Effect of myocardial reperfusion on cardiocyte apoptosis and expression of bcl -2,box and caspase -3 in rats with depression

AIM:To explore the effect of ischemia/reperfusion(I/R) on cardiac myocyte apoptosis and the expression of bcl -2,bax and caspase -3 in the rats with depression.METHODS:Thirty-two Wistar rats were randomly divided into 4 groups,including group A:sham operation group;group B:the rats with depression undergoing sham operation; group C:the rats with myocardial I/R operation;group D:the rats with depression undergoing myocardial I/R operation. The rat model of depression was produced by chronic mild unpredictable stress and separation.The behaviors of the rats were detected by open field test and fluid consumption test.The myocardial I/R model was made by ligating the left anterior descending branch of coronary artery in the rats.The apoptotic cardiomyocytes were detected by in situ TdT-mediated dUTP nick end labeling(TUNEL) method,and the expression of bcl -2,bax and caspase -3 was detemined by the methods of immunohistochemistry and reverse transcription polymerase chain reaction(RT-PCR).RESULTS:Compared with group A and group B,the numbers of apoptotic cardiomyocytes in group C and group D were significantly increased(P 0.01),and the expression of bcl -2,bax and caspase-3 in group C and group D was also significantly increased(P 0.01).No significant difference between group A and B was observed.Compared with group C,the number of apoptotic cardiomyocytes in group D was significantly increased(P 0.05 ).The gene expression of bcl-2 in group D was decreased significantly(P 0.05),while the gene expression of bax and caspase-3 in group D was significandy increased (P0.05).CONCLUSION:Myocardial reperfusion increases apoptosis in ischemic cardiomyocytes in the rats with depression. The mechanisms may be associated with up-regulating the gene expression of bax and caspase-3 while downregulating bcl -2 expression.