The effect of inosine (200 mg/kg ip) injected 30 and 10 min before adrenaline (AD) administration to rats was studied. AD in the single dose (2 mg/kg sc) evoked heart necrosis evidenced by plasma activities of CPK-MB, CPK, blood lactates concentrations and histopathological examination. Inosine pretreatment caused less pronounced enhancement of enzyme activities and lactate concentrations in both experimental groups. Histopathological examination confirmed the protective effect of inosine on adrenaline-induced myocardial necrosis.