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.
A subclass of adenosine A2 receptors found in LEUKOCYTES, the SPLEEN, the THYMUS and a variety of other tissues. It is generally considered to be a receptor for ADENOSINE that couples to the GS, STIMULATORY G-PROTEIN.
A subtype of ADENOSINE RECEPTOR that is found expressed in a variety of tissues including the BRAIN and DORSAL HORN NEURONS. The receptor is generally considered to be coupled to the GI, INHIBITORY G-PROTEIN which causes down regulation of CYCLIC AMP.
Condition in which the plasma levels of homocysteine and related metabolites are elevated (>13.9 µmol/l). Hyperhomocysteinemia can be familial or acquired. Development of the acquired hyperhomocysteinemia is mostly associated with vitamins B and/or folate deficiency (e.g., PERNICIOUS ANEMIA, vitamin malabsorption). Familial hyperhomocysteinemia often results in a more severe elevation of total homocysteine and excretion into the urine, resulting in HOMOCYSTINURIA. Hyperhomocysteinemia is a risk factor for cardiovascular and neurodegenerative diseases, osteoporotic fractures and complications during pregnancy.
An enzyme that catalyzes the hydrolysis of ADENOSINE to INOSINE with the elimination of AMMONIA.
A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.
A subtype of ADENOSINE RECEPTOR that is found expressed in a variety of locations including the BRAIN and endocrine tissues. The receptor is generally considered to be coupled to the GI, INHIBITORY G-PROTEIN which causes down regulation of CYCLIC AMP.
A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia.
A subclass of adenosine A2 receptors found in the CECUM, the COLON, the BLADDER, and a variety of other tissues. It is generally considered to be a low affinity receptor for ADENOSINE that couples to the GS, STIMULATORY G-PROTEIN.
An enzyme that catalyzes the formation of ADP plus AMP from adenosine plus ATP. It can serve as a salvage mechanism for returning adenosine to nucleic acids. EC 2.7.1.20.
A subclass of ADENOSINE RECEPTORS that are generally considered to be coupled to the GS, STIMULATORY G-PROTEIN which causes up regulation of CYCLIC AMP.
Compounds that selectively bind to and activate ADENOSINE A2 RECEPTORS.
Compounds that selectively bind to and block the activation of ADENOSINE A2 RECEPTORS.
A class of cell surface receptors that prefer ADENOSINE to other endogenous PURINES. Purinergic P1 receptors are widespread in the body including the cardiovascular, respiratory, immune, and nervous systems. There are at least two pharmacologically distinguishable types (A1 and A2, or Ri and Ra).
Compounds that bind to and block the stimulation of ADENOSINE A1 RECEPTORS.
A multifunctional pyridoxal phosphate enzyme. In the second stage of cysteine biosynthesis it catalyzes the reaction of homocysteine with serine to form cystathionine with the elimination of water. Deficiency of this enzyme leads to HYPERHOMOCYSTEINEMIA and HOMOCYSTINURIA. EC 4.2.1.22.
A flavoprotein amine oxidoreductase that catalyzes the reversible conversion of 5-methyltetrahydrofolate to 5,10-methylenetetrahydrofolate. This enzyme was formerly classified as EC 1.1.1.171.
Compounds that bind to and stimulate ADENOSINE A1 RECEPTORS.
A sulfur-containing essential L-amino acid that is important in many body functions.
A group of water-soluble vitamins, some of which are COENZYMES.
Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS.
VITAMIN B 6 refers to several PICOLINES (especially PYRIDOXINE; PYRIDOXAL; & PYRIDOXAMINE) that are efficiently converted by the body to PYRIDOXAL PHOSPHATE which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, and aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into PYRIDOXAMINE phosphate. Although pyridoxine and Vitamin B 6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading (EE Snell; Ann NY Acad Sci, vol 585 pg 1, 1990). Most of vitamin B6 is eventually degraded to PYRIDOXIC ACID and excreted in the urine.
Purine bases found in body tissues and fluids and in some plants.
Compounds that bind to and stimulate PURINERGIC P1 RECEPTORS.
A ZINC metalloenzyme that catalyzes the transfer of a methyl group from BETAINE to HOMOCYSTEINE to produce dimethylglycine and METHIONINE, respectively. This enzyme is a member of a family of ZINC-dependent METHYLTRANSFERASES that use THIOLS or selenols as methyl acceptors.
Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position.
5'-S-(3-Amino-3-carboxypropyl)-5'-thioadenosine. Formed from S-adenosylmethionine after transmethylation reactions.
An enzyme that catalyzes the formation of methionine by transfer of a methyl group from 5-methyltetrahydrofolate to homocysteine. It requires a cobamide coenzyme. The enzyme can act on mono- or triglutamate derivatives. EC 2.1.1.13.
A stable adenosine A1 and A2 receptor agonist. Experimentally, it inhibits cAMP and cGMP phosphodiesterase activity.
Autosomal recessive inborn error of methionine metabolism usually caused by a deficiency of CYSTATHIONINE BETA-SYNTHASE and associated with elevations of homocysteine in plasma and urine. Clinical features include a tall slender habitus, SCOLIOSIS, arachnodactyly, MUSCLE WEAKNESS, genu varus, thin blond hair, malar flush, lens dislocations, an increased incidence of MENTAL RETARDATION, and a tendency to develop fibrosis of arteries, frequently complicated by CEREBROVASCULAR ACCIDENTS and MYOCARDIAL INFARCTION. (From Adams et al., Principles of Neurology, 6th ed, p979)
Enzymes catalyzing the dehydrogenation of secondary amines, introducing a C=N double bond as the primary reaction. In some cases this is later hydrolyzed.
A methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac and central nervous system stimulant activities. Theophylline inhibits the 3',5'-CYCLIC NUCLEOTIDE PHOSPHODIESTERASE that degrades CYCLIC AMP thus potentiates the actions of agents that act through ADENYLYL CYCLASES and cyclic AMP.
A nutritional condition produced by a deficiency of VITAMIN B 12 in the diet, characterized by megaloblastic anemia. Since vitamin B 12 is not present in plants, humans have obtained their supply from animal products, from multivitamin supplements in the form of pills, and as additives to food preparations. A wide variety of neuropsychiatric abnormalities is also seen in vitamin B 12 deficiency and appears to be due to an undefined defect involving myelin synthesis. (From Cecil Textbook of Medicine, 19th ed, p848)
Compounds that selectively bind to and block the activation of ADENOSINE A3 RECEPTORS.
A nutritional condition produced by a deficiency of FOLIC ACID in the diet. Many plant and animal tissues contain folic acid, abundant in green leafy vegetables, yeast, liver, and mushrooms but destroyed by long-term cooking. Alcohol interferes with its intermediate metabolism and absorption. Folic acid deficiency may develop in long-term anticonvulsant therapy or with use of oral contraceptives. This deficiency causes anemia, macrocytic anemia, and megaloblastic anemia. It is indistinguishable from vitamin B 12 deficiency in peripheral blood and bone marrow findings, but the neurologic lesions seen in B 12 deficiency do not occur. (Merck Manual, 16th ed)
Cell surface proteins that bind PURINES with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized classes of purinergic receptors in mammals are the P1 receptors, which prefer ADENOSINE, and the P2 receptors, which prefer ATP or ADP.
An antibiotic purine ribonucleoside that readily substitutes for adenosine in the biological system, but its incorporation into DNA and RNA has an inhibitory effect on the metabolism of these nucleic acids.
Drugs that selectively bind to and activate ADENOSINE A3 RECEPTORS.
Physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in treatment of chronic liver disease. (From Merck, 11th ed)
A purine nucleoside that has hypoxanthine linked by the N9 nitrogen to the C1 carbon of ribose. It is an intermediate in the degradation of purines and purine nucleosides to uric acid and in pathways of purine salvage. It also occurs in the anticodon of certain transfer RNA molecules. (Dorland, 28th ed)
2-Chloroadenosine. A metabolically stable analog of adenosine which acts as an adenosine receptor agonist. The compound has a potent effect on the peripheral and central nervous system.
A malonic acid derivative which is a vital intermediate in the metabolism of fat and protein. Abnormalities in methylmalonic acid metabolism lead to methylmalonic aciduria. This metabolic disease is attributed to a block in the enzymatic conversion of methylmalonyl CoA to succinyl CoA.
A group of compounds that are derivatives of beta- aminoethylbenzene which is structurally and pharmacologically related to amphetamine. (From Merck Index, 11th ed)
N-Isopropyl-N-phenyl-adenosine. Antilipemic agent. Synonym: TH 162.
A naturally occurring compound that has been of interest for its role in osmoregulation. As a drug, betaine hydrochloride has been used as a source of hydrochloric acid in the treatment of hypochlorhydria. Betaine has also been used in the treatment of liver disorders, for hyperkalemia, for homocystinuria, and for gastrointestinal disturbances. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1341)
A glycoprotein enzyme present in various organs and in many cells. The enzyme catalyzes the hydrolysis of a 5'-ribonucleotide to a ribonucleoside and orthophosphate in the presence of water. It is cation-dependent and exists in a membrane-bound and soluble form. EC 3.1.3.5.
An enzyme which catalyzes the catabolism of S-ADENOSYLHOMOCYSTEINE to ADENOSINE and HOMOCYSTEINE. It may play a role in regulating the concentration of intracellular adenosylhomocysteine.
An enzyme that catalyzes the demethylation of L-homocysteine to L-METHIONINE.
The 4-methanol form of VITAMIN B 6 which is converted to PYRIDOXAL PHOSPHATE which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. Although pyridoxine and Vitamin B 6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading (EE Snell; Ann NY Acad Sci, vol 585 pg 1, 1990).
An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
An FAD-dependent oxidoreductase found primarily in BACTERIA. It is specific for the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. This enzyme was formerly listed as EC 1.1.1.68 and 1.1.99.15.
An enzyme that catalyzes the METHYLATION of GLYCINE using S-ADENOSYLMETHIONINE to form SARCOSINE with the concomitant production of S-ADENOSYLHOMOCYSTEINE.
