alter the effectiveness or side effects of one or both of the substances. These interactions can be categorized as follows:

1. Pharmacodynamic interactions: These occur when two or more drugs act on the same target organ or receptor, leading to an additive, synergistic, or antagonistic effect. For example, taking a sedative and an antihistamine together can result in increased drowsiness due to their combined depressant effects on the central nervous system.
2. Pharmacokinetic interactions: These occur when one drug affects the absorption, distribution, metabolism, or excretion of another drug. For example, taking certain antibiotics with grapefruit juice can increase the concentration of the antibiotic in the bloodstream, leading to potential toxicity.
3. Food-drug interactions: Some drugs may interact with specific foods, affecting their absorption, metabolism, or excretion. An example is the interaction between warfarin (a blood thinner) and green leafy vegetables, which can increase the risk of bleeding due to enhanced vitamin K absorption from the vegetables.
4. Drug-herb interactions: Some herbal supplements may interact with medications, leading to altered drug levels or increased side effects. For instance, St. John's Wort can decrease the effectiveness of certain antidepressants and oral contraceptives by inducing their metabolism.
5. Drug-alcohol interactions: Alcohol can interact with various medications, causing additive sedative effects, impaired judgment, or increased risk of liver damage. For example, combining alcohol with benzodiazepines or opioids can lead to dangerous levels of sedation and respiratory depression.

It is essential for healthcare providers and patients to be aware of potential drug interactions to minimize adverse effects and optimize treatment outcomes.

Indole is not strictly a medical term, but it is a chemical compound that can be found in the human body and has relevance to medical and biological research. Indoles are organic compounds that contain a bicyclic structure consisting of a six-membered benzene ring fused to a five-membered pyrrole ring.

In the context of medicine, indoles are particularly relevant due to their presence in certain hormones and other biologically active molecules. For example, the neurotransmitter serotonin contains an indole ring, as does the hormone melatonin. Indoles can also be found in various plant-based foods, such as cruciferous vegetables (e.g., broccoli, kale), and have been studied for their potential health benefits.

Some indoles, like indole-3-carbinol and diindolylmethane, are found in these vegetables and can have anti-cancer properties by modulating estrogen metabolism, reducing inflammation, and promoting cell death (apoptosis) in cancer cells. However, it is essential to note that further research is needed to fully understand the potential health benefits and risks associated with indoles.

Histamine H3 antagonists, also known as inverse agonists, are a class of drugs that block the activity of histamine at the H3 receptor. Histamine is a naturally occurring neurotransmitter and autacoid involved in various physiological functions, including the modulation of wakefulness and arousal, regulation of food intake, and control of blood pressure and fluid balance.

The H3 receptor is primarily located in the central nervous system (CNS) and acts as an auto-receptor on histamine-containing neurons to regulate the release of histamine. By blocking the activity of these receptors, histamine H3 antagonists increase the release of histamine in the CNS, which can lead to increased wakefulness and arousal.

Histamine H3 antagonists have been studied for their potential therapeutic use in various neurological and psychiatric disorders, including narcolepsy, attention deficit hyperactivity disorder (ADHD), and Alzheimer's disease. However, further research is needed to fully understand the clinical benefits and safety of these drugs.

"Competitive binding" is a term used in pharmacology and biochemistry to describe the behavior of two or more molecules (ligands) competing for the same binding site on a target protein or receptor. In this context, "binding" refers to the physical interaction between a ligand and its target.

When a ligand binds to a receptor, it can alter the receptor's function, either activating or inhibiting it. If multiple ligands compete for the same binding site, they will compete to bind to the receptor. The ability of each ligand to bind to the receptor is influenced by its affinity for the receptor, which is a measure of how strongly and specifically the ligand binds to the receptor.

In competitive binding, if one ligand is present in high concentrations, it can prevent other ligands with lower affinity from binding to the receptor. This is because the higher-affinity ligand will have a greater probability of occupying the binding site and blocking access to the other ligands. The competition between ligands can be described mathematically using equations such as the Langmuir isotherm, which describes the relationship between the concentration of ligand and the fraction of receptors that are occupied by the ligand.

Competitive binding is an important concept in drug development, as it can be used to predict how different drugs will interact with their targets and how they may affect each other's activity. By understanding the competitive binding properties of a drug, researchers can optimize its dosage and delivery to maximize its therapeutic effect while minimizing unwanted side effects.

Pyrazoles are heterocyclic aromatic organic compounds that contain a six-membered ring with two nitrogen atoms at positions 1 and 2. The chemical structure of pyrazoles consists of a pair of nitrogen atoms adjacent to each other in the ring, which makes them unique from other azole heterocycles such as imidazoles or triazoles.

Pyrazoles have significant biological activities and are found in various pharmaceuticals, agrochemicals, and natural products. Some pyrazole derivatives exhibit anti-inflammatory, analgesic, antipyretic, antimicrobial, antiviral, antifungal, and anticancer properties.

In the medical field, pyrazoles are used in various drugs to treat different conditions. For example, celecoxib (Celebrex) is a selective COX-2 inhibitor used for pain relief and inflammation reduction in arthritis patients. It contains a pyrazole ring as its core structure. Similarly, febuxostat (Uloric) is a medication used to treat gout, which also has a pyrazole moiety.

Overall, pyrazoles are essential compounds with significant medical applications and potential for further development in drug discovery and design.

Hypoxia-Inducible Factor 1 (HIF-1) is a transcription factor that plays a crucial role in the body's response to low oxygen levels, also known as hypoxia. HIF-1 is a heterodimeric protein composed of two subunits: an alpha subunit (HIF-1α) and a beta subunit (HIF-1β).

The alpha subunit, HIF-1α, is the regulatory subunit that is subject to oxygen-dependent degradation. Under normal oxygen conditions (normoxia), HIF-1α is constantly produced in the cell but is rapidly degraded by proteasomes due to hydroxylation of specific proline residues by prolyl hydroxylase domain-containing proteins (PHDs). This hydroxylation reaction requires oxygen as a substrate, and under hypoxic conditions, the activity of PHDs is inhibited, leading to the stabilization and accumulation of HIF-1α.

Once stabilized, HIF-1α translocates to the nucleus, where it heterodimerizes with HIF-1β and binds to hypoxia-responsive elements (HREs) in the promoter regions of target genes. This binding results in the activation of gene transcription programs that promote cellular adaptation to low oxygen levels. These adaptive responses include increased erythropoiesis, angiogenesis, glucose metabolism, and pH regulation, among others.

Therefore, HIF-1α is a critical regulator of the body's response to hypoxia, and its dysregulation has been implicated in various pathological conditions, including cancer, cardiovascular disease, and neurodegenerative disorders.

Quinoxalines are not a medical term, but rather an organic chemical compound. They are a class of heterocyclic aromatic compounds made up of a benzene ring fused to a pyrazine ring. Quinoxalines have no specific medical relevance, but some of their derivatives have been synthesized and used in medicinal chemistry as antibacterial, antifungal, and antiviral agents. They are also used in the production of dyes and pigments.

"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.

Azepines are heterocyclic chemical compounds that contain a seven-membered ring with one nitrogen atom and six carbon atoms. The term "azepine" refers to the basic structure, and various substituted azepines exist with different functional groups attached to the carbon and nitrogen atoms.

Azepines are not typically used in medical contexts as a therapeutic agent or a target for drug design. However, some azepine derivatives have been investigated for their potential biological activities, such as anti-inflammatory, antiviral, and anticancer properties. These compounds may be the subject of ongoing research, but they are not yet established as medical treatments.

It's worth noting that while azepines themselves are not a medical term, some of their derivatives or analogs may have medical relevance. Therefore, it is essential to consult medical literature and databases for accurate and up-to-date information on the medical use of specific azepine compounds.

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.

Losartan is an angiotensin II receptor blocker (ARB) medication that is primarily used to treat hypertension (high blood pressure), but can also be used to manage chronic heart failure and protect against kidney damage in patients with type 2 diabetes. It works by blocking the action of angiotensin II, a hormone that causes blood vessels to narrow and blood pressure to rise. By blocking this hormone's effects, losartan helps relax and widen blood vessels, making it easier for the heart to pump blood and reducing the workload on the cardiovascular system.

The medical definition of losartan is: "A synthetic angiotensin II receptor antagonist used in the treatment of hypertension, chronic heart failure, and diabetic nephropathy. It selectively blocks the binding of angiotensin II to the AT1 receptor, leading to vasodilation, decreased aldosterone secretion, and increased renin activity."

Endothelin-1 is a small peptide (21 amino acids) and a potent vasoconstrictor, which means it narrows blood vessels. It is primarily produced by the endothelial cells that line the interior surface of blood vessels. Endothelin-1 plays a crucial role in regulating vascular tone, cell growth, and inflammation. Its dysregulation has been implicated in various cardiovascular diseases, such as hypertension and heart failure. It exerts its effects by binding to specific G protein-coupled receptors (ETA and ETB) on the surface of target cells.

GABA-B receptor antagonists are pharmacological agents that block the activation of GABA-B receptors, which are G protein-coupled receptors found in the central and peripheral nervous systems. Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the brain, and it exerts its effects by binding to GABA-A and GABA-B receptors.

GABA-B receptor antagonists work by preventing GABA from binding to these receptors, thereby blocking the inhibitory effects of GABA. This can lead to increased neuronal excitability and can have various pharmacological effects depending on the specific receptor subtype and location in the body.

GABA-B receptor antagonists have been investigated for their potential therapeutic use in a variety of neurological and psychiatric disorders, such as epilepsy, depression, anxiety, and substance abuse disorders. However, their clinical use is still not well established due to limited efficacy and potential side effects, including increased anxiety, agitation, and seizures.

Substance P is an undecapeptide neurotransmitter and neuromodulator, belonging to the tachykinin family of peptides. It is widely distributed in the central and peripheral nervous systems and is primarily found in sensory neurons. Substance P plays a crucial role in pain transmission, inflammation, and various autonomic functions. It exerts its effects by binding to neurokinin 1 (NK-1) receptors, which are expressed on the surface of target cells. Apart from nociception and inflammation, Substance P is also involved in regulating emotional behaviors, smooth muscle contraction, and fluid balance.

The alpha7 nicotinic acetylcholine receptor (α7nAChR) is a type of cholinergic receptor found in the nervous system that is activated by the neurotransmitter acetylcholine. It is a ligand-gated ion channel that is widely distributed throughout the central and peripheral nervous systems, including in the hippocampus, cortex, thalamus, and autonomic ganglia.

The α7nAChR is composed of five subunits arranged around a central pore, and it has a high permeability to calcium ions (Ca2+). When acetylcholine binds to the receptor, it triggers a conformational change that opens the ion channel, allowing Ca2+ to flow into the cell. This influx of Ca2+ can activate various intracellular signaling pathways and have excitatory or inhibitory effects on neuronal activity, depending on the location and function of the receptor.

The α7nAChR has been implicated in a variety of physiological processes, including learning and memory, attention, sensory perception, and motor control. It has also been studied as a potential therapeutic target for various neurological and psychiatric disorders, such as Alzheimer's disease, schizophrenia, and pain.

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.

