[Prevention of disorders in the contractile function of non-ischemic sections of the heart during experimental...

The effect of pretreatment with beta-endorphin on disorders of right-atrial myocardial distensibility and contractility in left-ventricular infarction (by Selye) was examined in Wistar rats. This peptide, administered intravenously (50 micrograms/kg) immediately before the simulation of infarction, was shown to reduce considerably infarction-induced impairment of distensibility and contractility of an isolated right atrium and of its resistance to hypoxia and excessive calcium, and also to increase the survival rate. The results of the study suggest that the protective effect of beta-endorphin is chiefly due to its central action.