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.
Compounds based on 5,6,7,8-tetrahydrofolate.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Products in capsule, tablet or liquid form that provide dietary ingredients, and that are intended to be taken by mouth to increase the intake of nutrients. Dietary supplements can include macronutrients, such as proteins, carbohydrates, and fats; and/or MICRONUTRIENTS, such as VITAMINS; MINERALS; and PHYTOCHEMICALS.
An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.
Catalyze the hydrolysis of nucleosides with the elimination of ammonia.
A ribonucleoside antibiotic synergist and adenosine deaminase inhibitor isolated from Nocardia interforma and Streptomyces kaniharaensis. It is proposed as an antineoplastic synergist and immunosuppressant.
A condition due to deficiency in any member of the VITAMIN B COMPLEX. These B vitamins are water-soluble and must be obtained from the diet because they are easily lost in the urine. Unlike the lipid-soluble vitamins, they cannot be stored in the body fat.
A phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. Dipyridamole also potentiates the antiaggregating action of prostacyclin. (From AMA Drug Evaluations Annual, 1994, p752)
A group of carrier proteins which bind with VITAMIN B12 in the BLOOD and aid in its transport. Transcobalamin I migrates electrophoretically as a beta-globulin, while transcobalamins II and III migrate as alpha-globulins.
Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)
3,7-Dimethylxanthine. The principle alkaloid in Theobroma cacao (the cacao bean) and other plants. A xanthine alkaloid that is used as a bronchodilator and as a vasodilator. It has a weaker diuretic activity than THEOPHYLLINE and is also a less powerful stimulant of smooth muscle. It has practically no stimulant effect on the central nervous system. It was formerly used as a diuretic and in the treatment of angina pectoris and hypertension. (From Martindale, The Extra Pharmacopoeia, 30th ed, pp1318-9)
The rate dynamics in chemical or physical systems.
A nutritional condition produced by a deficiency of VITAMIN B 6 in the diet, characterized by dermatitis, glossitis, cheilosis, and stomatitis. Marked deficiency causes irritability, weakness, depression, dizziness, peripheral neuropathy, and seizures. In infants and children typical manifestations are diarrhea, anemia, and seizures. Deficiency can be caused by certain medications, such as isoniazid.
This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).
A potent inhibitor of ADENOSINE DEAMINASE. The drug induces APOPTOSIS of LYMPHOCYTES, and is used in the treatment of many lymphoproliferative malignancies, particularly HAIRY CELL LEUKEMIA. It is also synergistic with some other antineoplastic agents and has immunosuppressive activity.
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.
A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.
5'-Adenylic acid, monoanhydride with sulfuric acid. The initial compound formed by the action of ATP sulfurylase on sulfate ions after sulfate uptake. Synonyms: adenosine sulfatophosphate; APS.
An amino acid intermediate in the metabolism of choline.
A purine base and a fundamental unit of ADENINE NUCLEOTIDES.
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
Adenosine molecules which can be substituted in any position, but are lacking one hydroxyl group in the ribose part of the molecule.
A multifunctional pyridoxal phosphate enzyme. In the final step in the biosynthesis of cysteine it catalyzes the cleavage of cystathionine to yield cysteine, ammonia, and 2-ketobutyrate. EC 4.4.1.1.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.
Drugs used to cause dilation of the blood vessels.
Elements of limited time intervals, contributing to particular results or situations.
Sulfhydryl analog of INOSINE that inhibits nucleoside transport across erythrocyte plasma membranes, and has immunosuppressive properties. It has been used similarly to MERCAPTOPURINE in the treatment of leukemia. (From Martindale, The Extra Pharmacopoeia, 30th ed, p503)
Heterocyclic rings containing three nitrogen atoms, commonly in 1,2,4 or 1,3,5 or 2,4,6 formats. Some are used as HERBICIDES.
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.
Pathological conditions involving the CARDIOVASCULAR SYSTEM including the HEART; the BLOOD VESSELS; or the PERICARDIUM.
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
Endogenous factors or drugs that increase the transport and metabolism of LIPIDS including the synthesis of LIPOPROTEINS by the LIVER and their uptake by extrahepatic tissues.
Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.
Pathological processes involving any of the BLOOD VESSELS in the cardiac or peripheral circulation. They include diseases of ARTERIES; VEINS; and rest of the vasculature system in the body.
A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
A subclass of enzymes of the transferase class that catalyze the transfer of a methyl group from one compound to another. (Dorland, 28th ed) EC 2.1.1.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Drugs that bind to and block the activation of PURINERGIC RECEPTORS.
Compounds containing the -SH radical.
Abstaining from all food.
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
Regular course of eating and drinking adopted by a person or animal.
Beta-Sulfoalanine. An amino acid with a C-terminal sulfonic acid group which has been isolated from human hair oxidized with permanganate. It occurs normally in the outer part of the sheep's fleece, where the wool is exposed to light and weather.
A drug combination that contains THEOPHYLLINE and ethylenediamine. It is more soluble in water than theophylline but has similar pharmacologic actions. It's most common use is in bronchial asthma, but it has been investigated for several other applications.
The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.
A calcium-activated enzyme that catalyzes the hydrolysis of ATP to yield AMP and orthophosphate. It can also act on ADP and other nucleoside triphosphates and diphosphates. EC 3.6.1.5.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
An enzyme that catalyses three sequential METHYLATION reactions for conversion of phosphatidylethanolamine to PHOSPHATIDYLCHOLINE.
Fluoroimmunoassay where detection of the hapten-antibody reaction is based on measurement of the increased polarization of fluorescence-labeled hapten when it is combined with antibody. The assay is very useful for the measurement of small haptenic antigens such as drugs at low concentrations.
A basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism.
Proteins involved in the transport of NUCLEOSIDES across cellular membranes.
A class of enzymes that catalyze the conversion of a nucleotide and water to a nucleoside and orthophosphate. EC 3.1.3.-.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.
An enzyme that catalyzes the oxidation and reduction of FERREDOXIN or ADRENODOXIN in the presence of NADP. EC 1.18.1.2 was formerly listed as EC 1.6.7.1 and EC 1.6.99.4.
Congenital malformations of the central nervous system and adjacent structures related to defective neural tube closure during the first trimester of pregnancy generally occurring between days 18-29 of gestation. Ectodermal and mesodermal malformations (mainly involving the skull and vertebrae) may occur as a result of defects of neural tube closure. (From Joynt, Clinical Neurology, 1992, Ch55, pp31-41)
Purine or pyrimidine bases attached to a ribose or deoxyribose. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as FLAVIN MONONUCLEOTIDE and FLAVIN-ADENINE DINUCLEOTIDE.
Organic substances that are required in small amounts for maintenance and growth, but which cannot be manufactured by the human body.
State of the body in relation to the consumption and utilization of nutrients.
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.
Any food that has been supplemented with essential nutrients either in quantities that are greater than those present normally, or which are not present in the food normally. Fortified food includes also food to which various nutrients have been added to compensate for those removed by refinement or processing. (From Segen, Dictionary of Modern Medicine, 1992)
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.
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
Peptides composed of two amino acid units.
The circulation of blood through the CORONARY VESSELS of the HEART.
Thickening and loss of elasticity of the walls of ARTERIES of all sizes. There are many forms classified by the types of lesions and arteries involved, such as ATHEROSCLEROSIS with fatty lesions in the ARTERIAL INTIMA of medium and large muscular arteries.
An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.
An enzyme that activates methionine with its specific transfer RNA. EC 6.1.1.10.
An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.
A cyclic nucleotide derivative that mimics the action of endogenous CYCLIC AMP and is capable of permeating the cell membrane. It has vasodilator properties and is used as a cardiac stimulant. (From Merck Index, 11th ed)
Agents which improve the quality of the blood, increasing the hemoglobin level and the number of erythrocytes. They are used in the treatment of anemias.
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.
Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.
Nucleosides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Any member of the class of enzymes that catalyze the cleavage of the substrate and the addition of water to the resulting molecules, e.g., ESTERASES, glycosidases (GLYCOSIDE HYDROLASES), lipases, NUCLEOTIDASES, peptidases (PEPTIDE HYDROLASES), and phosphatases (PHOSPHORIC MONOESTER HYDROLASES). EC 3.
A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.
A class of cell surface receptors for PURINES that prefer ATP or ADP over ADENOSINE. P2 purinergic receptors are widespread in the periphery and in the central and peripheral nervous system.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).
Established cell cultures that have the potential to propagate indefinitely.
A sulfate salt of copper. It is a potent emetic and is used as an antidote for poisoning by phosphorus. It also can be used to prevent the growth of algae.
An individual in which both alleles at a given locus are identical.
This enzyme catalyzes the last step of CREATINE biosynthesis by catalyzing the METHYLATION of guanidinoacetate to CREATINE.
The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
An NADP-dependent oxidoreductase that catalyses the conversion of 5,10-methyleneterahydrofolate to 5,10-methenyl-tetrahydrofolate. In higher eukaryotes a trifunctional enzyme exists with additional METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE and FORMATE-TETRAHYDROFOLATE LIGASE activity. The enzyme plays an important role in the synthesis of 5-methyltetrahydrofolate, the methyl donor for the VITAMIN B12-dependent remethylation of HOMOCYSTEINE to METHIONINE via METHIONINE SYNTHETASE.
PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
A beverage made from ground COFFEA beans (SEEDS) infused in hot water. It generally contains CAFFEINE and THEOPHYLLINE unless it is decaffeinated.
An enzyme that catalyzes the synthesis of S-adenosylmethionine from methionine and ATP. EC 2.5.1.6.
A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
A long-acting derivative of cyclic AMP. It is an activator of cyclic AMP-dependent protein kinase, but resistant to degradation by cyclic AMP phosphodiesterase.
Potent activator of the adenylate cyclase system and the biosynthesis of cyclic AMP. From the plant COLEUS FORSKOHLII. Has antihypertensive, positive inotropic, platelet aggregation inhibitory, and smooth muscle relaxant activities; also lowers intraocular pressure and promotes release of hormones from the pituitary gland.
Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.
Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.
An enzyme found primarily in the LIVER that catalyzes the N-methylation of NICOTINAMIDE and other structurally related compounds.
A lipoprotein that resembles the LOW-DENSITY LIPOPROTEINS but with an extra protein moiety, APOPROTEIN (A) also known as APOLIPOPROTEIN (A), linked to APOLIPOPROTEIN B-100 on the LDL by one or two disulfide bonds. High plasma level of lipoprotein (a) is associated with increased risk of atherosclerotic cardiovascular disease.
The presence of an increased amount of blood in a body part or an organ leading to congestion or engorgement of blood vessels. Hyperemia can be due to increase of blood flow into the area (active or arterial), or due to obstruction of outflow of blood from the area (passive or venous).
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
A potent cyclic nucleotide phosphodiesterase inhibitor; due to this action, the compound increases cyclic AMP and cyclic GMP in tissue and thereby activates CYCLIC NUCLEOTIDE-REGULATED PROTEIN KINASES
Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.
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.
A plasma protein that circulates in increased amounts during inflammation and after tissue damage.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
The hollow, muscular organ that maintains the circulation of the blood.
A condition produced by a deficiency of CHOLINE in animals. Choline is known as a lipotropic agent because it has been shown to promote the transport of excess fat from the liver under certain conditions in laboratory animals. Combined deficiency of choline (included in the B vitamin complex) and all other methyl group donors causes liver cirrhosis in some animals. Unlike compounds normally considered as vitamins, choline does not serve as a cofactor in enzymatic reactions. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)
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.
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Treatment process involving the injection of fluid into an organ or tissue.
A class of enzymes that catalyze the cleavage of C-C, C-O, and C-N, and other bonds by other means than by hydrolysis or oxidation. (Enzyme Nomenclature, 1992) EC 4.
Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.
The end-stage of CHRONIC RENAL INSUFFICIENCY. It is characterized by the severe irreversible kidney damage (as measured by the level of PROTEINURIA) and the reduction in GLOMERULAR FILTRATION RATE to less than 15 ml per min (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002). These patients generally require HEMODIALYSIS or KIDNEY TRANSPLANTATION.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Nucleosides in which the base moiety is substituted with one or more sulfur atoms.
Purines with a RIBOSE attached that can be phosphorylated to PURINE NUCLEOTIDES.
Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)
Formation and development of a thrombus or blood clot in the blood vessel.
The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.
Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).
A group of compounds which consist of a nucleotide molecule to which an additional nucleoside is attached through the phosphate molecule(s). The nucleotide can contain any number of phosphates.
Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
A process that changes the nucleotide sequence of mRNA from that of the DNA template encoding it. Some major classes of RNA editing are as follows: 1, the conversion of cytosine to uracil in mRNA; 2, the addition of variable number of guanines at pre-determined sites; and 3, the addition and deletion of uracils, templated by guide-RNAs (RNA, GUIDE).
A subtype of equilibrative nucleoside transporter proteins that is sensitive to inhibition by 4-nitrobenzylthioinosine.
De La Haba G, Cantoni GL (March 1959). "The enzymatic synthesis of S-adenosyl-L-homocysteine from adenosine and homocysteine". ... This enzyme catalyses the following chemical reaction S-adenosyl-L-homocysteine + H2O ⇌ L-homocysteine + adenosine The enzyme ... is an enzyme that converts S-adenosylhomocysteine to homocysteine and adenosine. ...
In theory, it would increase S-adenosylmethionine (SAMe) by remethylating homocysteine. The same homocysteine-to-methionine ... behave with thermodynamics similar to those of thymidine and adenosine (weak binders). It has been determined under experiment ... TMG supplementation lowers homocysteine but also raises LDL-cholesterol in obese individuals and renal patients. ... Olthof MR, van Vliet T, Verhoef P, Zock PL, Katan MB (2005). "Effect of homocysteine-lowering nutrients on blood lipids: ...
... an enzyme that catalyzes the chemical reaction adenosine 3',5'-bisphosphate + H2O adenosine 5'-phosphate + phosphate Fructose 1 ... lysine S-adenosyl-L-homocysteine + [ribulose-1,5-bisphosphate carboxylase]-N6-methyl-L-lysine 3'(2'),5'-bisphosphate ...
This is hydrolysed to homocysteine and adenosine by S-adenosylhomocysteine hydrolase EC 3.3.1.1 and the homocysteine recycled ... that use SAM-e as a substrate produce S-adenosyl homocysteine as a product. S-Adenosyl homocysteine is a strong negative ... It is made from adenosine triphosphate (ATP) and methionine by methionine adenosyltransferase. SAM-e was first discovered by ... Finkelstein J, Martin J (2000). "Homocysteine". Int J Biochem Cell Biol. 32 (4): 385-9. doi:10.1016/S1357-2725(99)00138-7. PMID ...
S-adenosyl-L-homocysteine + L-methionine + 5'-deoxyadenosine + 2-methyladenine2503 in 23S rRNA 23S rRNA (adenine2503-C2)- ... "The methyltransferase YfgB/RlmN is responsible for modification of adenosine 2503 in 23S rRNA". RNA. 14 (1): 98-106. doi: ...
... adenosine, and S-adenosyl-L-homocysteine in the mothers of these children. Her glutathione-related research has been cited by ... found that autistic children exhibit abnormal folate metabolism that is detectable by higher levels of plasma homocysteine, ...
... from S-adenosine-L-methionine and chloride. This protein has been purified and expressed in E. coli, and seems to be present in ... S-adenosyl-L-homocysteine + methyl iodide This enzyme contributes to the methyl halide emissions from Arabidopsis thaliana. The ...
The adenosine is then hydrolyzed to yield L-homocysteine. L-Homocysteine has two primary fates: conversion via tetrahydrofolate ... Homocysteine MS Spectrum Homocysteine at Lab Tests Online Homocysteine: analyte monograph[permanent dead link] - The ... Homocysteine is biosynthesized naturally via a multi-step process. First, methionine receives an adenosine group from ATP, a ... Homocysteine also acts as an allosteric antagonist at Dopamine D2 receptors. It has been proposed that both homocysteine and ...
... which is cleaved by SAH hydrolase into Ado and homocysteine. The failure to efficiently remove these end products (Ado removed ... Adenosine kinase (AdK; EC 2.7.1.20) is an enzyme that catalyzes the transfer of gamma-phosphate from Adenosine triphosphate ( ... Gupta RS (June 1996). "Adenosine-AMP exchange activity is an integral part of the mammalian adenosine kinase". Biochemistry and ... Arch JR, Newsholme EA (September 1978). "Activities and some properties of 5'-nucleotidase, adenosine kinase and adenosine ...
Adenosylhomocysteinase converts SAH into homocysteine and adenosine. Finkelstein, J. D. (2000). "Pathways and regulation of ... S-Adenosyl-l-homocysteine (SAH) is the biosynthetic precursor to homocysteine. SAH is formed by the demethylation of S-adenosyl ... BioCYC E.Coli K-12 Compound: S-adenosyl-L-homocysteine v t e. ... homocysteine metabolism in mammals". Semin. Thromb. Hemost. 26 ... Potential Epigenetic Mechanism for Homocysteine-Related Pathology". The Journal of Nutrition. 132 (8): 2361S-2366S. doi:10.1093 ...
... responsible for the reversible hydration of S-adenosyl-L-homocysteine into adenosine and homocysteine. AdoHcyase is a ... S-adenosyl-L-homocysteine hydrolase (EC 3.3.1.1) (AdoHcyase) is an enzyme of the activated methyl cycle, ... Sganga MW, Aksamit RR, Cantoni GL, Bauer CE (1992). "Mutational and nucleotide sequence analysis of S-adenosyl-L-homocysteine ... AdoHcyase is significantly associated with adenosine deaminase deficiency, which classically manifests in severe combine ...
O-ribose methyl-adenosine (i.e. 5′(m7Gp)(ppAm)[pN]n), it can be further methylated at the N6 methyl position to form N6- ... with S-adenosyl-L-methionine being demethylated to produce S-adenosyl-L-homocysteine, resulting in 5′(m7Gp)(ppN)[pN]n (cap-0); ...
UH-232 Homocysteine - negative allosteric modulator PAOPA SB-269,652 SB-269,652 1-(6-(((R,S)-7-Hydroxychroman-2-yl)methylamino] ... D1-D2 dopamine receptor heteromer D2-adenosine A2A D2-ghrelin receptor D2sh-TAAR1 The D2 receptor has been shown to form ... "Allosteric modulation of dopamine D2 receptors by homocysteine". Journal of Proteome Research. 5 (11): 3077-83. CiteSeerX 10.1. ...
This differs from the process in yeast, where sulfide must be incorporated first in homocysteine then converted in two steps to ... Sulfate needs to be activated to adenosine 5'-phosphosulfate (APS) prior to its reduction to sulfite. The activation of sulfate ... This happens through the transsulfuration pathway and the methylation of homocysteine. Both cysteine and methionine are sulfur- ...
Gefter ML (1969). "The in vitro synthesis of 2'-omethylguanosine and 2-methylthio 6N (gamma,gamma, dimethylallyl) adenosine in ... S-adenosyl-L-homocysteine + tRNA containing 2'-O-methylguanosine Thus, the two substrates of this enzyme are S-adenosyl ...
Adenosine monophosphate (AMP) Adenosine triphosphate (ATP) Adenylate cyclase Adiponectin Adonitol Adrenaline, epinephrine ... HDL Histamine Histidine Histone Histone methyltransferase HLA antigen Homocysteine Hormone human chorionic gonadotropin (hCG) ... Abamectine Abietic acid Acetic acid Acetylcholine Actin Actinomycin D Adenine Adenosmeme Adenosine diphosphate (ADP) ... Cortisol Creatine Creatine kinase Crystallin Cyclic adenosine monophosphate (cAMP) α-Cyclodextrin Cyclodextrin ...