Bradykinin receptors are a type of G protein-coupled receptor (GPCR) that binds to and is activated by the peptide hormone bradykinin. There are two main types of bradykinin receptors, B1 and B2, which are distinguished by their pharmacological properties, distribution, and function.

Bradykinin Receptor B1 (B1R) is upregulated during tissue injury and inflammation, and it mediates pain, hyperalgesia, and vasodilation. The activation of B1R also promotes the production of pro-inflammatory cytokines and chemokines, contributing to the development of chronic inflammation.

Bradykinin Receptor B2 (B2R) is constitutively expressed in various tissues, including the vascular endothelium, smooth muscle, and nervous system. It mediates many of the physiological effects of bradykinin, such as vasodilation, increased vascular permeability, and pain sensation. B2R also plays a role in the regulation of blood pressure, fluid balance, and tissue repair.

Both B1R and B2R are involved in the pathogenesis of several diseases, including inflammatory disorders, cardiovascular diseases, and chronic pain conditions. Therefore, targeting these receptors with specific drugs has emerged as a promising therapeutic strategy for treating various medical conditions.

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.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

Cimetidine is a histamine-2 (H2) receptor antagonist, which is a type of medication that reduces the production of stomach acid. It works by blocking the action of histamine on the H2 receptors in the stomach, which are responsible for stimulating the release of stomach acid. By blocking these receptors, cimetidine reduces the amount of stomach acid produced and can help to relieve symptoms such as heartburn, indigestion, and stomach ulcers.

Cimetidine is available by prescription in various forms, including tablets, capsules, and liquid. It is typically taken two or three times a day, depending on the specific condition being treated. Common side effects of cimetidine may include headache, dizziness, diarrhea, and constipation.

In addition to its use in treating stomach acid-related conditions, cimetidine has also been studied for its potential anti-cancer properties. Some research suggests that it may help to enhance the immune system's response to cancer cells and reduce the growth of certain types of tumors. However, more research is needed to confirm these effects and determine the optimal dosage and duration of treatment.

Neurokinin-1 (NK-1) receptors are a type of G protein-coupled receptor that bind to the neuropeptide substance P, which is a member of the tachykinin family. These receptors are widely distributed in the central and peripheral nervous systems and play important roles in various physiological functions, including pain transmission, neuroinflammation, and emesis (vomiting).

NK-1 receptors are activated by substance P, which binds to the receptor's extracellular domain and triggers a signaling cascade that leads to the activation of various intracellular signaling pathways. This activation can ultimately result in the modulation of neuronal excitability, neurotransmitter release, and gene expression.

In addition to their role in normal physiological processes, NK-1 receptors have also been implicated in a number of pathological conditions, including pain, inflammation, and neurodegenerative disorders. As such, NK-1 receptor antagonists have been developed as potential therapeutic agents for the treatment of these conditions.

Adenosine A3 receptor antagonists are a class of pharmaceutical compounds that block the action of adenosine at the A3 receptor. Adenosine is a naturally occurring purine nucleoside that acts as a neurotransmitter and modulator of various physiological processes, including cardiovascular function, immune response, and neuromodulation.

The A3 receptor is one of four subtypes of adenosine receptors (A1, A2A, A2B, and A3) that are widely distributed throughout the body. The activation of A3 receptors has been implicated in a variety of pathological conditions, including inflammation, pain, ischemia-reperfusion injury, and cancer.

Adenosine A3 receptor antagonists have been investigated as potential therapeutic agents for various diseases, such as rheumatoid arthritis, chronic pain, ischemic heart disease, and cancer. These compounds work by preventing the binding of adenosine to its receptor, thereby blocking its downstream signaling pathways.

Some examples of Adenosine A3 receptor antagonists include:

* MRS1523
* MRE-2029F20
* LUF5834
* VUF5574
* OT-7962

It is important to note that while Adenosine A3 receptor antagonists have shown promise in preclinical studies, their clinical efficacy and safety profile are still being evaluated in ongoing research.

The Endothelin B (ETB) receptor is a type of G protein-coupled receptor that binds to endothelin, a potent vasoconstrictor peptide. ETB receptors are expressed in various tissues, including vascular endothelial cells and smooth muscle cells. When endothelin binds to the ETB receptor, it can cause both vasodilation and vasoconstriction, depending on the location of the receptor. In endothelial cells, activation of ETB receptors leads to the production of nitric oxide, a potent vasodilator. However, in vascular smooth muscle cells, activation of ETB receptors can cause vasoconstriction by increasing intracellular calcium levels.

ETB receptors have also been implicated in various physiological and pathophysiological processes, including cardiovascular function, kidney function, and neurotransmission. In the cardiovascular system, ETB receptors play a role in regulating blood pressure and vascular remodeling. In the kidneys, they are involved in the regulation of sodium and water balance. Additionally, ETB receptors have been implicated in the development of pulmonary hypertension, heart failure, and chronic kidney disease.

Overall, Endothelin B receptors play a critical role in regulating various physiological processes, and their dysregulation has been associated with several pathological conditions.

Purinergic P2X receptor antagonists are pharmaceutical agents that block the activation of P2X receptors, which are ligand-gated ion channels found in the cell membranes of various cell types, including excitable cells such as neurons and muscle cells. These receptors are activated by extracellular adenosine triphosphate (ATP) and play important roles in a variety of physiological processes, including neurotransmission, pain perception, and inflammation.

P2X receptor antagonists work by binding to the receptor and preventing ATP from activating it, thereby blocking its downstream effects. These drugs have potential therapeutic uses in various medical conditions, such as chronic pain, urinary incontinence, and ischemia-reperfusion injury. However, their development and use are still in the early stages of research, and more studies are needed to fully understand their mechanisms of action and safety profiles.

Piperazines are a class of heterocyclic organic compounds that contain a seven-membered ring with two nitrogen atoms at positions 1 and 4. They have the molecular formula N-NRR' where R and R' can be alkyl or aryl groups. Piperazines have a wide range of uses in pharmaceuticals, agrochemicals, and as building blocks in organic synthesis.

In a medical context, piperazines are used in the manufacture of various drugs, including some antipsychotics, antidepressants, antihistamines, and anti-worm medications. For example, the antipsychotic drug trifluoperazine and the antidepressant drug nefazodone both contain a piperazine ring in their chemical structure.

However, it's important to note that some piperazines are also used as recreational drugs due to their stimulant and euphoric effects. These include compounds such as BZP (benzylpiperazine) and TFMPP (trifluoromethylphenylpiperazine), which have been linked to serious health risks, including addiction, seizures, and death. Therefore, the use of these substances should be avoided.

'Animal behavior' refers to the actions or responses of animals to various stimuli, including their interactions with the environment and other individuals. It is the study of the actions of animals, whether they are instinctual, learned, or a combination of both. Animal behavior includes communication, mating, foraging, predator avoidance, and social organization, among other things. The scientific study of animal behavior is called ethology. This field seeks to understand the evolutionary basis for behaviors as well as their physiological and psychological mechanisms.

Pyrrolidines are not a medical term per se, but they are a chemical compound that can be encountered in the field of medicine and pharmacology. Pyrrolidine is an organic compound with the molecular formula (CH2)4NH. It is a cyclic secondary amine, which means it contains a nitrogen atom surrounded by four carbon atoms in a ring structure.

Pyrrolidines can be found in certain natural substances and are also synthesized for use in pharmaceuticals and research. They have been used as building blocks in the synthesis of various drugs, including some muscle relaxants, antipsychotics, and antihistamines. Additionally, pyrrolidine derivatives can be found in certain plants and fungi, where they may contribute to biological activity or toxicity.

It is important to note that while pyrrolidines themselves are not a medical condition or diagnosis, understanding their chemical properties and uses can be relevant to the study and development of medications.

Alpha-1 adrenergic receptors (also known as α1-adrenoreceptors) are a type of G protein-coupled receptor that binds catecholamines, such as norepinephrine and epinephrine. These receptors are primarily found in the smooth muscle of various organs, including the vasculature, heart, liver, kidneys, gastrointestinal tract, and genitourinary system.

When an alpha-1 adrenergic receptor is activated by a catecholamine, it triggers a signaling cascade that leads to the activation of phospholipase C, which in turn activates protein kinase C and increases intracellular calcium levels. This ultimately results in smooth muscle contraction, increased heart rate and force of contraction, and vasoconstriction.

Alpha-1 adrenergic receptors are also found in the central nervous system, where they play a role in regulating wakefulness, attention, and anxiety. There are three subtypes of alpha-1 adrenergic receptors (α1A, α1B, and α1D), each with distinct physiological roles and pharmacological properties.

In summary, alpha-1 adrenergic receptors are a type of G protein-coupled receptor that binds catecholamines and mediates various physiological responses, including smooth muscle contraction, increased heart rate and force of contraction, vasoconstriction, and regulation of wakefulness and anxiety.

Interleukin-1 (IL-1) is a type of cytokine, which are proteins that play a crucial role in cell signaling. Specifically, IL-1 is a pro-inflammatory cytokine that is involved in the regulation of immune and inflammatory responses in the body. It is produced by various cells, including monocytes, macrophages, and dendritic cells, in response to infection or injury.

IL-1 exists in two forms, IL-1α and IL-1β, which have similar biological activities but are encoded by different genes. Both forms of IL-1 bind to the same receptor, IL-1R, and activate intracellular signaling pathways that lead to the production of other cytokines, chemokines, and inflammatory mediators.

IL-1 has a wide range of biological effects, including fever induction, activation of immune cells, regulation of hematopoiesis (the formation of blood cells), and modulation of bone metabolism. Dysregulation of IL-1 production or activity has been implicated in various inflammatory diseases, such as rheumatoid arthritis, gout, and inflammatory bowel disease. Therefore, IL-1 is an important target for the development of therapies aimed at modulating the immune response and reducing inflammation.

Cholecystokinin (CCK) receptors are a type of G protein-coupled receptor that bind to and are activated by the hormone cholecystokinin. CCK is a peptide hormone that is released by cells in the duodenum in response to the presence of nutrients, particularly fat and protein. It has several physiological roles, including stimulating the release of digestive enzymes from the pancreas, promoting the contraction of the gallbladder and relaxation of the sphincter of Oddi (which controls the flow of bile and pancreatic juice into the duodenum), and inhibiting gastric emptying.

There are two main types of CCK receptors, known as CCK-A and CCK-B receptors. CCK-A receptors are found in the pancreas, gallbladder, and gastrointestinal tract, where they mediate the effects of CCK on digestive enzyme secretion, gallbladder contraction, and gastric emptying. CCK-B receptors are found primarily in the brain, where they play a role in regulating appetite and satiety.

CCK receptors have been studied as potential targets for the development of drugs to treat various gastrointestinal disorders, such as pancreatitis, gallstones, and obesity. However, more research is needed to fully understand their roles and therapeutic potential.

Devazepide is not a medical term, but it is a pharmaceutical compound. It is a selective and competitive antagonist of the benzodiazepine site on GABA(A) receptors. This means that devazepide blocks the effects of benzodiazepines by binding to the same site on the GABA(A) receptor without activating it.

Devazepide has been studied in research settings as a potential treatment for alcohol use disorder and anxiety disorders, but it is not currently approved for medical use in any country.

