[Effects of sulmazole on beating rate and cAMP levels in cultured cardiomyocytes].
The effect of sulmazole (Sul) on beating rate of cultured neonatal rat cardiomyocytes was similar to that of isoproterenol (Iso). They all produced a positive chronotropic action in a dose-dependent manner (Sul 1-100 mumol/L, Iso 1-300 nmol/L). Iso increased intracellular cAMP levels in a dose-dependent manner simultaneously, while Sul did not until toxic concentration (1 mmol/L) was given. With Sul 300 mumol/L the cAMP levels were not elevated significantly even when the positive chronotropic effect was maximal (5 min). The results indicate that cAMP is not important in mediating the positive chronotropic effect of Sul.
Miao
C Y
CY
Department of Pharmacology, Second Military Medical University, Shanghai, China.
Gu
K M
KM
D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D006339:Heart Rate / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology; D009206:Myocardium / Q000166:cytology; D051381:Rats; D011919:Rats, Inbred Strains; D013268:Stimulation, Chemical
D002316:Cardiotonic Agents; D007093:Imidazoles; D000242:Cyclic AMP; C029758:sulmazole; D007545:Isoproterenol