Category:EC 3.3 Adenosylmethionine hydrolase S-adenosyl-L-homocysteine hydrolase Alkenylglycerophosphocholine hydrolase ... Adenosine deaminase (EC 3.5.4.4) GTP cyclohydrolase I (EC 3.5.4.16) Category:EC 3.5.5 (In nitriles) Nitrilase (EC 3.5.5.1) ... adenosine-forming) Category:EC 4.1.1 Ornithine decarboxylase (EC 4.1.1.17) Uridine monophosphate synthetase (EC 4.1.1.23) ...
... cyclic adenosine monophosphate-dependent gene expression". Molecular Endocrinology. 8 (1): 59-68. doi:10.1210/mend.8.1.8152431 ... repressor ATF3/LRF1 through the IRE1/TRAF2 pathway is implicated in human vascular endothelial cell death by homocysteine". ... cyclic adenosine monophosphate-dependent gene expression". Molecular Endocrinology. 8 (1): 59-68. doi:10.1210/mend.8.1.8152431 ...
Caffeine is usually held 24 hours prior to an adenosine stress test, as it is a competitive antagonist of the A2A adenosine ... Examples of physiological methods Lipoprotein analysis HbA1c Hs-CRP Homocysteine The anatomic methods directly measure some ... Commonly used agents include: Vasodilators acting as adenosine receptor agonists, such as adenosine itself, and dipyridamole ( ... Adenosine and dipyridamole can cause mild hypotension. As the tracers used for this test are carcinogenic, frequent use of ...
EC 2.1.1.1: nicotinamide N-methyltransferase EC 2.1.1.2: guanidinoacetate N-methyltransferase EC 2.1.1.3: thetin-homocysteine S ... adenosine kinase EC 2.7.1.21: thymidine kinase EC 2.7.1.22: ribosylnicotinamide kinase EC 2.7.1.23: NAD+ kinase EC 2.7.1.24: ... adenosine-2'-O-)-methyltransferase EC 2.1.1.67: thiopurine S-methyltransferase EC 2.1.1.68: caffeate O-methyltransferase EC 2.1 ... homocysteine S-methyltransferase EC 2.1.1.11: magnesium protoporphyrin IX methyltransferase EC 2.1.1.12: methionine S- ...
... homocysteine S-methyltransferase MeSH D08.811.913.555.500.645 - 5-methyltetrahydrofolate-homocysteine s-methyltransferase MeSH ... adenosine kinase MeSH D08.811.913.696.620.155 - choline kinase MeSH D08.811.913.696.620.175 - deoxycytidine kinase MeSH D08.811 ... adenosine deaminase MeSH D08.811.277.151.486.250 - cytidine deaminase MeSH D08.811.277.151.486.625 - cytosine deaminase MeSH ... betaine-homocysteine S-methyltransferase MeSH D08.811.913.555.500.250 - catechol O-methyltransferase MeSH D08.811.913.555. ...
SAM is converted to S-Adenosyl homocysteine (SAH) during this process. The breaking of the SAM-methyl bond and the formation of ... RlmN is ubiquitous in bacteria which enhances translational fidelity and RlmN catalyzes methylation of C2 of adenosine 2503 ( ... A2503) in 23 S rRNA and C2 of adenosine (A37). Cfr, on the other hand, catalyzes methylation of C8 of A2503 as well and it also ... DNA adenine S-adenosyl-L-homocysteine + DNA 6-methylaminopurine m6A was primarily found in prokaryotes until 2015 when it was ...
Neurons that produce GABA as their output are called GABAergic neurons, and have chiefly inhibitory action at receptors in the adult vertebrate. Medium spiny cells are a typical example of inhibitory central nervous system GABAergic cells. In contrast, GABA exhibits both excitatory and inhibitory actions in insects, mediating muscle activation at synapses between nerves and muscle cells, and also the stimulation of certain glands.[4] In mammals, some GABAergic neurons, such as chandelier cells, are also able to excite their glutamatergic counterparts.[5] GABAA receptors are ligand-activated chloride channels: when activated by GABA, they allow the flow of chloride ions across the membrane of the cell. Whether this chloride flow is depolarizing (makes the voltage across the cell's membrane less negative), shunting (has no effect on the cell's membrane potential), or inhibitory/hyperpolarizing (makes the cell's membrane more negative) depends on the direction of the flow of chloride. When net ...
Long-term use of metformin has been associated with increased homocysteine levels and malabsorption of vitamin B12. Higher ... 2018). "HL156A, a novel pharmacological agent with potent adenosine-monophosphate-activated protein kinase (AMPK) activator ... November 2003). "Effects of short-term treatment with metformin on serum concentrations of homocysteine, folate and vitamin B12 ... as opposed to a change in total AMP or total AMP/adenosine triphosphate). Increased cellular AMP has been proposed to explain ...
The methylation of adenosine is directed by a large m6A methyltransferase complex containing METTL3 as the SAM-binding sub-unit ... "Genetic profile and determinants of homocysteine levels in Kazakhstan patients with breast cancer". Anticancer Research. 33 (9 ... Zhong S, Li H, Bodi Z, Button J, Vespa L, Herzog M, Fray RG (May 2008). "MTA is an Arabidopsis messenger RNA adenosine ... Bodi Z, Zhong S, Mehra S, Song J, Graham N, Li H, May S, Fray RG (2012). "Adenosine Methylation in Arabidopsis mRNA is ...
generation of homocysteine: S-Adenosyl methionine. *S-Adenosyl-L-homocysteine. *Homocysteine. *conversion to cysteine: ... Adenosine monophosphate. *Kainic acid. *Monosodium glutamate. References[edit]. *^ "L-Glutamic acid CAS#: 56-86-0". www. ...
Besides the nervous system, GABA is also produced at relatively high levels in the insulin-producing β-cells of the pancreas. The β-cells secrete GABA along with insulin and the GABA binds to GABA receptors on the neighboring islet α-cells and inhibits them from secreting glucagon (which would counteract insulin's effects).[25] GABA can promote the replication and survival of β-cells[26][27][28] and also promote the conversion of α-cells to β-cells, which may lead to new treatments for diabetes.[29] GABA has also been detected in other peripheral tissues including intestines, stomach, Fallopian tubes, uterus, ovaries, testes, kidneys, urinary bladder, the lungs and liver, albeit at much lower levels than in neurons or β-cells. GABAergic mechanisms have been demonstrated in various peripheral tissues and organs, which include the intestines, the stomach, the pancreas, the Fallopian tubes, the uterus, the ovaries, the testes, the kidneys, the urinary bladder, the lungs, and the liver.[30] ...
Hohman, R.J.; Guitton, M.C.; Véron, M. (1984). "Purification of S-adenosyl-l-homocysteine hydrolase from Dictyostelium ... Dhawan, S; Hensley, P; Osborne Jr, JC; Fleming, PJ (1986). "Adenosine 5'-diphosphate-dependent subunit dissociation of bovine ... Kajander, EO; Raina, AM (1981). "Affinity-chromatographic purification of S-adenosyl-L-homocysteine hydrolase. Some properties ... Activation by monovalent cations and an analysis of the effect of the adenosine triphosphate-magnesium ion complex on this ...
In his book, Dawkins cites experiments performed by Julius Rebek and his colleagues in which they combined amino adenosine and ... It has also been proposed that cysteine and homocysteine may have reacted with nitriles resulting from the Stecker reaction, ... They are also logical precursors in the synthesis of such key biochemical compounds as adenosine triphosphate (ATP). A key ... pentafluorophenyl esters with the autocatalyst amino adenosine triacid ester (AATE). One product was a variant of AATE, which ...
Vitamin B8: adenosine monophosphate (AMP), also known as adenylic acid.[43] Vitamin B8 may also refer to inositol.[44] ... Deficiency results in a macrocytic anemia, and elevated levels of homocysteine. Deficiency in pregnant women can lead to birth ... Deficiency results in a macrocytic anemia, elevated methylmalonic acid and homocysteine, peripheral neuropathy, memory loss and ...
... is derived from cysteine (and homocysteine). In mammals, the biosynthesis of hypotaurine from cysteine occurs in ...
Fumarate is an intermediate in the citric acid cycle used by cells to produce energy in the form of adenosine triphosphate (ATP ... generation of homocysteine: S-Adenosyl methionine. *S-Adenosyl-L-homocysteine. *Homocysteine. *conversion to cysteine: ...
Défhosfáit adanóisín Adenosine diphosphate (ADP). *Aonfhosfáit adanóisín Adenosine monophosphate (AMP). *Trífhosfáit adanóisín ...
... and adenosine monophosphate (AMP).[5][8][26] Other inhibitors/regulators are glycine and alanine. Alanine, glycine, and serine ... regeneration of methionine: Methionine synthase/Homocysteine methyltransferase. *Betaine-homocysteine methyltransferase. * ...
generation of homocysteine: S-Adenosyl methionine. *S-Adenosyl-L-homocysteine. *Homocysteine. *conversion to cysteine: ...
The first reaction of histidine biosynthesis is the condensation of PRPP and adenosine triphosphate (ATP) by the enzyme ATP- ... generation of homocysteine: S-Adenosyl methionine. *S-Adenosyl-L-homocysteine. *Homocysteine. *conversion to cysteine: ...
CK catalyses the conversion of creatine and utilizes adenosine triphosphate (ATP) to create phosphocreatine (PCr) and adenosine ... regeneration of methionine: Methionine synthase/Homocysteine methyltransferase. *Betaine-homocysteine methyltransferase. * ...
Adenosine deaminase (EC 3.5.4.4). *GTP cyclohydrolase I (EC 3.5.4.16). *Category:EC 3.5.5 (In nitriles) *Nitrilase (EC 3.5.5.1) ... S-adenosyl-L-homocysteine hydrolase. *Alkenylglycerophosphocholine hydrolase. *Alkenylglycerophosphoethanolamine hydrolase. * ...
... is also produced by the transsulfuration pathway, which converts homocysteine into cystathionine. The cystathionine is ...