Therefore, there is no official medical definition for 'Devazepide'.

Adrenergic antagonists, also known as beta blockers or sympatholytic drugs, are a class of medications that block the effects of adrenaline and noradrenaline (also known as epinephrine and norepinephrine) on the body. These neurotransmitters are part of the sympathetic nervous system and play a role in the "fight or flight" response, increasing heart rate, blood pressure, and respiratory rate.

Adrenergic antagonists work by binding to beta-adrenergic receptors in the body, preventing the neurotransmitters from activating them. This results in a decrease in heart rate, blood pressure, and respiratory rate. These medications are used to treat various conditions such as hypertension, angina, heart failure, arrhythmias, glaucoma, and anxiety disorders.

There are two types of adrenergic antagonists: beta blockers and alpha blockers. Beta blockers selectively bind to beta-adrenergic receptors, while alpha blockers bind to alpha-adrenergic receptors. Some medications, such as labetalol, have both beta and alpha blocking properties.

It is important to note that adrenergic antagonists can interact with other medications and may cause side effects, so it is essential to use them under the guidance of a healthcare professional.

**Prazosin** is an antihypertensive drug, which belongs to the class of medications called alpha-blockers. It works by relaxing the muscles in the blood vessels, which helps to lower blood pressure and improve blood flow. Prazosin is primarily used to treat high blood pressure (hypertension), but it may also be used for the management of symptoms related to enlarged prostate (benign prostatic hyperplasia).

In a medical definition context:

Prazosin: A selective α1-adrenergic receptor antagonist, used in the treatment of hypertension and benign prostatic hyperplasia. It acts by blocking the action of norepinephrine on the smooth muscle of blood vessels, resulting in vasodilation and decreased peripheral vascular resistance. This leads to a reduction in blood pressure and an improvement in urinary symptoms associated with an enlarged prostate.

Thromboxane receptors are a type of G protein-coupled receptor that binds thromboxane A2 (TXA2), a powerful inflammatory mediator and vasoconstrictor synthesized in the body from arachidonic acid. These receptors play a crucial role in various physiological processes, including platelet aggregation, smooth muscle contraction, and modulation of immune responses.

There are two main types of thromboxane receptors: TPα and TPβ. The TPα receptor is primarily found on platelets and vascular smooth muscle cells, while the TPβ receptor is expressed in various tissues such as the kidney, lung, and brain. Activation of these receptors by thromboxane A2 leads to a variety of cellular responses, including platelet activation and aggregation, vasoconstriction, and inflammation.

Abnormalities in thromboxane receptor function have been implicated in several pathological conditions, such as cardiovascular diseases, asthma, and cancer. Therefore, thromboxane receptors are an important target for the development of therapeutic agents to treat these disorders.

Vasopressin receptors are a type of G protein-coupled receptor that bind to and are activated by the hormone vasopressin (also known as antidiuretic hormone or ADH). There are two main types of vasopressin receptors, V1 and V2.

V1 receptors are found in various tissues throughout the body, including vascular smooth muscle, heart, liver, and kidney. Activation of V1 receptors leads to vasoconstriction (constriction of blood vessels), increased heart rate and force of heart contractions, and release of glycogen from the liver.

V2 receptors are primarily found in the kidney's collecting ducts. When activated, they increase water permeability in the collecting ducts, allowing for the reabsorption of water into the bloodstream and reducing urine production. This helps to regulate fluid balance and maintain normal blood pressure.

Abnormalities in vasopressin receptor function can contribute to various medical conditions, including hypertension, heart failure, and kidney disease.

Ketanserin is a medication that belongs to a class of drugs called serotonin antagonists. It works by blocking the action of serotonin, a neurotransmitter in the brain, on certain types of receptors. Ketanserin is primarily used for its blood pressure-lowering effects and is also sometimes used off-label to treat anxiety disorders and alcohol withdrawal syndrome.

It's important to note that ketanserin is not approved by the FDA for use in the United States, but it may be available in other countries as a prescription medication. As with any medication, ketanserin should only be used under the supervision of a healthcare provider and should be taken exactly as prescribed.

2-Amino-5-phosphonovalerate (APV) is a neurotransmitter receptor antagonist that is used in research to study the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors. These receptors are involved in various physiological processes, including learning and memory, and are also implicated in a number of neurological disorders. APV works by binding to the NMDA receptor and blocking its activity, which allows researchers to study the role of these receptors in different biological processes. It is not used as a therapeutic drug in humans.

Serotonin 5-HT4 receptor antagonists are a class of pharmaceutical drugs that block the action of serotonin at 5-HT4 receptors. Serotonin, also known as 5-hydroxytryptamine (5-HT), is a neurotransmitter involved in various physiological functions, including mood regulation, gastrointestinal motility, and cognition.

The 5-HT4 receptor is one of several subtypes of serotonin receptors found throughout the body, particularly in the brain, gastrointestinal tract, and cardiovascular system. These receptors are involved in regulating various physiological processes, including gastrointestinal motility, cognition, and mood regulation.

Serotonin 5-HT4 receptor antagonists work by binding to these receptors and preventing serotonin from activating them. This action can have various therapeutic effects, depending on the specific drug and its intended use. For example, some 5-HT4 receptor antagonists are used to treat gastrointestinal disorders such as irritable bowel syndrome (IBS) and gastroparesis, as they help slow down gastrointestinal motility and reduce symptoms such as diarrhea and abdominal pain.

Examples of 5-HT4 receptor antagonists include drugs such as alosetron, cisapride (now withdrawn from the market due to safety concerns), and prucalopride. These drugs are typically administered orally and have varying degrees of selectivity for the 5-HT4 receptor subtype.

It's important to note that while 5-HT4 receptor antagonists can have therapeutic effects, they can also have side effects, including constipation, nausea, and headache. Additionally, some of these drugs may interact with other medications or have potentially serious adverse effects, so it's essential to use them under the guidance of a healthcare professional.

Electric stimulation, also known as electrical nerve stimulation or neuromuscular electrical stimulation, is a therapeutic treatment that uses low-voltage electrical currents to stimulate nerves and muscles. It is often used to help manage pain, promote healing, and improve muscle strength and mobility. The electrical impulses can be delivered through electrodes placed on the skin or directly implanted into the body.

In a medical context, electric stimulation may be used for various purposes such as:

1. Pain management: Electric stimulation can help to block pain signals from reaching the brain and promote the release of endorphins, which are natural painkillers produced by the body.
2. Muscle rehabilitation: Electric stimulation can help to strengthen muscles that have become weak due to injury, illness, or surgery. It can also help to prevent muscle atrophy and improve range of motion.
3. Wound healing: Electric stimulation can promote tissue growth and help to speed up the healing process in wounds, ulcers, and other types of injuries.
4. Urinary incontinence: Electric stimulation can be used to strengthen the muscles that control urination and reduce symptoms of urinary incontinence.
5. Migraine prevention: Electric stimulation can be used as a preventive treatment for migraines by applying electrical impulses to specific nerves in the head and neck.

It is important to note that electric stimulation should only be administered under the guidance of a qualified healthcare professional, as improper use can cause harm or discomfort.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

A cannabinoid receptor, CB1, is a G protein-coupled receptor that is primarily found in the brain and central nervous system. It is one of the two main types of cannabinoid receptors, the other being CB2, and is activated by the endocannabinoid anandamide and the phytocannabinoid Delta-9-tetrahydrocannabinol (THC), which is the primary psychoactive component of cannabis. The activation of CB1 receptors is responsible for many of the psychological effects of cannabis, including euphoria, altered sensory perception, and memory impairment. CB1 receptors are also found in peripheral tissues, such as the adipose tissue, liver, and muscles, where they play a role in regulating energy metabolism, appetite, and pain perception.

Benzimidazoles are a class of heterocyclic compounds containing a benzene fused to a imidazole ring. They have a wide range of pharmacological activities and are used in the treatment of various diseases. Some of the benzimidazoles are used as antiparasitics, such as albendazole and mebendazole, which are effective against a variety of worm infestations. Other benzimidazoles have antifungal properties, such as thiabendazole and fuberidazole, and are used to treat fungal infections. Additionally, some benzimidazoles have been found to have anti-cancer properties and are being investigated for their potential use in cancer therapy.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

Dopamine D2 receptor is a type of metabotropic G protein-coupled receptor that binds to the neurotransmitter dopamine. It is one of five subtypes of dopamine receptors (D1-D5) and is encoded by the gene DRD2. The activation of D2 receptors leads to a decrease in the activity of adenylyl cyclase, which results in reduced levels of cAMP and modulation of ion channels.

D2 receptors are widely distributed throughout the central nervous system (CNS) and play important roles in various physiological functions, including motor control, reward processing, emotion regulation, and cognition. They are also involved in several neurological and psychiatric disorders, such as Parkinson's disease, schizophrenia, drug addiction, and Tourette syndrome.

D2 receptors have two main subtypes: D2 short (D2S) and D2 long (D2L). The D2S subtype is primarily located in the presynaptic terminals and functions as an autoreceptor that regulates dopamine release, while the D2L subtype is mainly found in the postsynaptic neurons and modulates intracellular signaling pathways.

Antipsychotic drugs, which are used to treat schizophrenia and other psychiatric disorders, work by blocking D2 receptors. However, excessive blockade of these receptors can lead to side effects such as extrapyramidal symptoms (EPS), tardive dyskinesia, and hyperprolactinemia. Therefore, the development of drugs that selectively target specific subtypes of dopamine receptors is an active area of research in the field of neuropsychopharmacology.

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.

Naltrexone is a medication that is primarily used to manage alcohol dependence and opioid dependence. It works by blocking the effects of opioids and alcohol on the brain, reducing the euphoric feelings and cravings associated with their use. Naltrexone comes in the form of a tablet that is taken orally, and it has no potential for abuse or dependence.

Medically, naltrexone is classified as an opioid antagonist, which means that it binds to opioid receptors in the brain without activating them, thereby blocking the effects of opioids such as heroin, morphine, and oxycodone. It also reduces the rewarding effects of alcohol by blocking the release of endorphins, which are natural chemicals in the brain that produce feelings of pleasure.

Naltrexone is often used as part of a comprehensive treatment program for addiction, along with counseling, behavioral therapy, and support groups. It can help individuals maintain abstinence from opioids or alcohol by reducing cravings and preventing relapse. Naltrexone is generally safe and well-tolerated, but it may cause side effects such as nausea, headache, dizziness, and fatigue in some people.

It's important to note that naltrexone should only be used under the supervision of a healthcare provider, and it is not recommended for individuals who are currently taking opioids or who have recently stopped using them, as it can cause withdrawal symptoms. Additionally, naltrexone may interact with other medications, so it's important to inform your healthcare provider of all medications you are taking before starting naltrexone therapy.

Intraventricular injections are a type of medical procedure where medication is administered directly into the cerebral ventricles of the brain. The cerebral ventricles are fluid-filled spaces within the brain that contain cerebrospinal fluid (CSF). This procedure is typically used to deliver drugs that target conditions affecting the central nervous system, such as infections or tumors.

Intraventricular injections are usually performed using a thin, hollow needle that is inserted through a small hole drilled into the skull. The medication is then injected directly into the ventricles, allowing it to circulate throughout the CSF and reach the brain tissue more efficiently than other routes of administration.

