| folic acid antagonist | <pharmacology> A chemical which inhibits a cells capacity to use folic acid and so prevent cell division, for example methotrexate. See: chemotherapy. (12 Nov 1997) |
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| overdose | 1. To administer an excessive dose. 2. An excessive dose. (18 Nov 1997) |
| folic acid | <biochemistry> Pteridine derivative that is abundant in liver and green plants and is a growth factor for some bacteria. The biochemically active form is tetrahydrofolate (see folate). (12 Nov 1997) |
| folic acid antagonists | Inhibitors of the enzyme, dihydrofolate reductase (tetrahydrofolate dehydrogenase), which converts dihydrofolate (fh2) to tetrahydrofolate (fh4). They are frequently used in cancer chemotherapy. (12 Dec 1998) |
| folic acid conjugate | A folate with three molecules of glutamic acid (pteropterin) instead of one, or with seven (pteroylheptaglutamic acid or vitamin Bc conjugate). (05 Mar 2000) |
| folic acid deaminase | <enzyme> Chemotaxis regulating enzyme; splits folic acid into 6-hydroxymethylpterin and p-aminobenzoylglutamic acid Registry number: EC 3.5.4.- Synonym: folic acid inactivating enzyme, folic acid c9-n10 cleaving enzyme (26 Jun 1999) |
| folic acid deficiency | 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 anaemia, macrocytic anaemia, and megaloblastic anaemia. 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) (12 Dec 1998) |
| folic acid deficiency anaemia | Anaemia due to deficiency of folic acid, characterised by large-sized red blood cells (macrocytosis) and presence of large nuclei in erythroid precursor cells (megaloblasts) in the bone marrow. (05 Mar 2000) |
| folic acid oxidase | <enzyme> Enzyme from human red blood cell membranes; catalyses oxidation of folic acid to pterin-6-aldehyde plus p-aminobenzoylglutamic acid in presence of h2o2; singlet oxygen is involved Registry number: EC 1.11.- (26 Jun 1999) |
| aldosterone antagonist | An agent that opposes the action of the adrenal hormone aldosterone on renal tubular mineralocorticoid retention; these agents, e.g., spironolactone, are useful in treating the hypertension of primary hyperaldosteronism, or the sodium retention of secondary hyperaldosteronism. (05 Mar 2000) |
| antagonist | <pharmacology> A substance that tends to nullify the action of another, as a drug that binds to a cell receptor without eliciting a biological response. Origin: Gr. Antagonistes = an opponent (18 Nov 1997) |
| associated antagonist | One of two muscles or groups of muscles which pull in nearly opposite directions, but which, when acting together, move the part in a path between their diverging lines of action. (05 Mar 2000) |
| beta-adrenoreceptor antagonist | A class of drugs that compete with beta-adrenergic agonists for available receptor sites; some compete for both b1 and b2 receptors (e.g., propranolol) while others are primarily either b1 (e.g., metoprolol) or b2 blockers; used in the treatment of a variety of cardiovascular diseases where beta-adrenergic blockade is desirable. Synonym: beta-adrenergic receptor blocking agent, beta-adrenoreceptor antagonist, beta-blocker. (05 Mar 2000) |
| calcium antagonist | calcium channel-blocking agent |
| calcium channel antagonist | <pharmacology> A class of drugs that act by selective inhibition of calcium ion influx through or across cell membranes or on the release and binding of calcium in intracellular pools. Calcium channel blockers are used primarily in the treatment of certain heart conditions and stroke. As they are inducers of vascular and other smooth muscle relaxation, they are also used in the treatment of hypertension and cerebrovascular spasms, as myocardial protective agents, and in the relaxation of uterine spasms. Synonym: calcium antagonist, calcium channel-blocker, slow channel-blocking agent. (12 May 2002) |