| adenosine | <biochemistry> A ribonucleotide which consists of the nitrogenous base adenine linked to the sugar ribose. <drug> A cardiac drug used in terminating PSVT involving reentry pathways that include the AV node or Wolff-Parkinson-White syndrome. For atrial flutter, atrial fibrillation, atrial or ventricular tachycardias, adenosine may produce transient AV block that may help identify the rhythm. Pharmacologic action: Endogenous purine nucleoside that depresses AV node and sinus node activity. Brief duration of action (1-2 min). Dose: Rapid 6 mg IV bolus over 1-3 sec. May repeat at 12 mg IV bolus within 1-2 min Patients taking theophylline may require larger doses. Use a smaller dose with cardiac transplant patients. Potential complications: Common but transient - flushing, dyspnea, chest pain, bradycardia, and ventricular ectopy. Theophylline (and caffeine) blocks adenosine's effects. Dipyridamole potentiates adenosine's effects. Use other agents to avoid these drug interactions. (15 Mar 2000) |
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| adenosine 3',5'-cyclic monophosphate | An activator of phosphorylase kinase and an effector of other enzymes, formed in muscle from ATP by adenylate cyclase and broken down to 5'-AMP by a phosphodiesterase; sometimes referred to as the "second messenger." A related compound (2',3') is also known. Synonym: cyclic adenylic acid, cyclic AMP, cyclic phosphate. Acronym: cAMP (05 Mar 2000) |
| adenosine 3',5'-cyclic phosphate phosphodiesterase | <enzyme> An enzyme that catalyses the hydrolysis of adenosine 3',5'-cyclic phosphate forming 5'-AMP. A crucial step in the regulation of cellular adenosine 3',5'-cyclic phosphate levels. Inhibited by caffeine. Synonym: cAMP phosphodiesterase. (05 Mar 2000) |
| adenosine 3'-phosphate | 3'-Adenylic acid. See: adenylic acid. (05 Mar 2000) |
| adenosine 3'-phosphate 5'-phosphosulfate | 3'-phosphoadenosine 5'-phosphosulfate;an intermediate in the formation of urinary ethereal sulfates, notable for containing a "high energy" sulfate bond; the 3'-OH of adenosine is replaced by -OPO3H2, the 5'-OH by -OP(O2H)-OSO3H. Synonym: active sulfate. Acronym: PAPS (05 Mar 2000) |
| adenosine 5'-diphosphate | A condensation product of adenosine with pyrophosphoric acid, formed from ATP by the hydrolysis of the terminal phosphate group of the latter compound. Acronym: ADP (05 Mar 2000) |
| adenosine-5'-(n-ethylcarboxamide) | <chemical> A stable adenosine a1 and a2 receptor agonist. Experimentally, it inhibits camp and cgmp phosphodiesterase activity. Pharmacological action: antineoplastic agent, vasodilator agents. (12 Dec 1998) |
| adenosine 5'-phosphate | 5'-Adenylic acid. See: adenylic acid. (05 Mar 2000) |
| adenosine 5'-phosphoramidate hydrolase | <enzyme> Hydrolyzes nucleoside 5'-monophosphoramidates into nucleoside 5'-phosphates and ammonia Registry number: EC 3.9.1.- Synonym: ampn hydrolase, nucleoside monophosphoramidate hydrolase (26 Jun 1999) |
| adenosine 5'-phosphosulfate | An intermediate in the formation of PAPS (active sulfate). Adenosine 5'-phosphosulfate kinase, the enzyme that catalyses the formation of active sulfate from adenosine 5'-phosphosulfate and ATP. Acronym: APS (05 Mar 2000) |
| adenosine 5'-phosphosulfate sulfotransferase | <enzyme> Catalyses transfer of sulfo group of adenylylsulfate to a carrier organic thiol, forming carrier-bound thiosulfate and AMP Registry number: EC 2.8.2.- Synonym: apsstase, aps sulfotransferase, adenylylsulfate sulfotransferase (26 Jun 1999) |
| adenosine 5'-triphosphate | Adenosinepyrophosphate;adenosine with triphosphoric acid esterfied at its 5' position; immediate precursors of adenine nucleotides in RNA. The primary energy currency of a cell. Synonym: adenosine triphosphate. Acronym: ATP (05 Mar 2000) |
| adenosine cyclic phosphate | An activator of phosphorylase kinase and an effector of other enzymes, formed in muscle from ATP by adenylate cyclase and broken down to 5'-AMP by a phosphodiesterase; sometimes referred to as the "second messenger." A related compound (2',3') is also known. Synonym: cyclic adenylic acid, cyclic AMP, cyclic phosphate. Acronym: cAMP (05 Mar 2000) |
| adenosine deaminase | <enzyme> An enzyme that catalyses the hydrolysis of adenosine to inosine with the elimination of ammonia. Since there are wide tissue and species variations in the enzyme, it has been used as a tool in the study of human and animal genetics and in medical diagnosis. Chemical name: Adenosine aminohydrolase Registry number: EC 3.5.4.4 (12 Dec 1998) |
| adenosine diphosphate | <biochemistry> ADP is used as an adenine, a ribose and a diphosphate unit. (06 May 1997) |