title: Effect of papaverine on cyclic AMP, calcium uptake and force of contraction in isolated guinea-pig auricles.
abstract: The effects of papaverine on cyclic AMP (c-AMP), 45 calcium uptake and force of contraction were studied in electrically stimulated left guinea-pig auricles. Papaverine (2 x 10(-6) - 2 x 10(-5)M produced a concentration-dependent positive inotropic effect which was not affected by 10(-7) M propranolol. Papaverine (10(-5)M increased cyclic AMP; this effect developed faster than the increase in twitch tension. Papaverine (10(-5)M) enhanced 45calcium uptake. These results are taken to support the idea of a causative series of interactions between a papaverine induced increase in c-AMP, calcium uptake and force of contraction.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism*; D010208:Papaverine / Q000494:pharmacology*; D013268:Stimulation, Chemical; D013997:Time Factors
chemical_list: D010208:Papaverine; D000242:Cyclic AMP; D002118:Calcium