title: Chronotropic and cyclic adenosine monophosphate response of fetal rat heart in organ culture to isoproterenol, quinidine, and a dysrhythmogenic agent.
abstract: The fetal rat heart in organ culture was used to investigate rate chanes by various cardioactive agents. Concomitantly, the effect of these pharmacologically induced rate changes on steady-state cyclic adenosine monophosphate levels was determined. Isoproterenol increased the fetal rat heart rate and cyclic adenosine monophosphate in a concentration-related fashion. Quinidine produced a concentration-related decrease in heart rate and no change in cyclic adenosine monophosphate level. The dysrhythmogenic agent produced concentration-related negative chronotropism in the fetal rat heart preparation and significant elevations in cyclic adenosine monophosphate at concentrations without chronotropic action. No correlation between chronotropic effect of a drug and cyclic adenosine monophosphate levels was observed.
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced*; D000242:Cyclic AMP / Q000378:metabolism*; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology*; D009206:Myocardium / Q000378:metabolism*; D009924:Organ Culture Techniques; D011247:Pregnancy; D011802:Quinidine / Q000494:pharmacology*; D051381:Rats; D013843:Thiazines / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D013843:Thiazines; D000242:Cyclic AMP; D011802:Quinidine; D007545:Isoproterenol