CATECHOLAMINE-INDUCED MYOCARDIAL NECROSIS IN EXPERIMENTAL DIABETES-MELLITUS

Abstract

The pathogenesis of the cardiomyopathy associated with diabetes mellitus is unknown. Among several suggested mechanisms, myocardial necrosis induced by endogenous catecholamines may play a role. The sensitivity of the heart to the effect of varying doses of isoproterenol hydrochloride and norepinephrine bitartrate was examined in diabetic and control rats given streptozotocin. The dose of isoproterenol hydrochloride ranged from 0.008-30 mg/kg body wt. Norepinephrine bitartrate was given in doses from 0.2-1.0 mg/kg body wt. Each dose was given twice, 24 h apart. Animals were killed 48 h after the 1st dose, and their hearts were examined pathologically. Diabetes did not significantly alter the pathological response of the heart to either drug. Evidently diabetic heart is not intrinsically hypersensitive to catecholamines.