This type of injection is typically reserved for situations where other methods of drug delivery are not effective or feasible. It carries a higher risk of complications, such as bleeding, infection, or damage to surrounding tissues, compared to other routes of administration. Therefore, it is usually performed by trained medical professionals in a controlled clinical setting.

Adrenergic alpha-agonists are a type of medication that binds to and activates adrenergic alpha receptors, which are found in the nervous system and other tissues throughout the body. These receptors are activated naturally by chemicals called catecholamines, such as norepinephrine and epinephrine (also known as adrenaline), that are released in response to stress or excitement.

When adrenergic alpha-agonists bind to these receptors, they mimic the effects of catecholamines and cause various physiological responses, such as vasoconstriction (constriction of blood vessels), increased heart rate and force of heart contractions, and relaxation of smooth muscle in the airways.

Adrenergic alpha-agonists are used to treat a variety of medical conditions, including hypertension (high blood pressure), glaucoma, nasal congestion, and attention deficit hyperactivity disorder (ADHD). Examples of adrenergic alpha-agonists include phenylephrine, clonidine, and guanfacine.

It's important to note that adrenergic alpha-agonists can have both beneficial and harmful effects, depending on the specific medication, dosage, and individual patient factors. Therefore, they should only be used under the guidance of a healthcare professional.

Famotidine is a type of medication called an H2 blocker, or histamine-2 receptor antagonist. It works by reducing the amount of acid produced in the stomach. Famotidine is commonly used to treat and prevent ulcers in the stomach and intestines, and to manage conditions where the stomach produces too much acid, such as Zollinger-Ellison syndrome. It is also used to treat gastroesophageal reflux disease (GERD) and other conditions in which acid backs up from the stomach into the esophagus, causing heartburn.

Famotidine is available by prescription and over-the-counter in various forms, including tablets, capsules, and liquid. It is important to take famotidine exactly as directed by a healthcare professional, and to talk to them about any potential risks or side effects.

Neurokinin-2 (NK-2) receptors are a type of G protein-coupled receptor that binds to and is activated by the neuropeptide substance P, which is a member of the tachykinin family. These receptors are widely distributed in the central and peripheral nervous systems and play important roles in various physiological functions, including pain transmission, smooth muscle contraction, and neuroinflammation.

NK-2 receptors are involved in the development of hyperalgesia (an increased sensitivity to pain) and allodynia (pain caused by a stimulus that does not normally provoke pain). They have also been implicated in several pathological conditions, such as inflammatory bowel disease, asthma, and neurodegenerative disorders.

NK-2 receptor antagonists have been developed and investigated for their potential therapeutic use in the treatment of various pain disorders, gastrointestinal diseases, and other medical conditions.

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.

Bradykinin is a naturally occurring peptide in the human body, consisting of nine amino acids. It is a potent vasodilator and increases the permeability of blood vessels, causing a local inflammatory response. Bradykinin is formed from the breakdown of certain proteins, such as kininogen, by enzymes called kininases or proteases, including kallikrein. It plays a role in several physiological processes, including pain transmission, blood pressure regulation, and the immune response. In some pathological conditions, such as hereditary angioedema, bradykinin levels can increase excessively, leading to symptoms like swelling, redness, and pain.

Cannabinoid receptor antagonists are a class of compounds that bind to and block cannabinoid receptors, which are specialized proteins found on the surface of certain cells in the body. These receptors play an important role in regulating various physiological processes, including pain perception, appetite regulation, and memory formation.

There are two main types of cannabinoid receptors: CB1 receptors, which are primarily found in the brain and central nervous system, and CB2 receptors, which are mainly found in immune cells and other peripheral tissues.

Cannabinoid receptor antagonists work by preventing the activation of these receptors by natural cannabinoids such as THC (tetrahydrocannabinol), the main psychoactive component of marijuana. By blocking the effects of THC, cannabinoid receptor antagonists can be used to treat conditions that are exacerbated by THC, such as substance use disorders and psychosis.

One example of a cannabinoid receptor antagonist is rimonabant, which was approved in Europe for the treatment of obesity but was later withdrawn from the market due to concerns about psychiatric side effects. Other cannabinoid receptor antagonists are currently being investigated for their potential therapeutic uses, including the treatment of pain, inflammation, and neurodegenerative disorders.

Naloxone is a medication used to reverse the effects of opioids, both illicit and prescription. It works by blocking the action of opioids on the brain and restoring breathing in cases where opioids have caused depressed respirations. Common brand names for naloxone include Narcan and Evzio.

Naloxone is an opioid antagonist, meaning that it binds to opioid receptors in the body without activating them, effectively blocking the effects of opioids already present at these sites. It has no effect in people who have not taken opioids and does not reverse the effects of other sedatives or substances.

Naloxone can be administered via intranasal, intramuscular, intravenous, or subcutaneous routes. The onset of action varies depending on the route of administration but generally ranges from 1 to 5 minutes when given intravenously and up to 10-15 minutes with other methods.

The duration of naloxone's effects is usually shorter than that of most opioids, so multiple doses or a continuous infusion may be necessary in severe cases to maintain reversal of opioid toxicity. Naloxone has been used successfully in emergency situations to treat opioid overdoses and has saved many lives.

It is important to note that naloxone does not reverse the effects of other substances or address the underlying causes of addiction, so it should be used as part of a comprehensive treatment plan for individuals struggling with opioid use disorders.

Quinuclidines are a class of organic compounds that contain a unique cage-like structure consisting of a tetrahydrofuran ring fused to a piperidine ring. The name "quinuclidine" is derived from the Latin word "quinque," meaning five, and "clidis," meaning key or bar, which refers to the five-membered ring system that forms the core of these compounds.

Quinuclidines have a variety of biological activities and are used in pharmaceuticals as well as agrochemicals. Some quinuclidine derivatives have been found to exhibit anti-inflammatory, antiviral, and anticancer properties. They can also act as inhibitors of various enzymes and receptors, making them useful tools for studying biological systems and developing new drugs.

It is worth noting that quinuclidines are not typically used in medical diagnosis or treatment, but rather serve as building blocks for the development of new pharmaceutical compounds.

Benzodiazepines are a class of psychoactive drugs that possess anxiolytic, anticonvulsant, amnesic, sedative, hypnotic, and muscle relaxant properties. Benzodiazepinones are a subclass of benzodiazepines that share a specific chemical structure, characterized by a 1,4-benzodiazepine ring with an additional nitrogen-containing ring attached at the 2-position of the benzodiazepine ring.

Examples of benzodiazepinones include clonazepam (Klonopin), diazepam (Valium), and flurazepam (Dalmane). These medications are commonly used in the treatment of anxiety disorders, insomnia, seizures, and muscle spasms. However, they can also cause physical dependence and withdrawal symptoms, so they should be prescribed with caution and under medical supervision.

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.

Adrenergic beta-2 receptor antagonists, also known as beta-2 adrenergic blockers or beta-2 antagonists, are a class of medications that block the action of epinephrine (adrenaline) and other catecholamines at beta-2 adrenergic receptors. These receptors are found in various tissues throughout the body, including the lungs, blood vessels, and skeletal muscles.

Beta-2 adrenergic receptor antagonists are primarily used to treat respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). They work by relaxing the smooth muscle in the airways, which helps to reduce bronchoconstriction and improve breathing.

Some examples of beta-2 adrenergic receptor antagonists include:

* Butoxamine
* ICI 118,551
* Salbutamol (also a partial agonist)
* Terbutaline (also a partial agonist)

It's important to note that while these medications are called "antagonists," some of them can also act as partial agonists at beta-2 receptors, meaning they can both block the action of catecholamines and stimulate the receptor to some degree. This property can make them useful in certain clinical situations, such as during an asthma attack or preterm labor.

Bicuculline is a pharmacological agent that acts as a competitive antagonist at GABA-A receptors, which are inhibitory neurotransmitter receptors in the central nervous system. By blocking the action of GABA (gamma-aminobutyric acid) at these receptors, bicuculline can increase neuronal excitability and cause convulsions. It is used in research to study the role of GABAergic neurotransmission in various physiological processes and neurological disorders.

Nicotinic receptors are a type of ligand-gated ion channel receptor that are activated by the neurotransmitter acetylcholine and the alkaloid nicotine. They are widely distributed throughout the nervous system and play important roles in various physiological processes, including neuronal excitability, neurotransmitter release, and cognitive functions such as learning and memory. Nicotinic receptors are composed of five subunits that form a ion channel pore, which opens to allow the flow of cations (positively charged ions) when the receptor is activated by acetylcholine or nicotine. There are several subtypes of nicotinic receptors, which differ in their subunit composition and functional properties. These receptors have been implicated in various neurological disorders, including Alzheimer's disease, Parkinson's disease, and schizophrenia.

Imidazoles are a class of heterocyclic organic compounds that contain a double-bonded nitrogen atom and two additional nitrogen atoms in the ring. They have the chemical formula C3H4N2. In a medical context, imidazoles are commonly used as antifungal agents. Some examples of imidazole-derived antifungals include clotrimazole, miconazole, and ketoconazole. These medications work by inhibiting the synthesis of ergosterol, a key component of fungal cell membranes, leading to increased permeability and death of the fungal cells. Imidazoles may also have anti-inflammatory, antibacterial, and anticancer properties.

Interleukin-1 alpha (IL-1α) is a member of the interleukin-1 cytokine family, which plays a crucial role in the regulation of inflamation and immune responses. IL-1α is primarily produced by activated macrophages, epithelial cells, and fibroblasts. It is a potent proinflammatory cytokine that binds to the interleukin-1 receptor (IL-1R) and activates signaling pathways leading to the expression of genes involved in inflammation, fever, and cellular activation. IL-1α is involved in various physiological processes such as hematopoiesis, bone remodeling, and response to infection or injury. Dysregulation of IL-1α has been implicated in several pathological conditions including autoimmune diseases, atherosclerosis, and cancer.

Mineralocorticoid receptor antagonists (MRAs) are a class of medications that block the action of aldosterone, a hormone produced by the adrenal glands. Aldosterone helps regulate sodium and potassium balance and blood pressure by binding to mineralocorticoid receptors in the kidneys, heart, blood vessels, and brain.

When aldosterone binds to these receptors, it promotes sodium retention and potassium excretion, which can lead to an increase in blood volume and blood pressure. MRAs work by blocking the binding of aldosterone to its receptors, thereby preventing these effects.

MRAs are primarily used to treat heart failure, hypertension, and kidney disease. By reducing sodium retention and increasing potassium excretion, MRAs can help lower blood pressure, reduce fluid buildup in the body, and improve heart function. Examples of MRAs include spironolactone and eplerenone.

Histamine H3 receptors are a type of G protein-coupled receptor (GPCR) that are widely distributed throughout the central and peripheral nervous system. They are activated by the neurotransmitter histamine and function as autoreceptors, inhibiting the release of histamine from presynaptic nerve terminals. Histamine H3 receptors also modulate the activity of other neurotransmitters, such as acetylcholine, dopamine, norepinephrine, and serotonin, by regulating their synthesis, release, and uptake.

