ABSTRACT
Objective To investigate the protein expression of Atg7 and Atg12-Atg5 in myocardium of streptozotocin (STZ)diabetic rats.Methods The diabetic model was made in rats by injection of STZ.The rats were divided into control group(NC)and diabetes model group(DM).The left ventricular weight index of rats was detected at the time of 10,20,30,40,60,80,100 d after model initiated.The protein expression of Atg7 and Atg12-Atg5 in myocardium of rats was assayed by western blot.The myocardial ultrastructure and autophagosome were observed by electron microscope. Results Compared with rats in NC group at the same period,the left ventricular weight index in DM group increased since the day of 40th.The protein expression of Atg7 and Atg12-Atg5 in myocardium of diabetic rats increased a little at 20 d(It had not a statistical significance),but reduced significantly at 80 d(P<0.01).The changes in the myocardial ultrastructure and decrease in autophagosome were both obvious in diabetic rats at 80 d.Conclusions With the develop-ment of diabetes mellitus,the autophagy level in myocardium of STZ diabetic rats finally is reduced.