Protective Effects Of Prostaglandin E₁ On The Myocardial Injury Induced By Isoproterenol In Rats

Objective:To observe the protective effects of Prostaglandin E₁(PGE₁) processing in advance on the myocardial ischemic injury induced by isoproterenol(ISO) in rats.Methods:Forty-five Wister rats were randomly divided into 3 groups as following(n=15):normal control group,ISO group and PGE₁ group.The rats in normal control group without any treatment.The rats in ISO group were sc ISO(10mg/kg)to prepare the model of acute ischemic myocardium.Rats in PGE₁ group were injected PGE₁(5μg·kg^-1d^-1)by coccygeal vein continuously for 3 days,then gave them identical dose ISO as before.24 hour after the last treatment,recording the changes of ECG and hemodynamics;measuring serum lactic dehydrogenase(LDH),creatin kinase(CK)and plasma endothelin(ET)activity;observing the myocardial pathological changes by electron microscope.Results:Compared with normal control group,serum LDH,CK and plasma ET activity in ISO group were significantly increased(P＜0.01),and myocardial cell were injured seriously.Compared with ISO group,intravenous injection of PGE₁ in advance decreased the elevation of ST-T period induced by ISO remarkably (P＜0.05);enhanced myocardial systolic and diastolic function,improved cardiac function of rats distinctly;reduced serum LDH and CK content(P＜0.01).Also,it inhibited the increase of plasma ET level(P＜0.05)and lightened obviously the reaction of degeneration and necrosis of ischemic myocardium damaged by ISO.Conclusion:PGE₁ lowered the lever of plasma ET of myocardial ischemia rats markedly;protected the vascular endothelium cell and improved its function;inhibited the myocardial injury from ischemia. PGE₁ has preventive and protective effects on myocardial injury induced by ISO in rats.