Late Reperfusion On Cardiocyte Apoptosis And Expression Of Apoptotic Gene After Acute Myocardial Infarction In Dogs

OBJECTIVE To investigate the effect of late reperfusion of infarct-related artery on cardiocyte apoptosis and expression of Bcl-2 , Bax protein and mRN A in the risk area of acute myocardial infarctin in dogs. METHODS The experiment dogs were divided into three groups: sham operation group, acute myocardial infarction (AMI)group, and late reperfusion (LR) group. Apart from sham operation group, the other two groups dogskin plasterwere subjected to left anterior descending branch of coronary artery ligation, acute myocardial infarction group was only subjected to ligation for 12 hour, late reperfusion group was subjected to ligation for 6 hour following by 6 hour of reperfusion. The cardiocyte apoptosis was measured by TUNEL assay. Immunohistochemistry and RT-PCR were used to detected the expression of Bcl-2 , Bax protein and mRNA. RESULTS The number of apoptotic cardiocytes in late reperfusion group was much less than acute myocardial infarction group (P<0.05) , but significantily more than sham operation group (P<0.01) .The expression of Bcl-2 protein was enhanced slightly in late reperfusion group to compared with acute myocardial infarction group ,but the difference between the two groups was not significant (P>0.05) ,althought it was much more in the two groups than in sham operation group (P<0.01). The expression of Bax protein of late reperfusion group was much higher than sham operation group (P<0.01), and lower than acute myocardial infarction group (P<0.05) .There was no significant differences of the expression of Bcl-2 gene mRNA between acute myocardial infarction group and late reperfusion group (P>0.05) . The expression of Bax gene mRNA in acute myocardial infarction group was much higher than late reperfusion group (P<0.05) CONCLUSION: Late...