Histamine H3 receptors have been identified as potential targets for the treatment of various neurological and psychiatric disorders, including sleep disorders, attention deficit hyperactivity disorder (ADHD), schizophrenia, and drug addiction. Antagonists or inverse agonists of Histamine H3 receptors may enhance the release of neurotransmitters in the brain, leading to improved cognitive function, mood regulation, and reward processing. However, further research is needed to fully understand the therapeutic potential and safety profile of Histamine H3 receptor modulators.

Blood pressure is the force exerted by circulating blood on the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and is given as two figures:

1. Systolic pressure: This is the pressure when the heart pushes blood out into the arteries.
2. Diastolic pressure: This is the pressure when the heart rests between beats, allowing it to fill with blood.

Normal blood pressure for adults is typically around 120/80 mmHg, although this can vary slightly depending on age, sex, and other factors. High blood pressure (hypertension) is generally considered to be a reading of 130/80 mmHg or higher, while low blood pressure (hypotension) is usually defined as a reading below 90/60 mmHg. It's important to note that blood pressure can fluctuate throughout the day and may be affected by factors such as stress, physical activity, and medication use.

Yohimbine is defined as an alkaloid derived from the bark of the Pausinystalia yohimbe tree, primarily found in Central Africa. It functions as a selective antagonist of α2-adrenergers, which results in increased noradrenaline levels and subsequent vasodilation, improved sexual dysfunction, and potentially increased energy and alertness.

It is used in traditional medicine for the treatment of erectile dysfunction and as an aphrodisiac, but its efficacy and safety are still subjects of ongoing research and debate. It's important to note that yohimbine can have significant side effects, including anxiety, increased heart rate, and high blood pressure, and should only be used under the supervision of a healthcare professional.

Opioid receptors are a type of G protein-coupled receptor (GPCR) found in the cell membranes of certain neurons in the central and peripheral nervous system. They bind to opioids, which are chemicals that can block pain signals and produce a sense of well-being. There are four main types of opioid receptors: mu, delta, kappa, and nociceptin. These receptors play a role in the regulation of pain, reward, addiction, and other physiological functions. Activation of opioid receptors can lead to both therapeutic effects (such as pain relief) and adverse effects (such as respiratory depression and constipation).

