RESUMO
Objective To investigate the changes of endothelial function during myocardial ischemia and reperfusion (I/R) injury of rabbits, and the protection of ShenFu injection (SFI) for the injury, as well as the related mechanism. Methods Twenty one Japanese white rabbits were randomly divided into 3 groups (7 each): sham operated group (A), I/R group (B) and SFI-treated I/R group (C). The activity of serum endothelial nitric oxide synthase(eNOS), the concentrations of serum nitric oxide products (NOP) and plasma endothelin (ET) before ligation of coronary artery, 40min after ischemia and 40min after reperfusion were determined. The concentration of total superoxide dismutase (T-SOD) and malonyl-dialdehyde (MDA) in myocardial tissue were determined. Ultrastructure of myocardial cell was observed by electro microscope. Results 1) Serum eNOS and NOP decreased and plasma ET increased ingroup B than that ingroup A after 40min of ischemia (P<0.01), even more significant after 40min of reperfusion. NOP was correlated positively with ETafter 40min of ischemia (P<0. 05) and after 40min of reperfusion ( P<0. 01). In 40min after reperfusion, T-SOD was decreased and MDA was increased ingroup B than that in group A, significantly (P<0. 01). NOP were correlated positively with T-SOD, while were correlated negatively with MDA (P<0.05). ET was correlated positively with MDA, while was correlated negatively with T-SOD (P<0.05). Ultrastructure of myocardial cell changed abnormally. 2) SFI can increase eNOS and NOP after 40min ischemia and 40min reperfusion, and decrease ET after 40min reperfusion, significantly (P<0. 01). SFI can increase T-SOD and decrease MDA significantly (P<0. 01), the abnormality of myocardial cells can be relieved obviously. Conclusion SFI can improve the endothelial function in which free radicals are involved, and prevent myocardial tissue from I/R injury.