Betaine-homocysteine S-methyltransferase. *Bile acid:sodium symporter. *Biliverdin reductase. *Biotin attachment domain ... Adenosine deaminase. *Adenosylmethionine decarboxylase. *Adenylosuccinate synthase. *AdoMet MTase. *Adrenocorticotropic hormone ...
regeneration of methionine: Methionine synthase/Homocysteine methyltransferase. *Betaine-homocysteine methyltransferase. * ... Adenosine antagonists. *8-Chlorotheophylline. *8-Cyclopentyltheophylline. *8-Phenyltheophylline. *Aminophylline. *Caffeine. * ...
AMPD2 adenosine monophosphate deaminase 2 [ Homo sapiens (human) ]». Gene. NCBI. 4. juni 2017. Henta 26. juni 2017.. ... MTR 5-methyltetrahydrofolate-homocysteine methyltransferase [ Homo sapiens (human) ]». Gene. NCBI. 4. juni 2017. Henta 26. juni ...
... and adenosine (Ado) are methionine metabolism intermediates that may act synergistically in certain disease. In this study, we ... Synergistic effects of homocysteine, S-adenosylhomocysteine and adenosine on apoptosis in BV-2 murine microglial cells Issue ... Keywords: Homocysteine, S-adenosylhomocysteine, adenosine, apoptosis, synergy. Journal: BioFactors, vol. 34, no. 2, pp. 81-95, ... Abstract: Homocysteine (Hcy), S-adenosylhomocysteine (SAH) and adenosine (Ado) are methionine metabolism intermediates that may ...
Adenosylhomocysteinase converts SAH into homocysteine and adenosine. Finkelstein, J. D. (2000). "Pathways and regulation of ... S-Adenosyl-l-homocysteine (SAH) is the biosynthetic precursor to homocysteine. SAH is formed by the demethylation of S-adenosyl ... BioCYC E.Coli K-12 Compound: S-adenosyl-L-homocysteine v t e. ... homocysteine metabolism in mammals". Semin. Thromb. Hemost. 26 ... Potential Epigenetic Mechanism for Homocysteine-Related Pathology". The Journal of Nutrition. 132 (8): 2361S-2366S. doi:10.1093 ...
The adenosine is then hydrolyzed to yield L-homocysteine. L-Homocysteine has two primary fates: conversion via tetrahydrofolate ... Homocysteine MS Spectrum Homocysteine at Lab Tests Online Homocysteine: analyte monograph[permanent dead link] - The ... Homocysteine is biosynthesized naturally via a multi-step process. First, methionine receives an adenosine group from ATP, a ... Homocysteine also acts as an allosteric antagonist at Dopamine D2 receptors. It has been proposed that both homocysteine and ...
ABBREVIATIONS: AdoHcy, S-adenosyl-l-homocysteine; Ado, adenosine; Hcy, homocysteine; IL, interleukin; DNFB, 2,4- ... S-Adenosyl-l-homocysteine Hydrolase Inactivation Curtails Ovalbumin-Induced Immune Responses. Yun-Feng Fu, Jun-Xia Wang, Yang ... S-Adenosyl-l-homocysteine Hydrolase Inactivation Curtails Ovalbumin-Induced Immune Responses. Yun-Feng Fu, Jun-Xia Wang, Yang ... S-Adenosyl-l-homocysteine Hydrolase Inactivation Curtails Ovalbumin-Induced Immune Responses. Yun-Feng Fu, Jun-Xia Wang, Yang ...
ATP, adenosine triphosphate; ADP, adenosine diphosphate; SAM, S-adenosine-l-methionine; SAH, S-adenosyl-l-homocysteine; NADP+, ...
... adenosine deaminase; albumin; alpha-fetoprotein; amino acid profiles (arginine (Krebs cycle), histidine/urocanic acid, ... homocysteine, phenylalanine/tyrosine, tryptophan); andrenostenedione; antipyrine; arabinitol enantiomers; arginase; ...
... adenosine deaminase; albumin; alpha-fetoprotein; amino acid profiles (arginine (Krebs cycle), histidine/urocanic acid, ... homocysteine, phenylalanine/tyrosine, tryptophan); andrenostenedione; antipyrine; arabinitol enantiomers; arginase; ...
... adenosine deaminase; albumin; alpha-fetoprotein; amino acid profiles (arginine (Krebs cycle), histidine/urocanic acid, ... homocysteine, phenylalanine/tyrosine, tryptophan); andrenostenedione; antipyrine; arabinitol enantiomers; arginase; ...
... adenosine deaminase; albumin; alpha-fetoprotein; amino acid profiles (arginine (Krebs cycle), histidine/urocanic acid, ... homocysteine, phenylalanine/tyrosine, tryptophan); andrenostenedione; antipyrine; arabinitol enantiomers; arginase; ...
Hydrolysis of s-adenosyl-homocysteine also contributes to intracellular adenosine formation [58, 59]. Extracellular adenosine ... adenosine kinase (ADK), which phosphorylates adenosine to AMP and is an important regulator of intracellular adenosine levels; ... Similarly to NO, adenosine is a potent vasodilator produced by adenine nucleotide degradation. Adenosine is predominantly ... have studied adenosine levels in the penis of sickle cell mice and have found a significant increase in adenosine levels, ...
... which converts S-adenosylhomocysteine to homocysteine and adenosine. Adenosine kinase (ADK; E.C.2.7.1.20) is not a direct part ... Adenosine kinase deficiency. Diagnosis. Selective screening. The clinical presentation of adenosine kinase deficiency (ADK ... Further therapeutic options yet to be explored are alternative degradation of adenosine via adenosine deaminase (ADA), which is ... It catalyzes the phosphorylation of adenosine to adenosine monophosphate and its deficiency causes the accumulation of ...
S-adenosylhomocysteine (SAH) hydrolase catalyzes conversion of homocysteine to SAH in the presence of added adenosine. The ... LB2HCY - Homocysteine (umol/L). Variable Name: LB2HCY. SAS Label: Homocysteine (umol/L). English Text: Homocysteine (umol/L). ... DTT reduces homocysteine bound to albumin and to other small molecules, homocysteine, and mixed disulfides, to free thiol. ... the Abbott Homocysteine assay was used as the primary method for determination of plasma total homocysteine in NHANES 1999-2000 ...
S-adenosylhomocysteine (SAH) hydrolase catalyzes conversion of homocysteine to SAH in the presence of added adenosine. The ... LBXHCY - Homocysteine (umol/L). Variable Name: LBXHCY. SAS Label: Homocysteine (umol/L). English Text: Homocysteine(umol/L). ... Total homocysteine (tHcy) in plasma is measured by the Abbott Homocysteine assay on the Abbott AxSym analyzer, a fully ... DTT reduces homocysteine bound to albumin and to other small molecules, homocysteine, and mixed disulfides, to free thiol. ...
Elevation in S-adenosylhomocysteine and DNA hypomethylation: potential epigenetic mechanism for homocysteine-related pathology ... Decrease of adenosine A1 receptor density and of adenosine neuromodulation in the hippocampus of kindled rats. Eur J Neurosci. ... Boison D. Adenosine as a modulator of brain activity. Drug News Persp. 2007;20(10):607-611.. View this article via: PubMed ... Adenosine signalling and function in glial cells. Cell Death Differ. 2010;17(7):1071-1082.. View this article via: PubMed ...
Adenosine Triphosphate; IMP: Ionosine Monophosphate; AMP: Adenosine Monophosphate; ADP: Adenosine Diphosphate; Pi: Inorganic ... TAS: Total Antioxidant Status; UA: Uric Acid TBIL: Total Bilirubine; Hcy: Homocysteine; SCN: Suprachiasmatic Nuclei; MVC: ... Adenosine diphosphate (ADP), adenosine monophosphate (AMP), and ionosine monophosphate (IMP) have much lower affinity for Mg2+ ... 2007) Daily variations of homocysteine concentration may influence methylation of DNA in normal healthy individuals. Chronobiol ...
... s-adenosyl-l-homocysteine; amet, s-adenosyl-l-methionine; atp, adenosine-3-phosphate; co2, carbon dioxide; h, hydrogen; h2o, ...
Effects of L-methionine, L-homocysteine, and adenosine. J. Biol. Chem. 255, 10822-10827.PubMedGoogle Scholar ...
Finally, plasma homocysteine concentration needs to be considered as a determinant of adenosine-induced vasodilatation. MTX ... adenosine deaminase activity is also reduced, resulting in an increased adenosine concentration which can stimulate adenosine ... and extracellularly by degradation of adenosine monophosphate (AMP) (fig 1).4 Degradation of adenosine by the enzymes adenosine ... For determination of adenosine deaminase activity, adenosine was added to lysate in a final concentration of 0, 25, 50, 100, ...
AdoHcy is then converted into adenosine and homocysteine by AdoHcy hydrolase. DZNep and adenosine dialdehyde inhibit AdoHcy ... For example, adenosine dialdehyde, which is less potent than DZNep, may not metabolically survive because of the two labile ... Cells were then treated with 1 to 5 μmol/L DZNep (17), 10 to 100 μmol/L adenosine dialdehyde (Sigma), 50 to 150 μmol/L ... Effects of adenosine dialdehyde on S-adenosylhomocysteine hydrolase and S-adenosylmethionine-dependent transmethylations in ...
Supplementary test information for Cobalamin/Propionate/Homocysteine Metabolism Related Disorders Panel such as test ... Disorders of cobalamin (vitamin B12)/propionate/homocysteine metabolism result from defects in the vitamin B12 metabolic ... Cobalamin/Propionate/Homocysteine Metabolism Related Disorders Panel, Sequencing and Deletion/Duplication 2011157 ... Confirm suspected cobalamin (vitamin B12)/propionate/homocysteine metabolism-related disorder in individuals with clinical ...
SAM-e is produced in the human body from adenosine triphosphate and methionine. Oral supplementation is used primarily to ... SAM-e is endogenously produced in the human body from adenosine triphosphate and methionine (1) (2). It is involved in the ... Homocysteine is formed through the transsulfuration pathway and is catabolized to cysteine and indirectly to glutathione. ... Increase of serum homocysteine: In some patients with AIDS-associated myelopathy (32). ...