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... (INN) is an α1-adrenergic receptor antagonist. Bunazosin was initially developed to treat benign prostatic ... Systemic Alpha-1 adrenergic receptor antagonists have been implicated in Intraoperative Floppy Iris Syndrome (IFIS). Bunazosin ... Alpha blockers, Carboxamides, Catechol ethers, Diazepanes, Quinazolines, All stub articles, Antihypertensive agent stubs). ...
Angiotensin receptor blockers (ARB) and calcium channel blockers (CCB), alpha- and beta- adrenergic receptor blockers ... Drugs that act as selective antagonists at specific alpha-1 adrenergic receptor subtypes have also been developed. Benign ... Silodosin shows high affinity and selectivity for alpha-1a adrenergic receptors found in the prostate which ensures that it ... DrugDigest - Alpha blockers RxList.com - Tamsulosin alpha-Adrenergic+Blockers at the U.S. National Library of Medicine Medical ...
It features competitive antagonist activity at 5-HT serotonin receptor in Sprague-Dawley rat stomachs. It exhibits binding ... It was found to be an active Alpha-1 adrenergic receptor agonist in rabbit ear arteries. It has binding affinity towards 5-HT2C ... 2C-H exhibits agonist activity in vitro at human trace amine associated receptor 1 expressed in RD-HGA16 CHO-K1 cells ... affinity against rat 5-hydroxytryptamine 2C receptors using [3H]mesulergine as a radioligand. As of October 31, 2016; 2C-H is a ...
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Irreversible antagonists, Kappa-opioid receptor antagonists, Phenols, Semisynthetic opioids, Tertiary alcohols, All stub ... GNTI has been found to act as a positive allosteric modulator of the α1A-adrenergic receptor (EC50 = 41 nM), and this may ... Alpha-1 adrenergic receptor agonists, Guanidines, Indolomorphinans, ... Obara I, Mika J, Schafer MK, Przewlocka B (October 2003). "Antagonists of the kappa-opioid receptor enhance allodynia in rats ...
Additionally, l-THP displays significant binding to 5-HT1A and alpha-2 adrenergic receptors. In the case of 5-HT1A receptors, l ... D1 antagonists, D2 antagonists, Dopamine receptor modulators, GABAA receptor positive allosteric modulators, Ion channel ... alpha adrenergic and serotonin receptors. The Ki values for l-THP at D1 and D2 dopamine receptors are approximately 124 nM (D1 ... Along with dopamine receptors, l-THP has been reported to interact with a number of other receptor types, including alpha-1 ...
... is a drug used in benign prostatic hypertrophy which acts as a selective α1-adrenergic receptor antagonist or alpha-1 blocker. ... Alpha-1 blockers, Antihypertensive agents, Calcium channel blockers, N-(2-methoxyphenyl)piperazines, Naphthol ethers, ... 57 (1): 7-13. PMID 21304253. v t e (Articles with short description, Short description matches Wikidata, Drugs not assigned an ...
Alpha 2 blockers Alpha 2 blockers inhibit the activation of adenylyl cyclase via Gi protein by antagonising alpha 2 receptors, ... Adrenergic neurone blockers, commonly known as adrenergic antagonists, are a group of drugs that inhibit the sympathetic ... Selective alpha 2 blockers The possibility for selective alpha 2 blockers to interact with non-target receptors, such as 5-HT ... Taylor, Bryce N.; Cassagnol, Manouchkathe (2023), "Alpha Adrenergic Receptors", StatPearls, Treasure Island (FL): StatPearls ...
Administering a norepinephrine receptor agonist (a substance that initiates a cell response when it binds with a receptor) to ... Noradrenergic antagonists were not prescribed for the purposes of slowing the recovery of memory. Rather, these findings are ... The alpha-1 adrenergic receptor is specifically implicated. Although it has not yet been thoroughly investigated, there is ... Conversely, the administration of norepinephrine antagonists slowed recovery, and could lead to the reinstatement of deficits ...
This drug is a non-selective α-adrenergic antagonist, which means it binds to both alpha receptors. There were few if any ... An adrenergic antagonist is a drug that inhibits the function of adrenergic receptors. There are five adrenergic receptors, ... Adrenergic competitive antagonists are shorter lasting than the other two types of antagonists. While the antagonists for alpha ... There are few non-cardiovascular uses for adrenergic antagonists. Alpha-adrenergic antagonists are also used for treatment of ...
GnRH receptor agonists, such as leuprorelin and goserelin, were subsequently developed and used to treat prostate cancer. ... In general, treatment often begins with an alpha-1 adrenergic receptor antagonist medication such as tamsulosin, which reduces ... This is often done through the use of GnRH analogues or agents (such as bicalutamide) that block the receptors that androgens ... or male chronic pelvic pain syndrome is treated by a large variety of modalities including the medications alpha blockers, ...
Cleary L, Murad K, Bexis S, Docherty JR (2005). "The alpha (1D)-adrenoceptor antagonist BMY 7378 is also an alpha (2C)- ... The alpha-2C adrenergic receptor (α2C adrenoceptor), also known as ADRA2C, is an alpha-2 adrenergic receptor, and also denotes ... "Human alpha 2-adrenergic receptor subtype distribution: widespread and subtype-selective expression of alpha 2C10, alpha 2C4, ... "Entrez Gene: ADRA2C adrenergic, alpha-2C-, receptor". "ADRA2C adrenoceptor alpha 2C [Homo sapiens (human)] - Gene - NCBI". www. ...
... is a compound which acts as an antagonist at the α1B-adrenergic receptor. It was one of the first selective antagonists ... April 1998). "Search for selective antagonists at alpha 1-adrenoreceptors: neutral or negative antagonism?". Farmaco. 53 (4): ... developed for this receptor and was invented in 1969, but is still commonly used in research into adrenergic receptors, ... March 2000). "Alpha 1-adrenoreceptor antagonists bearing a quinazoline or a benzodioxane moiety". Pharmaceutica Acta Helvetiae ...
ISBN 978-0-443-06911-6. Alpha receptors illustrated The Adrenergic Receptors Adrenoceptors - IUPHAR/BPS guide to pharmacology ... "Functional studies of the first selective beta 3-adrenergic receptor antagonist SR 59230A in rat brown adipocytes". Molecular ... Beta adrenergic receptor kinase Beta adrenergic receptor kinase-2 There is no α1C receptor. There was a subtype known as C, but ... and β-Adrenergic Receptors Theory of receptor activation Desensitization of β1 receptors (Webarchive template wayback links, ...
However, the most common type of alpha blocker is usually an α1 blocker. Non-selective α-adrenergic receptor antagonists ... are a class of pharmacological agents that act as antagonists on α-adrenergic receptors (α-adrenoceptors). Historically, alpha- ... "Alpha-Adrenoceptor Antagonists (Alpha-Blockers)" (PDF). British Hypertension Society. Archived from the original (PDF) on 2017- ... "CV Pharmacology , Alpha-Adrenoceptor Antagonists (Alpha-Blockers)". cvpharmacology.com. Retrieved 2017-11-15. Knott, Laurence ( ...
... has been shown to interact with Src. Other adrenergic receptors Alpha-1 adrenergic receptor Alpha-2 ... Nisoli E, Tonello C, Landi M, Carruba MO (1996). "Functional studies of the first selective β3-adrenergic receptor antagonist ... The beta-3 adrenergic receptor (β3-adrenoceptor), also known as ADRB3, is a beta-adrenergic receptor, and also denotes the ... adrenergic receptor antagonists". The Journal of Pharmacology and Experimental Therapeutics. 290 (2): 649-55. PMID 10411574. ...
... seventh hydrophobic domain of the alpha 2 adrenergic receptor increases its affinity for a family of beta receptor antagonists ... The alpha-2A adrenergic receptor (α2A adrenoceptor), also known as ADRA2A, is an α2 adrenergic receptor, and also denotes the ... the sites for beta-adrenergic receptor kinase-mediated phosphorylation and desensitization of the alpha 2A-adrenergic receptor ... alpha-2A-, receptor". Hein, Lutz; Altman, John D.; Kobilka, Brian K. (1999). "Two functionally distinct α2-adrenergic receptors ...
... denotes selective antagonist to the receptor. compound-6FA, PAM at intracellular binding site Beta-2 adrenergic receptor has ... Other adrenergic receptors Alpha-1 adrenergic receptor Alpha-2 adrenergic receptor Beta-1 adrenergic receptor Beta-3 adrenergic ... The beta-2 adrenergic receptor (β2 adrenoreceptor), also known as ADRB2, is a cell membrane-spanning beta-adrenergic receptor ... "Insulin stimulates sequestration of beta-adrenergic receptors and enhanced association of beta-adrenergic receptors with Grb2 ...
See also receptor antagonist) alpha-2 receptors. Agonists of alpha-2 receptors in the vascular smooth muscle lead to ... alpha-2 and beta-2 adrenergic receptors,. The main endogenous agonist of these cell receptors is norepinephrine (NE). The ... adrenergic receptors exert opposite physiologic effects in the vascular smooth muscle under activation: alpha-1 receptors. ... Antagonists of alpha-1 receptors (doxazosin, prazosin) cause vasodilation (a decrease in vascular smooth muscle tone with ...
... is an α1-adrenergic receptor antagonist. Alpha blocker Tham TC, Guy S, Shanks RG, Harron DW (April 1992). "Dose-dependent alpha ... Alpha-1 blockers, Quinolines, Norsalsolinol ethers, All stub articles, Antihypertensive agent stubs, Genito-urinary system drug ... 1-adrenoceptor antagonist activity of the anti-arrhythmic drug, abanoquil (UK-52,046), without reduction in blood pressure in ...
Day HE, Campeau S, Watson SJ, Akil H (July 1997). "Distribution of alpha 1a-, alpha 1b- and alpha 1d-adrenergic receptor mRNA ... Prazosin has been said to be the only selective α1-adrenergic receptor antagonist which has been used in the treatment of ... 13-398 nM for the α2B-adrenergic receptor, and 10-200 nM for the α2C-adrenergic receptor). The α1-adrenergic receptors are ... It has much lower affinity for the α2-adrenergic receptors (Ki = 210-5,012 nM for the α2A-adrenergic receptor, ...
Agonist and antagonist properties at subtypes of dopamine D(2)-like receptor and alpha(1)/alpha(2)-adrenoceptor". J Pharmacol ... It also interacts with other dopamine receptors and with various serotonin and adrenergic receptors. Bromocriptine has ... As an antagonist of the serotonin 5-HT2B receptor, bromocriptine has not been associated with cardiac valvulopathy. This is in ... "Differential actions of antiparkinson agents at multiple classes of monoaminergic receptor. III. Agonist and antagonist ...
Other adrenergic receptors Alpha-1 adrenergic receptor Alpha-2 adrenergic receptor Beta-2 adrenergic receptor Beta-3 adrenergic ... or one of the four adrenergic receptors. It is a G-protein coupled receptor associated with the Gs heterotrimeric G-protein ... and beta 2-adrenergic receptors: structurally and functionally related receptors derived from distinct genes". Trends in ... Dong Q, Ptáček LJ, Fu YH (April 2023). "Mutant β1-adrenergic receptor improves REM sleep and ameliorates tau accumulation in a ...
... is a calcium channel blocker and α1-adrenergic receptor antagonist used as an antihypertensive. Sugimoto T, Hosoki K ... Karasawa T (July 1995). "Relative contribution of alpha 1-adrenoceptor blocking activity to the hypotensive effect of the novel ... Alpha-1 blockers, Calcium channel blockers, Carboxamides, Dibenzothiepines, Fluoroarenes, Phenylpiperazines, All stub articles ... 26 (1): 55-60. doi:10.1097/00005344-199507000-00009. PMID 7564365. S2CID 1548014. v t e (Articles without EBI source, Articles ...
Antagonists A-315456 BMY 7378 (also α2C antagonist) Adrenergic receptor GRCh38: Ensembl release 89: ENSG00000171873 - Ensembl, ... This gene encodes alpha-1D-adrenergic receptor. Similar to alpha-1B-adrenergic receptor gene, this gene comprises 2 exons and a ... 1994). "Cloning, expression and characterization of human alpha adrenergic receptors alpha 1a, alpha 1b and alpha 1c". Biochem ... The alpha-1D adrenergic receptor (α1D adrenoreceptor), also known as ADRA1D, is an alpha-1 adrenergic receptor, and also ...
... is a calcium channel blocker and α1-adrenergic receptor antagonist. Boer R, Grassegger A, Schudt C, Glossmann H ( ... Niguldipine binds with very high affinity to Ca2+ channels and to a subtype of alpha 1-adrenoceptors". European Journal of ... Alpha-1 blockers, Calcium channel blockers, Carboxylate esters, Dihydropyridines, Nitrobenzenes, All stub articles, ...
... also acts as a moderate affinity 5-HT1A receptor antagonist, and low affinity CB1 receptor antagonist). Clonidine (also I1 ... For example, the alpha-2A adrenergic receptor subtype is post-synaptic in the prefrontal cortex and these receptors strengthen ... The alpha-2 (α2) adrenergic receptor (or adrenoceptor) is a G protein-coupled receptor (GPCR) associated with the Gi ... signal through the α2-adrenergic receptor in the central and peripheral nervous systems. The α2A adrenergic receptor is ...
BMY-7,378 is a 5-HT1A receptor weak partial agonist/antagonist and α1D-adrenergic receptor antagonist. Goetz AS, King HK, Ward ... "BMY 7378 is a selective antagonist of the D subtype of alpha 1-adrenoceptors". European Journal of Pharmacology. 272 (2-3): R5- ...
Silodosin, is an alpha-adrenoreceptor antagonist. It works by blocking receptors called alpha1A adrenoreceptors in the prostate ... Silodosin has high affinity for the α1A adrenergic receptor in the prostate, the bladder, and the prostatic urethra. By this ... Intra operative floppy iris syndrome occurs in some people taking alpha adrenoreceptor antagonists and may lead to ... By blocking these receptors, silodosin allows these muscles to relax, making it easier to pass urine and relieving the symptoms ...
Nonselective alpha-1 and alpha-2 adrenergic antagonist. Reversibly binds to alpha-1 adrenergic receptors on the iris dilator ... Indicated for treatment of pharmacologically-induced mydriasis produced by adrenergic agonists (eg, phenylephrine) or ... and indirectly reverses mydriasis induced by muscarinic antagonist effects on the iris sphincter muscle ... Indicated for treatment of pharmacologically-induced mydriasis produced by adrenergic agonists (eg, phenylephrine) or ...
