[The role of endogenous opioid peptides in the mechanisms of the antiarrhythmic effect of adaptation].

Abstract

A decrease in severity and incidence rate of the epinephrine- or CaCl2-induced arrhythmias was found in the rats adapted to stress. An increase of the beta-endorphin and enkephalin levels was revealed in the brain areas, heart, suprarenal glands and in the blood plasma of such rats. Naloxone eliminated the antiarrhythmic effect of the adaptation, as well as D-kyotorphin. The antiarrhythmic effect seems to result from an increase of the endogenous opioid peptides level.