Abstract:Objective: To investigate the protective effects of ecdysterone(EDS) on the allograft heart transplant model of rats. Methods: Fifty healthy Sprayue-Dawley(SD) rats were divided into donors and recipients randomly. Hearts were harvested and placed heterotopically into allogenic recipients. All animals were divided into three groups: sham-operation group(only opening and closing the abdomen, n=10), EDS group(injected intraperitoneally with 20 mg/(kg·day) of EDS, n = 10), and control group (injected intraperitoneally with normal saline, n = 10). The pathological changes of myocardial tissue were analyzed by light microscopy and transmission electron microscopy and the levels of myocardial enzymes(GOT, LDH, CPK), SOD, ET-1, NO, MDA in serum were measured. Tissue samples underwent the detection of apoptotic cell death by in situ terminal deoxyribonucleotide transferase-mediated dUTP nick end labeling for apoptotic index(AI) and also by immunohistochemistry method to study the expressions of Bcl-2 and Bax. Results: Pathological examination and transmission electron microscope observation showed greater myocardium damage in the control group. EDS group showed a decrease in the amount of myocardial enzymes, MDA, ET-1 and an increase in the levels of SOD, NO, compared to the control group. The AI of EDS group became lower than that of control group, meanwhile the EDS group increased the expression of Bcl-2 and decreased the expression of Bax. Conclusion: EDS has protective effects on heteroptopic heart transplantation, which provides a new idea for myocardial protection in heart transplantation. However, the mechanism of its protective effect needs further research.