[Effects of extracts of Ginkgo biloba leaves on apelin concentration and expressions in plasma and myocardium of rats with myocardial ischemia injury].

Objective: To investigate the changes of apelin in plasma and myocardium of model rats and the protective mechanisms of Extracts of Ginkgo biloba leaves (EGb) on myocardial ischemia injury induced by isoproterenol.

Methods: The model of myocardial ischemia injury was induced by subcutaneous injection of high dose isoproterenol. ELISA (enzyme linked immunosorbent assay) was used to measure the apelin concentration in plasma and myocardium. Semi-Quantitative RT-PCR was used to measure the apelin mRNA level in myocardium. The pathomorphology changes of myocardium was observed with light microscope. EGb was administered for 7 weeks.

Results: Compared with the normal control group, the apelin concentration in plasma and myocardium and the apelin mRNA level in myocardium significantly decreased in the model group (P < 0.01). Compared with the model group, the apelin concentration in plasma and myocardium and the apelin mRNA level in myocardium obviously increased in the EGb group (P < 0.01). Meanwhile, the NO content in serum also obviously increased and the pathological damage of myocardium was obviously improved.

Conclusion: The protective mechanisms of EGb on myocardial ischemia injury may be related to the elevation of apelin contents and apelin mRNA level.