Catalyzes the hydrolysis of AdoHcy to adenosine and homocysteine. AdoHcy hydrolysis serves not only to sustain the flux of ... The product the BHMT gene is central to the short cut through the methylation cycle, again helping to convert homocysteine to ... The C677T mutation is associated with a general set of problems: elevated homocysteine, increase in heart disease, increased ... Helps produce methionine from homocysteine. Likely needs a methylated B12. A mutation here causes increase function and ...
AHCY converts the methionine substrate S-adenosylhomocysteine (SAH) to adenosine and homocysteine. This reaction is an ... The adverse effects of homocysteine accumulation in the body are related to the substitution of homocysteine for methionine in ... The accumulation of homocysteine, which is caused by mutations in this pathway, has been directly linked to oxidative stress ... Betaine-homocysteine methyltransferase (BHMT) and BHMT2 are the only enzymes that can metabolize betaine. This reaction is ...
... hydrolase controls the step that converts the compound S-adenosylhomocysteine to the compounds adenosine and homocysteine. This ...
First it is donated to homocysteine (a rxn requiring B12) to make methionine. Then an adenosine base is added to make SAM. SAM ...
High homocysteine levels. Homocysteine is an amino acid produced by the body by chemically altering adenosine. Amino acids are ... High levels of homocysteine have been linked to an increased risk of heart attacks and strokes. Most labs report normal ranges ... of homocysteine as about 4-15 µml/L.. • Folate deficiency causing extreme chronic fatigue, light-headedness and forgetfulness. ...
In the present study, homocysteine, cortisol, adenosine deaminase (. ADA. ), ferritin, malondialdehyde (MDA) and α-tocopherol ... RA group showed a significant increase in the levels of homocysteine, ADA. and MDA, and a significant decrease in α-tocopherol ...
In the present study, homocysteine, cortisol, adenosine deaminase (ADA), ferritin, malondialdehyde (MDA) and -tocopherol in ... RA group showed a significant increase in the levels of homocysteine, ADA and MDA, and a significant decrease in α-tocopherol ...
S-ADENOSYL-L-HOMOCYSTEINE HYDROLASE. A, B, C, D, E, F, G, H. 431. Rattus norvegicus. Mutation(s): 0 Gene Names: Ahcy. EC: 3.3. ... Inhibition of S-adenosylhomocysteine Hydrolase by acyclic sugar Adenosine Analogue D-eritadenine. *DOI: 10.2210/pdb1K0U/pdb ... D-eritadenine (DEA) is a potent inhibitor (IC(50) = 7 nm) of S-adenosyl-l-homocysteine hydrolase (AdoHcyase). Unlike cyclic ... D-eritadenine (DEA) is a potent inhibitor (IC(50) = 7 nm) of S-adenosyl-l-homocysteine hydrolase (AdoHcyase). Unlike cyclic ...
Yasko Methylation Catalyzes the hydrolysis of AdoHcy to adenosine and homocysteine. AdoHcy hydrolysis serves not only to ...
  • Abnormally high levels of homocysteine in the serum, above 15 μmol/L, are a medical condition called hyperhomocysteinemia. (wikipedia.org)
  • High levels of homocysteine have been linked to an increased risk of heart attacks and strokes. (amoils.com)
  • RA group showed a significant increase in the levels of homocysteine, ADA and MDA, and a significant decrease in α-tocopherol compared to the healthy individuals. (niscair.res.in)
  • When you have poor methylation your body's levels of homocysteine will elevate. (anabolicminds.com)
  • Dr. Kilmer McCulley (author of 'The Homocysteine Revolution'), discovered that high levels of homocysteine caused heart disease and stroke in animal studies. (anabolicminds.com)
  • Researchers have not determined how altered levels of homocysteine and methionine lead to the various health problems affecting multiple parts of the body in people with homocystinuria. (medlineplus.gov)
  • T polymorphism, particularly those with the genetic change in both copies of the gene, have elevated levels of homocysteine in their blood (hyperhomocysteinemia) resulting from the reduced activity of methylenetetrahydrofolate reductase. (medlineplus.gov)
  • Elevated levels of homocysteine and S-adenosylmethionine are causal risk factors for several neurological disorders. (biomedsearch.com)
  • We have identified 135 genes in 1137 abstracts that either modulate the levels of homocysteine or are modulated by elevated levels of homocysteine. (biomedcentral.com)
  • Elevated levels of homocysteine also decreases the bioavailability of nitric oxide and modulates the levels of other metabolites including S-adenosyl methionine and S-adenosyl homocysteine which may result in cardiovascular or neurological disorders. (biomedcentral.com)
  • The ER stress emerges as the common pathway that relates to apoptosis, atherosclerosis and neurological disorders and is modulated by levels of homocysteine. (biomedcentral.com)
  • However, genetic defects or nutritional deficiencies lead to elevation of the levels of homocysteine. (biomedcentral.com)
  • These are methionine adenosyltransferase I/III, glycine N-methyltransferase, S-adenosylhomocysteine hydrolase and adenosine kinase deficiencies. (springer.com)
  • A low-methionine diet can be beneficial in patients with methionine adenosyltransferase I/III deficiency if plasma methionine concentrations exceed 800 μmol/L. There is some evidence that this diet may also be beneficial in patients with S-adenosylhomocysteine hydrolase and adenosine kinase deficiencies. (springer.com)
  • S-adenosylhomocysteine (SAH) hydrolase catalyzes conversion of homocysteine to SAH in the presence of added adenosine. (cdc.gov)
  • Specifically, S-adenosylhomocysteine hydrolase controls the step that converts the compound S-adenosylhomocysteine to the compounds adenosine and homocysteine. (medlineplus.gov)
  • D-eritadenine (DEA) is a potent inhibitor (IC(50) = 7 nm) of S-adenosyl-l-homocysteine hydrolase (AdoHcyase). (rcsb.org)
  • SAH is hydrolyzed to form homocysteine (Hcy) and adenosine through a reversible reaction catalyzed by SAH hydrolase, whose thermodynamics favors biosynthesis rather than hydrolysis. (nih.gov)
  • S-Adenosylhomocysteine (AdoHcy) hydrolase regulates all adenosylmethionine-(AdoMet) dependent transmethylations by hydrolyzing the potent feedback inhibitor AdoHcy to homocysteine and adenosine. (nih.gov)
  • Molecular cloning, characterization and expression analysis of S- adenosyl- L-homocysteine hydrolase (SAHH) during the pathogenic infection of Litopenaeus vannamei by Vibrio alginolyticus. (bioportfolio.com)
  • The inactivation of AdoHcy hydrolase by ara-A in rat hepatocytes was inhibited in the presence of adenosine or homocysteine in the cellular medium. (aacrjournals.org)
  • ADO also has receptor-independent effects, because extracellular adenosine can cross the cell membrane and activate AMP-activated protein kinase (AMPK), adenosine kinase, and S-adenosyl homocysteine hydrolase pathways [ 2 ]. (hindawi.com)
  • Intracellular production of adenosine is directly dependent (30%) on the hydrolysis of S-adenosylhomocysteine (SAH) by S-adenosylhomocysteine hydrolase in methionine cycle. (clinicaltrials.gov)
  • During these reactions SAM is converted by various methyl transferases to S-adenosyl homocysteine (SAH), which is then hydrolyzed to homocysteine and adenosine by S-adenosyl homocysteine hydrolase. (biomedcentral.com)
  • This is hydrolysed to homocysteine and adenosine by S-adenosylhomocysteine hydrolase EC 3.3.1.1 and the homocysteine recycled back to methionine through transfer of a methyl group from 5-methyltetrahydrofolate, by one of the two classes of methionine synthases EC 2.1.1.13 or EC 2.1.1.14. (bayho.com)
  • S-adenosyl-L-homocysteine (AdoHcy) hydrolase effects hydrolytic cleavage of AdoHcy to produce both adenosine and L-homocysteine and is a feedback inhibitor of S-adenosyl-L-methionine (SAM). (fiu.edu)
  • Homocysteine (Hcy), S-adenosylhomocysteine (SAH) and adenosine (Ado) are methionine metabolism intermediates that may act synergistically in certain disease. (iospress.com)
  • Confirm suspected cobalamin (vitamin B 12 )/propionate/homocysteine metabolism-related disorder in individuals with clinical symptoms and/or biochemical findings. (arupconsult.com)
  • Disorders of cobalamin (vitamin B 12 )/propionate/homocysteine metabolism result from defects in the vitamin B 12 metabolic pathway. (arupconsult.com)
  • Molecular testing is used to confirm suspected cobalamin/propionate/homocysteine metabolism-related disorder in individuals with clinical symptoms and/or biochemical findings. (arupconsult.com)
  • Defects of absorption, transport, and intracellular metabolism of cobalamin/propionate/homocysteine lead to accumulation of methylmalonic acid, methionine, and/or homocysteine in blood and urine. (arupconsult.com)
  • Lignin, maize, methylenetetrahydrofolate reductase, methyl metabolism, S-adenosyl homocysteine, S-adenosyl methionine Introduction Maize (Zea mays L.) originated in Central America and is one of the most widely grown crops in the world. (deepdyve.com)
  • Homocysteine metabolism. (wikipathways.org)
  • Several human genetic rare diseases are also associated with homocysteine (Hcy) metabolism and SNHL confirming this potential link. (frontiersin.org)
  • Disorders in the maternal-fetal homocysteine (Hcy) metabolism due to folate and/or cobalamin deficiencies are related to a wide array of pathological conditions, such as recurrent miscarriages, placental abruption, preeclampsia, neural tube closure defects and intrauterine growth retardation [9-13]. (thefreelibrary.com)
  • Ras proteins, nitrosylation and homocysteine metabolism. (biomedsearch.com)
  • Besides, our results suggest that in conditions of a low level of nitric oxide PC12 cells with mutated oncogenic Ras produce more ROS than cells with wild type Ras and switch homocysteine metabolism toward to transsulfuration. (biomedsearch.com)
  • Mapping the genes to their respective pathways revealed that an elevated level of homocysteine leads to the atherosclerosis either by directly affecting lipid metabolism and transport or via oxidative stress and/or Endoplasmic Reticulum (ER) stress. (biomedcentral.com)
