cAMP activity and isoproterenol-induced myocardial injury in rats.
Isoproterenol-induced myocardial necrosis (ISO-MN) was obviated by the cardioselective beta-blocker, practolol, suggesting that ISO-MN is caused by specific activation of myocardial beta-adrenergic receptors. Because cAMP is the "second messenger" in such activation, enhanced activity of cAMP should aggravate ISO-MN. Pretreatment of rats with bretylium in various amounts, elicited no ill effects but enhanced the effects of ISO on the cAMP activity and also intensified the ISO-induced structural changes in the myocardium.
D000818:Animals; D001949:Bretylium Compounds / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D006321:Heart / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology*; D008854:Microscopy, Electron; D009206:Myocardium / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D009336:Necrosis; D011217:Practolol / Q000494:pharmacology; D051381:Rats
D001949:Bretylium Compounds; D000242:Cyclic AMP; D007545:Isoproterenol; D011217:Practolol