Current or past use of medicinal products with alpha 1a-adrenergic antagonist effect should be made known to the ophthalmic ... H1-histaminergic and alpha 2-adrenergic receptors. The pharmacological activity of the (+)- and (-)-paliperidone enantiomers ... has been observed during cataract surgery in patients treated with medicinal products with alpha 1a-adrenergic antagonist ... Paliperidone is not bound to cholinergic receptors. Even though paliperidone is a strong D2-antagonist, which is believed to ...
BACKGROUND: An association between adrenergic alpha-1 receptor antagonists and delirium has been suggested, but the details are ... Anticholinergics or beta3-adrenergic receptor agonists to treat overactive bladder in patients receiving tamsulosin and ... AIM: This study investigated the association between adrenergic alpha-1 receptor antagonists and delirium in patients with ... Next, multivariate logistic analysis was performed to examine the association between delirium and adrenergic alpha-1 receptor ...
... alpha 2-adrenergic receptor in vitro: Yohimbine inhibits alpha2-receptor antagonist with Ki of 1.05 nM, 1.19 nM, and 1.19 nM ... antagonist, with IC50 of 0.6 μM. IC50 value: 0.6 uM [1] Target: ... Yohimbine is a potent and relatively nonselective alpha 2- ... Target: alpha 2-adrenergic receptor. in vitro: Yohimbine inhibits alpha2-receptor antagonist with Ki of 1.05 nM, 1.19 nM, and ... Activator Antagonist Antagonist,Activator Antagonist,Agonist Antagonist,Inducer Antagonist,Inhibitor Antagonist,Inhibitor, ...
The enhanced sensitivity to alpha-adrenergic receptor blockade following TiO2 exposure suggests an augmented responsiveness to ... an alpha-adrenergic antagonist (1 microM), reduced sympathetic constriction in controls, but abolished this response in TiO2 ... Nanoparticle inhalation modulates arteriolar sympathetic constriction: role of nitric oxide, prostanoids, and alpha-adrenergic ...
... serotonin receptors. Trazodone is also an antagonist at several other monoaminergic receptors including 5-HT2B (Ki = 78.4 nM), ... Trazodone antagonizes alpha 1-adrenergic receptors, a property which may be associated with postural hypotension. ... Trazodone is both a selective serotonin reuptake inhibitor (SSRI) and a 5HT2 receptor antagonist and the net result of this ... a selective serotonin reuptake inhibitor and 5HT2 receptor antagonist. Trazodone hydrochloride is a triazolopyridine derivative ...
Surprisingly, beta-blockers, unlike alpha-blockers, appear to impair sleep.. beta-blocker beta-adrenergic receptor beta- ... beta blocker antagonist adrenaline adrenergic blood pressure hypertension heart rate. *melatonin deep sleep quality ... Prediction of sleep disorders induced by beta-adrenergic receptor blocking agents based on receptor occupancy. - PubMed - NCBI ... Turnover of adrenergic receptors under normal and desensitized conditions. - PubMed - NCBI 1 ...
The effect of adrenergic receptor antagonists on cocaine-induced ventricular fibrillation: alpha but not beta adrenergic ... In one study, when the heart rate is held constant, alpha-adrenergic but not beta-adrenergic receptor antagonists prevented ... Cocaine activation of myocardial alpha-adrenergic receptors, specifically alpha1A-adrenergic receptors, may substantially ... Epinephrine has been the drug of choice for the treatment of cardiac arrest, primarily for its alpha-adrenergic effects. ...
Arylpiperazinyl) cyclohexyl sufonamides: Discovery of α1a/1d-selective adrenergic receptor antagonists for the treatment of ... Comparison of effects of alpha receptor blockers on endothelial functions and coagulation parameters in patients with benign ... de Reijke TM, Klarskov P. Comparative efficacy of two alpha-adrenoreceptor antagonists, doxazosin and alfuzosin, in patients ... Impact of alpha 1-adrenergic antagonist use for benign prostatic hypertrophy on outcomes in patients with heart failure. The ...
ADRENERGIC BETA-ANTAGONISTS; ADRENERGIC ALPHA-ANTAGONISTS; ANGIOTENSIN-CONVERTING ENZYME INHIBITORS; CALCIUM CHANNEL BLOCKERS; ... The AM1 receptor is composed of the calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 2 (RAMP2), ... The CGRP receptor is a complex of two proteins: calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein ... AdrenomedullinReceptors, AdrenomedullinCalcitonin Receptor-Like ProteinPeptidesReceptor Activity-Modifying Protein 2Receptor ...
Mirtazapine is a 5-HT antagonist and blocks alpha-2 adrenergic autoreceptors, as well as 5-HT2 and 5-HT3 receptors. The result ... Agomelatine is a melatonergic (MT1/MT2) agonist and a 5-HT2C receptor antagonist that is taken at bedtime. It is used for major ... and alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptors, leads to rapid increases in dendritic spine ... but they also stimulate 5-HT2 receptors, commonly causing anxiety, insomnia, and sexual dysfunction, and 5-HT3 receptors, ...
Alpha-adrenergic antagonists (phentolamine) are the preferred agents for cocaine-associated acute coronary syndromes. [29] ... 21] Hypertensive women who become pregnant should not be treated with ACEIs, angiotensin-receptor blockers (ARBs), or direct ... Barry E Brenner, MD, PhD, FACEP is a member of the following medical societies: Alpha Omega Alpha, American Academy of ... Labetalol, an alpha- and beta-blocking agent, has proven to be quite beneficial in the treatment of patients with hypertensive ...
Currently alpha adrenergic receptor antagonists ( to relieve the muscle spasm) & steroids ( to reduce oedema) are being used as ... one adrenergic antagonist can inhibit the basal tone of Address for correspondence: Dr. Brijesh Kumar Agarwal, Associate ... Yelman et al (14) compared the efficacy of three Alpha adrenergic blocker like tamsulosin is a drug of different alfa blockers ... Medical expulsive therapy is an mucosal oedema . Alfa one adrenergic receptors are established treatment for lower ureteric ...
Pseudoephedrine is both an alpha-and beta-adrenergic receptor agonist. It causes vasoconstriction via direct stimulation of ... Triprolidine hydrochloride is a potent competitive histamine H1-receptor antagonist with antimuscarinic and mild sedative ... alpha-adrenergic receptors of the respiratory mucosa. It also directly stimulates beta-adrenergic receptors causing bronchial ... Bretylium, bethanidine, guanethidine, debrisoquine, methyldopa, alpha- & beta-adrenergic blocker; furazolidone, alcohol, ...
Beta-3 adrenergic receptor. Mirabegron was approved in 2012 by the US Food and Drug Administration (FDA) for the treatment of ... It has alpha-adrenergic effect on the bladder neck and antispasmodic effect on detrusor muscle. Imipramine hydrochloride has a ... Tolterodine L-tartrate is a competitive muscarinic receptor antagonist for overactive bladder. It differs from other ... Antimuscarinics, beta-3 adrenergic receptor agonists, or a combination of both may be used to improve bladder storage ...
Alpha-1B adrenergic receptor 17. *Alpha-1A adrenergic receptor 17. *Histamine H3 receptor 17 ... Affinity DataKi: 1.20nMAssay Description:Antagonist activity at human Histamine H1 receptor expressed in CHO cells assessed as ... Affinity DataKi: 0.251nMAssay Description:Antagonist activity at human Histamine H3 receptor expressed in CHO cell membranes ... Affinity DataKi: 0.316nMAssay Description:Antagonist activity at human Histamine H3 receptor expressed in CHO cell membranes ...
The alpha 1C-adrenergic receptor: characterization of signal transduction pathways and mammalian tissue heterogeneity. D A ... Alpha-naphthoflavone acts as an antagonist of 2,3,7, 8-tetrachlorodibenzo-p-dioxin by forming an inactive complex with the Ah ... Molecular interaction of the human alpha 2-C10-adrenergic receptor, when expressed in Rat-1 fibroblasts, with multiple ... Prostaglandin receptors in NIH 3T3 cells: coupling of one receptor to adenylate cyclase and of a second receptor to ...
Ergot alkaloid and alpha adrenergic receptor antagonist with vasoconstrictor effect which is less effective than ergotamine. ... Ergot alkaloid and alpha adrenergic receptor antagonist with vasoconstrictor effect which is less effective than ergotamine. ...
Promethazine: Antidopaminergic effect due to blocking mesolimbic dopamine receptors and alpha-adrenergic receptors in the brain ... an opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate ... antihistaminic effect due to blocking H1-receptors. Codeine: Narcotic agonist analgesic with antitussive activity, mu receptor ... 10% of codeine is metabolized to morphine by CYP2D6; the active morphine metabolite has a higher affinity for opioid receptors ...
alpha 2a-adrenergic. *alpha 2b-adrenergic. *alpha 2c-adrenergic. *A1 adenosine. *A3 adenosine ... Since desensitization only occurs with an activated receptor, monitoring beta-arrestin translocation and subsequent receptor ... including agonists or antagonists. The Transfluor Assay requires no prior knowledge of the interacting G-protein, making it ... the location of the receptor-arrestin complex may be monitored during receptor activation. ...
... "alpha-adrenergic agonists" EXACT [] synonym: "alpha-adrenergic receptor agonist" EXACT [] synonym: "alpha-adrenoceptor agonists ... "adrenergic receptor antagonist" EXACT [] is_a: XCO:0000160 ! receptor antagonist created_by: jsmith creation_date: 2013-08- ... alpha-adrenergic agonist alt_id: CHEBI:35569 def: "An agent that selectively binds to and activates alpha-adrenergic receptors ... "beta-adrenergic agonists" EXACT [] synonym: "beta-adrenergic receptor agonist" EXACT [] synonym: "beta-adrenergic receptor ...
Receptors implicated in clinical response and adverse effects include dopamine D2, serotonin 5HT1A and 5HT2A, as well as H1 ... a. the development of long acting opiate antagonists (naltrexone) and partial agonist (buprenorphine) to improve treatment ... Varying receptor affinities can explain the clinical profile specific to each compound, including adverse events such as weight ... Receptor profiles also play a role when switching between antipsychotics. Consideration of the differences between agents being ...
Yohimbine is an alpha receptor antagonist. Alpha receptors reduce fat burning, so when you combine a alpha receptor antagonist ... and alpha adrenergic antagonists (Yohimbine HCl), all to add the T3 characteristics of increase the metabolic rate by ... and alpha adrenergic antagonists (Yohimbine HCl), all to add the T3 characteristics of increase the metabolic rate by ... CYX3 (an oral blend of T3, Yohimbine and Clenbuterol) Combines the synergistic fat burning power of beta adrenergic agonists) ...
The drugs approved for BPH include 5α-reductase inhibitors (5-ARIs), alpha1-adrenergic antagonists (α1-blockers), ... DHT binds to androgen receptor (AR) with higher affinity than does testosterone [5]. AR is a type of nuclear receptor that ... Lowe, F. Alpha-1-adrenoceptor blockade in the treatment of benign prostatic hyperplasia. Prostate Cancer Prostatic. Dis. 1999, ... Vickman, R.E.; Franco, O.E.; Moline, D.C.; Vander Griend, D.J.; Thumbikat, P.; Hayward, S.W. The role of the androgen receptor ...
Xylometazoline works by binding to alpha (α)-adrenergic receptors to cause vasoconstriction of nasal blood vessels. ... Matched Synonyms: … 72 amino acid proprietary recombinant protein antagonist for the CXCR1 and CXCR2 receptors of interleukin ... MM-111 is a novel bispecific antibody fusion protein that co-targets the the epidermal growth factor family receptor tyrosine ... Matched Description: … fusion protein that co-targets the the epidermal growth factor family receptor tyrosine kinases, ERBB2 ...
Ziprasidone functioned as an antagonist at the D2, 5HT2D, and 5HT1D receptors, and as an agonist at the 5HT1A receptor. Â ... Similarly, it is reasonable to expect that the alpha-adrenergic-blocking properties of bretylium might be additive to those of ... Ziprasidones antagonism of α -adrenergic receptors may explain the orthostatic hypotension observed with this drug. ... No appreciable affinity was exhibited for other receptor/binding sites tested, including the cholinergic muscarinic receptor ( ...
The anti-nociceptive effect of MS-275 was blocked with an mGlu2/3 receptor antagonist [82]. Another group, Bai et al. [83], has ... Hocking LJ, Smith BH, Jones GT, Reid DM, Strachan DP, Macfarlane GJ: Genetic variation in the beta2-adrenergic receptor but not ... This approach was taken from the immunology field, where it was discovered that anti-tumor-necrosis factor alpha (TNFα) therapy ... encoding the beta-2 adrenergic receptor), which predicted both pain severity and duration after controlling for confounding ...
  • Another source names recurring urinary retention, recurring urinary infections, uncontrolled macrohematuria, bladder stones, hydronephrosis, combination with other α1-antagonists or dopamine agonists, and severe renal or hepatic impairment as contraindications. (wikipedia.org)
  • Yohimbine acts to block the lowering of cAMP by alpha-2 adrenoceptor agonists. (epigenetics-modulation-frontier.com)
  • Quantitative cell-based high-content screening for vasopressin receptor agonists using transfluor technology. (moleculardevices.co.jp)
  • CYX3 (an oral blend of T3, Yohimbine and Clenbuterol) Combines the synergistic fat burning power of beta adrenergic agonists) and alpha adrenergic antagonists (Yohimbine HCl), all to add the T3 characteristics of increase the metabolic rate by increasing Thyroid efficiency. (babystepsuae.com)
  • GABA (a) receptor agonists are like alcohol, barbiturates and benzodiazepine. (nursingstudy.org)
  • GABA(b) receptor agonists include propofol, sodium oxybate and Baclofen. (nursingstudy.org)
  • Clonidine and its sister, Guanfacine, are Adrenergic alpha-2 receptor selective agonists. (phoenixrising.me)
  • They are also I1 Imidazoline Receptor agonists. (phoenixrising.me)
  • Agonists of I1 Imidazoline receptors reduce blood pressure and helps reduce pain. (phoenixrising.me)
  • Pseudoephedrine is both an alpha-and beta-adrenergic receptor agonist. (arogga.com)