  • Homocysteine, a thiol containing amino acid, is formed during methionine metabolism in the cell. (biomedcentral.com)
  • The essential steps that contribute to the metabolism of homocysteine are outlined in (Figure 1 ). (biomedcentral.com)
  • In healthy well nourished individuals homocysteine metabolism is well regulated and the plasma concentration is usually less than 12 μM. (biomedcentral.com)
  • To complicate matters, some individuals have an inborn error of folate or methyl metabolism, in that they show a defect in the enzyme that converts homocysteine to methionine, and thus produce insufficient amounts of SAMe. (dynamicchiropractic.com)
  • Although abnormal metabolism of methionine and homocysteine has been associated with other neurologic diseases, these pathways have not been evaluated in persons with autism. (avn.org.au)
  • At these time points, the activity of adenosine deaminase was measured in isolated lymphocytes, and forearm blood flow (FBF) was determined by venous occlusion plethysmography during administration of adenosine and dipyridamole into the brachial artery. (bmj.com)
  • 4 Degradation of adenosine by the enzymes adenosine deaminase and adenosine kinase, however, is confined to the intracellular compartment. (bmj.com)
  • This assay utilizes SAHH to hydrolyze the methyltransfer product S-adenosylhomocysteine to homocysteine and adenosine in the presence of adenosine deaminase which converts adenosine to inosine. (selleckchem.com)
  • For IC50 determinations, assay mixtures are prepared in 25 mM Potassium Phosphate buffer pH 7.5, 1 mM EDTA, 2 mM MgCl 2 , 0.01% Triton X 100 with 5 μM SAHH , 0.3 U/mL of adenosine deaminase, 25 μM SAM, and 15 μM ThioGlo. (selleckchem.com)
  • Vitamin B12 deficiency, when coupled with high serum folate levels, has been found to increase overall homocysteine concentrations as well. (wikipedia.org)
  • Plasma total homocysteine concentrations are calculated by the Abbott AxSym Immunoassay Analyzer using a machine-stored calibration curve. (cdc.gov)
  • Animal studies suggest that the anti-inflammatory effect of methotrexate (MTX) is mediated by increased adenosine concentrations. (bmj.com)
  • Tanghe, K.A., Garrow, T.A. and Schalinske, K.L. (2004) Triiodothyronine Treatment Attenuates the Induction of Hepatic Glycine N-Methyltransferase by Retinoic Acid and Elevates Plasma Homocysteine Concentrations in Rats. (scirp.org)
  • Vitamin B-6 and folic acid have long been known to support cardiac health by promoting normal blood pressure and helping to reduce bodily concentrations of homocysteine. (chiroeco.com)
  • Design: Plasma concentrations of methionine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), adenosine, homocysteine, cystathionine, cysteine, and oxidized and reduced glutathione were measured in 20 children with autism and in 33 control children. (avn.org.au)
  • Results: Relative to the control children, the children with autism had significantly lower baseline plasma concentrations of methionine, SAM, homocysteine, cystathionine, cysteine, and total glutathione and significantly higher concentrations of SAH, adenosine, and oxidized glutathione. (avn.org.au)
  • Yasko Methylation Catalyzes the hydrolysis of AdoHcy to adenosine and homocysteine. (snpedia.com)
  • This effect of homocysteine correlated with increased cellular level of AdoHcy induced by this agent but was also associated with reduction in cellular uptake of ara-A. (aacrjournals.org)
  • It catalyzes the reversible hydrolysis of S-adenosylhomocysteine (AdoHcy) to adenosine (Ado) and L-homocysteine (Hcy). (bio-rad.com)
  • Furthermore, MTHFR mutation did not change the content of S-adenosyl methionine (SAM), the methyl group donor involved in the biosynthesis of guaiacyl and syringyl lignins, but increased the level of S-adenosyl homocysteine (SAH), the demethylation product of SAM. (deepdyve.com)
  • After donating a methyl group, SAMe is converted to S-adenosyl-homocysteine. (nutraceuticalsworld.com)
  • Methylation occurs when SAMe (S-adenosine methionine) donates a methyl group, which is then attached to the molecule that is being detoxified. (anabolicminds.com)
  • Folate (folic acid, a B vitamin) is unique in that it contains a methyl group (CH3), which it donates to homocysteine to permit its enzymatic conversion to methionine. (dynamicchiropractic.com)
  • Trimethylglycine / betaine donates a methyl group to convert homocysteine to methionine in a reaction catalysed by BHMT (Betaine Homocysteine Methyltransferase, E.C. 2.1.1.5, a zinc metalloenzyme). (bayho.com)
  • Hcy can be remethylated to form methionine via methionine synthase (MS), which requires folate and vitamin B 12 and betaine homocysteine methyltransferase, which requires betaine. (nih.gov)
  • This is the primary form of folate found in blood, and is necessary for the multistep process that converts the amino acid homocysteine to another amino acid, methionine. (medlineplus.gov)
  • 1-3 ] In addition, because of its actions on membrane ion conductances and intracellular metabolic signaling in neurons and glial cells, adenosine exerts neuroprotective effects attenuating the toxic release of excitatory amino acids and excessive intracellular accumulation of free ionic calcium. (asahq.org)
  • Adenosine (ADO) is a nucleoside with pleiotropic functions, which acts as an intracellular and extracellular mediator of multiple biological processes. (hindawi.com)
  • However, studies show that these individuals can improve the conversion of homocysteine to methionine significantly if they are provided with higher supplementation levels of folic acid (which is the coenzyme for this reaction) in many cases. (dynamicchiropractic.com)
  • TMG (trimethylglycine), also known as anhydrous betaine, is found in a variety of plant and animal sources and is used in the conversion of homocysteine to methionine. (bayho.com)
  • A high level of homocysteine in the blood (hyperhomocysteinemia) makes a person more prone to endothelial cell injury, which leads to inflammation in the blood vessels, which in turn may lead to atherogenesis, which can result in ischemic injury. (wikipedia.org)
  • These genes were then placed in appropriate pathways in an attempt to understand the molecular basis of homocysteine induced complex disorders and to provide a resource for selection of genes for polymorphism screening and analysis of mutations as well as epigenetic modifications in relation to hyperhomocysteinemia. (biomedcentral.com)
  • Because of this "self-looping" reaction, homocysteine-containing peptides tend to cleave themselves by reactions generating oxidative stress. (wikipedia.org)
  • Memory impairment has been shown to be associated with glutamate (Glu) excitotoxicity, homocysteine (Hcy) accumulation, and oxidative stress. (mdpi.com)
  • We conclude that trophic factor withdrawal stimulates Ras, which apparently through the Rac/NADPH oxidase system induces permanent oxidative stress, modulates the activities of NF-kB and c-Fos, induces production of homocysteine and accelerates apoptosis. (biomedsearch.com)
  • Total homocysteine (tHcy) in plasma is measured by the Abbott Homocysteine assay on the Abbott AxSym analyzer, a fully automated FPIA method. (cdc.gov)
  • In this context, different epidemiological studies have shown correlations among the nutritional condition, increased total plasma homocysteine (tHcy) and SNHL. (frontiersin.org)
  • 1% of homocysteine is present in the free reduced form, while 10-20 % of the tHcy is present as homocysteine-cysteine mixed disulfide and homocystine (dimer of homocysteine), 80-90 % of homocysteine in circulation is protein bound [ 10 ]. (biomedcentral.com)
  • Adenosylhomocysteinase converts SAH into homocysteine and adenosine. (wikipedia.org)
  • Homoserine converts to O -succinyl homoserine, which then reacts with cysteine to produce cystathionine, which is cleaved to yield homocysteine. (newworldencyclopedia.org)
  • This review summarizes the signaling pathways of FAK in prevention of apoptosis and the role of FAK in mediating adenosine and homocysteine-induced endothelial cell apoptosis and in cardiovascular diseases. (nih.gov)
  • In contrast, A2A and A2B receptors are coupled with G proteins Gs or Gq and activate adenylyl cyclase or phospholipase C. Moreover, all adenosine receptors activate mitogen-activated protein kinase (MAPK) pathways, which include extracellular signal regulated kinase 1 (ERK1), ERK2, Jun N-terminal kinase, and p38 MAPK. (hindawi.com)
  • While there are a large number of independent studies implicating homocysteine in isolated pathways, the mechanism of homocysteine induced adverse effects are not clear. (biomedcentral.com)
  • To assess the effect of MTX on the vasodilator effects of adenosine and the nucleoside uptake inhibitor, dipyridamole, in humans in vivo as a marker for changes in adenosine kinetics. (bmj.com)
  • We found that under serum and nerve growth factor withdrawal conditions undifferentiated apoptotic M-CR3B cells accumulated more homocysteine, than M-M17-26 cells and the production of homocysteine decreased under the action of manumycin (inhibitor of farnesyltransferase) and increased in the presence of L-NAME (inhibitor of nitric oxide synthase). (biomedsearch.com)
  • Further biochemical measurements proved that RS and RLs were able to lower plasma C-reactive protein, homocysteine and asymmetric dimethylarginine levels. (dovepress.com)
  • PC12 pheochromocytoma cells expressing a dominant inhibitory mutant of Ha-ras (M-M17-26, PC12 pheochromocytoma cells expressing a mutant v-ras gene (MVR) and PC12 cells transfected with normal c-rasH (M-CR3B) has been used to investigate the role of nitrosylation and farnesylation of Ras on the production of homocysteine and the activities of the redox-sensitive transcription factors NF-kB and c-Fos. (biomedsearch.com)
  • Other potential interactions between this 2 metabolisms in AF are: 1) ratio SAM/SAH influences epigenetic mechanisms that can modify the expression of candidate genes involved in synaptic transmission and potassium canals, 2) ratio SAM/SAH influences also the cellular production of homocysteine with effects on cellular polarization, 3) adenosine and homocysteine are factors involved in thrombophilia and potentially associated to thromboembolic complications of AF. (clinicaltrials.gov)
