A Study Of The Expression Of NO, NOS In Heart Tissues During The Course Of Ischemic-Reperfusion After Orthotopic Heart Transplantation In Pig

Objects To investigate the content of N(K NOS in heart tissues during the course of ischemic-reperfusion after pigs' orthotopic heart transplantation, as well as to determine the expression of eNOS, iNOS and the relation between N0, NOS and ischemic-repefusion injury. Methods The animal models of orthotopic heart transplantation in pigs were successfully established. Hearts of donors were preserved 4 hours in cold storage (Thomas liquid, 4C) before transplanted to receptor. Two hours after transplantation, the grafts were collected to be detected. The content of NOX NOS in heart tissue was measured by histochemical method; The expression of eNOS% iNOS was detected by immunohistochemistry and quantitiative measurement was done with multimedia pathology imaging analysis system; Apoptosis of myocardium was detected as the index of ischemic-reperfusion injury by using in situ terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and apoptotic index (AI) was analyzed. Normal heart tissue and ischemic heart were used for compare. Results Ischemic-reperfusion injury sharply occurred in graft two hours after transplantation. The AI of graft increased significantly compared with normal heart and ischemic heart. What's more there was also no difference between normal heart and ischemic hearts; The content of NO, NOS in graft decreased. However no difference was detected between normalheart and ischemic heart; The expression of eNOS sharply decreased in graft, while the expression of iNOS has no change. It was the expression of eNOS in myocardium that has changed sharply but not in vascular endothelial cells; The content of NCK NOS and the expression of eNOS had negative correlation with myocardial apoptosis. There was no correlation between iNOS and cell apoptosis. Conclusions 1 The main injury of early ischemic-reperfusion after heart transplantation in pig was myocardium cell apoptosis. 2 Decreased production of endogenous NO,NOS has contributed to the ischemic-reperfusion injury after orthotopic heart transplantation in pig. 3 eNOS played an important role in myocardium reperfusion injury, while iNOS had no effect in it. Expression of eNOS in myocardium cell had more sharply change than that of myocardium vascular endothelial cell during reperfusion injury. 4 Anti-apoptosis perhaps was the mechanism of the effect of NO, NOS on reperfusion injury after heart transplantation.Postgraduate-student Cui Jing ( Pathology ) Directed by- Prof Yu Jian Xian...