  • 20% of the time, it works like norepinephrine as an agonist on the other receptors. (phoenixrising.me)
  • It also directly stimulates beta-adrenergic receptors causing bronchial relaxation, increased heart rate and contractility. (arogga.com)
  • Comparison of effects of alpha receptor blockers on endothelial functions and coagulation parameters in patients with benign prostatic hyperplasia. (ac.ir)
  • Arylpiperazinyl) cyclohexyl sufonamides: Discovery of α1a/1d-selective adrenergic receptor antagonists for the treatment of Benign Prostatic Hyperplasia/Lower Urinary Tract Symptoms (BPH/LUTS). (ac.ir)
  • Since these medications bind nonspecifically to muscarinic, alpha, and histamine receptors all over the body, a patient's heart rate, blood pressure, sense of balance, and muscle control can be affected. (rdhmag.com)
  • There are five types of dopamine receptors with each having a specific function or functions. (nursingstudy.org)
  • through their binding to dopamine receptors, mainly the D2 receptor, they decrease the amount of dopamine released into the synaptic nerve gap. (rdhmag.com)
  • Atypical antipsychotic drugs block not only dopamine receptors, but also serotonin receptors, mainly the 5HT2A receptor. (rdhmag.com)
  • Triprolidine hydrochloride is a potent competitive histamine H1-receptor antagonist with antimuscarinic and mild sedative properties. (arogga.com)
  • Biological Activity: Yohimbine is a potent and relatively nonselective alpha 2-adrenergic receptor (AR) antagonist, with IC50 of 0.6 μM. (epigenetics-modulation-frontier.com)
  • Its main metabolite is silodosin glucuronide, which inhibits the α1A receptor with 1/8 of the affinity of the parent substance. (wikipedia.org)
  • Target: alpha 2-adrenergic receptor in vitro: Yohimbine inhibits alpha2-receptor antagonist with Ki of 1.05 nM, 1.19 nM, and 1.19 nM for α2A, α2B, α2C, respectively. (epigenetics-modulation-frontier.com)
  • Phentolamine, an alpha-adrenergic antagonist (1 microM), reduced sympathetic constriction in controls, but abolished this response in TiO2 exposed rats (max % change -22.3+/-3.1 control, -9.7+/-2.9 TiO2). (cdc.gov)
  • Epinephrine has been the drug of choice for the treatment of cardiac arrest, primarily for its alpha-adrenergic effects. (medscape.com)
  • Adrenergic receptors respond to both norepinephrine (noradreline) and epinephrine (adreneline). (phoenixrising.me)
  • Further studies are recommended to be conducted to investigate and compare the efficacy of carvedilol with that of other alpha-blockers with a larger sample size and over a longer period of time. (ac.ir)
  • clinical studies have shown good results with use of In group 1 , 6 patients were pregnanat women who alfa blockers and steroids (4). (gotomydoctor.com)
  • A family of proteins that bind to CELL SURFACE RECEPTORS and alter their specificity, signaling mechanism, or mode of intracellular transport. (lookformedical.com)
  • Cell surface receptors that bind peptide messengers with high affinity and regulate intracellular signals which influence the behavior of cells. (lookformedical.com)
  • Naloxone and naltrexone used in opioid antagonists drugs and as competitive antagonists bind to the opioid receptors without activating the receptors. (nursingstudy.org)
  • Both classes of antipsychotics bind nonspecifically to receptors in the body that are not their actual target. (rdhmag.com)
  • There are several biological mechanisms that maintain chronic pain at the cellular level [ 9 ] and that may serve as potential targets (Box 1). (biomedcentral.com)
  • By preventing reuptake of 5-HT presynaptically, SSRIs result in more 5-HT to stimulate postsynaptic 5-HT receptors. (msdmanuals.com)
  • It works by blocking receptors called alpha1A adrenoreceptors in the prostate gland, the bladder and the urethra (the tube that leads from the bladder to the outside of the body). (wikipedia.org)
  • Silodosin has high affinity for the α1A adrenergic receptor in the prostate, the bladder, and the prostatic urethra. (wikipedia.org)
  • [ 1 ] Neurogenic bladder is a term applied to urinary bladder malfunction due to neurologic dysfunction emanating from internal or external trauma, disease, or injury. (medscape.com)
  • When the bladder becomes full, the stretch receptors of the detrusor muscle send a signal to the pons, which in turn notifies the brain. (medscape.com)
  • Other common adverse effects (in more than 1% of patients) are dizziness, orthostatic hypotension, diarrhea, and clogged nose. (wikipedia.org)
  • These side effects are similar to those of other α1 antagonists. (wikipedia.org)
  • 3] in vivo: Yohimbine is an antagonist at alpha2-noradrenaline receptors with putative panicogenic effects in human subjects, was administered to Swiss-Webster mice at doses of 0.5, 1.0, and 2.0 mg/kg. (epigenetics-modulation-frontier.com)
  • They stimulate 5-HT 1 receptors, with antidepressant and anxiolytic effects, but they also stimulate 5-HT 2 receptors, commonly causing anxiety, insomnia, and sexual dysfunction, and 5-HT 3 receptors, commonly causing nausea and headache. (msdmanuals.com)
  • 5 Due to this nonspecificity of receptor binding, these drugs will produce many undesirable side effects that can make compliance an issue for patients. (rdhmag.com)
  • Evidence that UTP and ATP regulate phospholipase C through a common extracellular 5'-nucleotide receptor in human airway epithelial cells. (aspetjournals.org)
  • The Transfluor® Assay is a cell-based fluorescence assay used to screen for G-protein coupled receptor (GPCR) ligands and other potential drugs that regulate GPCRs by deactivating or desensitizing a common pathway. (moleculardevices.co.jp)
  • Schizophrenia is a severe neuropsychiatric disorder affecting about 1% of the world population. (jscimedcentral.com)
  • Recommended initiation of Paliperidone Mercury Pharma Prolonged Release suspension for injection is with a dose of 150 mg on treatment day 1 and 100 mg one week later (day 8), both administered in the deltoid muscle in order to attain therapeutic concentrations rapidly (see section 5.2). (medicines.org.uk)
  • Trazodone hydrochloride tablets are a selective serotonin reuptake inhibitor indicated for the treatment of major depressive disorder (MDD) ( 1 ). (nih.gov)
  • Alfa one adrenergic receptors are established treatment for lower ureteric stones by present on the smooth muscles of the ureter and so alfa facilitating its expulsion. (gotomydoctor.com)
  • [ 2 ] In addition, the 1-year survival rate associated with this condition has increased from only 20% (prior to 1950) to a survival rate of more than 90% with appropriate medical treatment. (medscape.com)
  • Treatment should be started with a low dose of Amiloride, i.e. 5mg (1 tablet), plus a low dosage of the other diuretic agent. (janusinfo.se)
  • 1 This means one in four of the people who present to your office could be taking a prescription medication for treatment of mental illness. (rdhmag.com)
  • de Reijke TM, Klarskov P. Comparative efficacy of two alpha-adrenoreceptor antagonists, doxazosin and alfuzosin, in patients with lower urinary tract symptoms from benign prostatic enlargement. (ac.ir)
  • This study was carried out to study the efficacy of tamsulosin ( alpha blocker) & deflazacort (steroid) in the management of lower ureteric stones. (gotomydoctor.com)
  • In addition, an isoform of the ISLET AMYLOID POLYPEPTIDE RECEPTOR is formed from this protein dimerizing with the CALCITONIN RECEPTOR. (lookformedical.com)
  • A receptor activity-modifying protein that is a subunit of specific G-PROTEIN COUPLED RECEPTORS. (lookformedical.com)
  • 1) Based on the data we have, this variant is out-competing others far faster than Beta and even Delta did 🚩🚩 https://t.co/R2Ac4e4N6s [Tweet]. (hypothes.is)
  • I hypothesize some people have a variant Alpha-2 receptor where Clonidine and norepinephrine do not fit fully well. (phoenixrising.me)
  • The I1 Imidazoline receptors in many functions including control of blood pressure, pain management, etc., though they usually don't include anxiety, alertness, wakefulness functions like the adrenergic receptors do. (phoenixrising.me)
  • Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. (lookformedical.com)
  • Modeling the cannabinoid receptor: a three-dimensional quantitative structure-activity analysis. (aspetjournals.org)
  • Distinct pathways of desensitization of A1- and A2-adenosine receptors in DDT1 MF-2 cells. (aspetjournals.org)
  • Since desensitization only occurs with an activated receptor, monitoring beta-arrestin translocation and subsequent receptor recycling provides a method to detect the activation of any GPCR. (moleculardevices.co.jp)
  • In contrast to current methods of screening GPCRs, the Transfluor technology is based on the mechanism for termination of GPCR signaling, known as receptor desensitization. (moleculardevices.co.jp)
  • Comparison of G-protein coupled receptor desensitization-related beta-arrestin redistribution using confocal and non-confocal imaging. (moleculardevices.co.jp)
  • Calcitonin receptors outside the nervous system mediate the role of calcitonin in calcium homeostasis. (lookformedical.com)
  • CGRP receptors are present in both the CENTRAL NERVOUS SYSTEM and the periphery. (lookformedical.com)
  • The pre-synaptic alpha-2 receptor is of interest since stimulating it reduces norepinephrine output from norepinephrine-releasing neurons of the norepinephrine system in the nervous system (which originates from the locus ceruleus and the lateral tegmental field). (phoenixrising.me)
  • Intra operative floppy iris syndrome occurs in some people taking alpha adrenoreceptor antagonists and may lead to complications during cataract surgery. (wikipedia.org)
  • [ 1 ] Cardiovascular end-organ damage may include myocardial ischemia/infarction, acute left ventricular dysfunction, acute pulmonary edema, and/or aortic dissection. (medscape.com)
  • It acts as an alpha-1 adrenergic receptor antagonist. (wikipedia.org)
  • Alpha-naphthoflavone acts as an antagonist of 2,3,7, 8-tetrachlorodibenzo-p-dioxin by forming an inactive complex with the Ah receptor. (aspetjournals.org)
  • Diagnosing PTSD in adults, adolescents, and children older than 6 years of age using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)[1] requires a certain type and level of traumatic event, a combination of required symptoms, and the absence of exclusionary criteria. (medscape.com)
  • Ergot alkaloid and alpha adrenergic receptor antagonist with vasoconstrictor effect which is less effective than ergotamine. (e-lactancia.org)
  • 5 There are two main classes of drugs in the antipsychotic family: conventional/typical and atypical (see Table 1). (rdhmag.com)
  • In addition, researchers can gain insight into the complexities of receptor degradation and recycling for a given target. (moleculardevices.co.jp)
  • Group 1 large number of patients (3). (gotomydoctor.com)
  • With the advent of antihypertensive agents, the incidence of hypertensive emergencies in the United States has declined from 7% to approximately 1% of patients with hypertension. (medscape.com)
  • Prostaglandin receptors in NIH 3T3 cells: coupling of one receptor to adenylate cyclase and of a second receptor to phospholipase C. (aspetjournals.org)
  • Biochemical analysis of solubilized angiotensin II receptors from murine neuroblastoma N1E-115 cells by covalent cross-linking and affinity purification. (aspetjournals.org)
  • Development and validation of algorithms for measuring G-protein coupled receptor activation in cells using the LSC-based imaging cytometer platform. (moleculardevices.co.jp)
  • SSRIs are selective to the 5-HT system but not specific for the different 5-HT receptors. (msdmanuals.com)
  • The role of calcitonin receptors in the brain is not well understood. (lookformedical.com)
  • High efficiency reconstitution of a phencyclidine/MK-801 receptor binding site solubilized from rat forebrain membranes. (aspetjournals.org)
  • Note that anytime the world 'selective' is used, this means that it also works on other receptors but prefers one versus the other. (phoenixrising.me)
  • Clonidine only works 80% of the time on alpha-2 receptors. (phoenixrising.me)
  • Molecular interaction of the human alpha 2-C10-adrenergic receptor, when expressed in Rat-1 fibroblasts, with multiple pertussis toxin-sensitive guanine nucleotide-binding proteins: studies with site-directed antisera. (aspetjournals.org)
  • This seems to be caused by silodosin's high selectivity for α1A receptors. (wikipedia.org)
  • Garippa RJ, Hoffman AF, Gradl G, Kirsch A. High-throughput confocal microscopy for beta-arrestin-green fluorescent protein translocation G protein-coupled receptor assays using the Evotec Opera. (moleculardevices.co.jp)
  • High-content screening of known G protein-coupled receptors by arrestin translocation. (moleculardevices.co.jp)
  • citation needed] Alpha-1 adrenergic receptor antagonists are being investigated as a means to male birth control due to their ability to inhibit ejaculation but not orgasm. (wikipedia.org)
  • The alpha 1C-adrenergic receptor: characterization of signal transduction pathways and mammalian tissue heterogeneity. (aspetjournals.org)
  • Nanoparticle inhalation modulates arteriolar sympathetic constriction: role of nitric oxide, prostanoids, and alpha-adrenergic receptors. (cdc.gov)
  • G-protein-coupled cell surface receptors for ADRENOMEDULLIN. (lookformedical.com)
  • The receptor then internalizes into endocytic vesicles prior to reprocessing and returns to the cell membrane. (moleculardevices.co.jp)
  • The average stone expulsion time for group 1,2&3 was 13.20,11.95&22.6 days respectively. (gotomydoctor.com)
  • Figure below] Assume 1 in 100 cases of Delta are admitted to hospital. (hypothes.is)
  • By attaching a fluorescent label to beta-arrestin, the location of the receptor-arrestin complex may be monitored during receptor activation. (moleculardevices.co.jp)