  • First, methionine receives an adenosine group from ATP, a reaction catalyzed by S-adenosyl-methionine synthetase, to give S-adenosyl methionine (SAM). (wikipedia.org)
  • It is formed in the body from methionine and adenosine triphosphate in a reaction catalyzed by methionine adenosyltransferase. (nutraceuticalsworld.com)
  • There are several objectives of this project, including determining whether long-term dietary methyl supplementation or SAMe supplementation in rats will effect changes in longevity, in age-related pathology, and in such molecular parameters as dna methylation, SAMe, a reaction product of SAMe called S-adenosylhomocysteine (sah), and homocysteine, the most important biochemical risk factor for vascular disease (Frankel & Mitchell 1997). (lifeextension.com)
  • In vivo , this reaction proceeds as hydrolysis because the products Hcy and adenosine are promptly removed. (nih.gov)
  • Remethylation of homocysteine via MS requires 5-methyltetrahydrofolate (5-MTHF), which is derived from 5,10-methylenetetrahydrofolate (5,10-MTHF) in a reaction catalyzed by methylenetetrahydrofolate reductase (MTHFR). (nih.gov)
  • S-adenosyl-l-methionine (SAM or SAMe) is a compound that is formed from a reaction of methionine and adenosine triphosphate (ATP). (newworldencyclopedia.org)
  • S-adenosylmethionine (SAM) has been shown to provoke repression of some methionine-specific enzymes in wild-type cells, namely, adenosine triphosphate sulfurylase, sulfite reductase, and homocysteine synthetase. (eurekamag.com)
  • Several studies have also suggested that the beneficial effects of adenosine occur through the effects of the A2AR and A2BR ( 7 , 22 , 27 , 43 ). (physiology.org)
  • At 24h after transfection, cells were incubated in buffer alone (HBS, vehicle) or with 1 mM adenosine (Ado) or 100 μM adenosine plus 100 μM homocysteine (Ado/HC) for additional 16 h and then apoptosis was assessed by Hoechst staining. (nih.gov)
  • Adenosine is a purine-nucleoside that is formed both intra- and extracellularly by degradation of adenosine monophosphate (AMP) (fig 1). (bmj.com)
  • Cyclic adenosine 3',5'-monophosphate inhibits the availability of arachidonate to prostaglandin synthetase in human platelet suspensions. (wikipathways.org)
  • In this study, we aimed to examine the association between homocysteine (HCY), vitamin B 12 (B12), folic acid (FA) and ED. (bmj.com)
  • According to the changes in the homocysteine (HCY), vitamin B 12 (B12) and folic acid (FA) levels, and the order of erectile dysfunction (ED) severity, we investigated the associations between HCY, B12, FA and ED. (bmj.com)
  • Vitamin B6, B12, and folic acid are necessary to reduce homocysteine and keep the methylation process occurring. (anabolicminds.com)
  • Inherited methylation disorders are a group of rarely reported, probably largely underdiagnosed disorders affecting transmethylation processes in the metabolic pathway between methionine and homocysteine. (springer.com)
  • o The amount of homocysteine (Poor methylation leads to higher amounts)is a good indicator of how 'biologically old' a person is (as opposed to chronological age). (anabolicminds.com)
  • Homocysteine-induced modulation of gene expression through alteration of methylation status or by hitherto unknown mechanisms is predicted to lead to several pathological conditions either directly or indirectly. (biomedcentral.com)
  • HPLC-FD, HPLC-ED, and GC/MS). Thus, the Abbott Homocysteine assay was used as the primary method for determination of plasma total homocysteine in NHANES 2003-2004. (cdc.gov)
  • ABSTRACT: An increase in total homocysteine (Hcy) levels (protein-bound and free Hcy in the serum) has been identified as a risk factor for vascular diseases. (scirp.org)
  • We have recently shown that extracellular adenosine enhances human pulmonary (EC) barrier via activation of adenosine receptors (ARs) in cell cultures. (physiology.org)
  • We found that the production of ADMA by human endothelial cells is upregulated in the presence of methionine or homocysteine and inhibited by either of the methyltransferase inhibitors S-adenosylhomocysteine, adenosine dialdehyde, or cycloleucine. (fraunhofer.de)
  • Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in the remethylation of homocysteine to methionine. (iospress.com)
  • Formed homocysteine is either catabolized into cystathionine (transsulfuration pathway) by cystathionine beta-synthase, or remethylated into methionine (remethylation pathway) by methionine synthase. (biomedsearch.com)
  • The A2AR is expressed in lung tissues, where it is activated by endogenous/exogenous adenosine or A2AR agonists and where it exerts anti-inflammatory effects ( 24 , 39 , 45 ). (physiology.org)
  • The comprehensive network collated has lead to the identification of genes that are modulated by homocysteine indicating that homocysteine exerts its effect not only through modulating the substrate levels for various catalytic processes but also through regulation of expression of genes involved in complex diseases. (biomedcentral.com)
  • RNA N6-methyltransferase that methylates adenosine residues at the N(6) position of a subset of RNAs and is involved in S-adenosyl-L-methionine homeostasis by regulating expression of MAT2A transcripts (PubMed:28525753, PubMed:30197299, PubMed:30197297). (genecards.org)
  • Both cystathionine-γ-synthase and cystathionine-β-lyase require Pyridoxyl-5'-phosphate as a cofactor, whereas homocysteine methyltransferase requires Vitamin B 12 as a cofactor (Lehninger 2000). (newworldencyclopedia.org)
  • 5 There are four types of G-protein coupled adenosine receptor, which are designated A 1 , A 2A , A 2B , and A 3 receptors. (bmj.com)
  • Furthermore, adenosine significantly attenuated protein degradation of A2A and A3 receptors induced by LPS. (physiology.org)
  • The protein encoded by this gene interacts with inositol 1,4,5-trisphosphate receptor, type 1 and may be involved in the conversion of S-adenosyl-L-homocysteine to L-homocysteine and adenosine. (thermofisher.com)
  • SAHH is an enzyme, playing a significant role in the catalyzation of the S-adenosyl homocysteine (SAH) into homocysteine (Hcy) and adenosine (Ado). (bioportfolio.com)
  • Mammals biosynthesize the amino acid cysteine via homocysteine. (wikipedia.org)
  • Rabbit anti S-adenosyl homosysteine antibody recognizes S-Adenosyl Homocysteine, an intermediate in the synthesis of the amino acid cysteine. (bio-rad-antibodies.com)
  • Homocysteine once formed can either be remethylated to methionine by methionine synthase (MS) or betaine hydroxymethyl transferase (BHMT) and/or converted to cystathionine by cystathionine-beta-synthase (CBS). (biomedcentral.com)
  • Without functional methylenetetrahydrofolate reductase, homocysteine cannot be converted to methionine. (medlineplus.gov)
  • An unusual dual role for a catalytic water molecule in the active site is revealed in the complex with the adenosine analog 2'-hydroxy, 3'-ketocyclopent-4'-enyladenine. (nih.gov)
  • Adenosine (ADO) is an immunosuppressive molecule, which suppresses the immune responses by interacting with specific receptors expressed by immune effector cells. (hindawi.com)
  • Magnesium aids in the production of adenosine triphosphate (ATP), the main energy storage and transfer molecule in the cell. (chiroeco.com)
  • Third, both nutrient groups help convert food into the unique molecule (adenosine triphosphate or ATP) that all cells use for energy, especially fuel-hungry brain cells. (nutritionexpress.com)
  • Homocysteine also acts as an allosteric antagonist at Dopamine D2 receptors. (wikipedia.org)
  • Adenosine is a cardiovascular modulator with effects on vascular tonus and activation of nodal tissue through the activation of A1, A2A, A2B et A3 receptors. (clinicaltrials.gov)
  • Cellular production of adenosine depends on ratio SAH/S-adenosylmethionine (SAM) and modulates the expression of receptors. (clinicaltrials.gov)
  • Methionine is then converted to SAMe by Methionine Adenosyl Transferase (MAT) using magnesium and adenosine triphosphate as co-factors. (bayho.com)
  • Homocysteine can either be converted to glutathione or methylated to form methionine, thus forming the starting point for SAM synthesis and completing the cycle. (reactome.org)
  • This study will evaluate the genetic (micro SNP-array) and adenosine and methionine metabolic determinants in the physiopathology of AF in normal hearts. (clinicaltrials.gov)
  • As a breakdown product of ATP, adenosine is an endogenous purine nucleoside that modulates many physiological processes in all cells of the body. (physiology.org)
  • The nucleoside next to the terminal guanosine may be either guanosine or adenosine. (genome.jp)
  • Quinn CT, Griener JC, Bottiglieri T, Hyland K, Farrow A, Kamen BA (1997) Elevation of homocysteine and excitatory amino acid neurotransmitters in the CSF of children who receive methotrexate for the treatment of cancer. (springer.com)
  • Homocysteine is an independent risk factor for cardiovascular diseases. (biomedcentral.com)
  • Pulmonary artery endothelial cells (PAECs) were incubated in HEPES buffer in the absence (vehicle) or presence of 100 μM adenosine plus 100 μM homocysteine (Ado/HC) for 4 h. (nih.gov)
  • DTT reduces homocysteine bound to albumin and to other small molecules, homocysteine, and mixed disulfides, to free thiol. (cdc.gov)
  • The homocysteine concentration is then determined through conjugation of its free sulfhydryl moiety to a thiol-sensitive fluorophore, ThioGlo. (selleckchem.com)
  • 6,7 ] In the human brain, however, no data are available that characterize the role of adenosine and its metabolites during ischemia and reperfusion in patients. (asahq.org)
  • Two other drugs, sinefungin and adenosine dialdehyde, have similar effects as DZNep on H3K27me3. (aacrjournals.org)
  • Maintaining normal homocysteine levels is important for the health of the cardiovascular system. (bayho.com)