Lack of relationship between myocardial cyclic AMP concentrations and inotropic effects of sympathomimetic amines.
1. Sympathomimetic amines which increase the contractility of the isolated heart were tested for effects on cyclic AMP concentrations in rabbit heart slices and on adenyl cyclase activity in rabbit heart homogenate.2. Noradrenaline, as expected, stimulated adenyl cyclase activity and increased cyclic AMP concentrations, but dopamine and phenylephrine were ineffective.3. This result does not support the concept that cyclic AMP plays an essential role in the inotropic effect of sympathomimetic amines.
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism*; D004298:Dopamine / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011817:Rabbits; D013268:Stimulation, Chemical; D013566:Sympathomimetics / Q000494:pharmacology*; D014316:Tritium
D013566:Sympathomimetics; D014316:Tritium; D010656:Phenylephrine; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D004298:Dopamine; D009638:Norepinephrine