The results of this study showed that after incubation of APN, endothelium-dependent vasorelaxation in the aorta was improved; serum ET-1 and the elevated levels of ICAM-1 and VCAM-1 were obviously reduced after T2DM rats with MI/R, suggesting that APN played a role in relieving coronary NR effect by protecting endothelial cells and improving the function of microcirculation. This evidence concerns the gene EDN1 and type 2 diabetes mellitus.