Nicodil preconditioning improves cardiac function in rat models of diabeties complicated with coronary heart disease

Objective To identify the impacts of nicorandil (Nic) on cardiac function of rats with diabetes mellitus and coronary heart disease (DM/CHD) and to explore the potential mechanism. Methods Rats were divided into: control group, DM/CHD group, DM/CHD+Nic group and DM/CHD+Nic+shTRPV1 group. The cardiac function parameters were detected by electrocardiogram. Blood was collected for biochemical index detection. Cardiac histo-pathological changes, collagen deposition and apoptosis were determined by HE, Masson trichrome and TUNEL staining microcopy respectively. The protein expression was analyzed by Western blot. Results In comparation to control group, the cardiomyocyte diameter and collagen accumulation were increased (P＜0.05). Apoptotic cells and the expression of Bax and cleaved caspase-3 were increased (P＜0.05),expression of Bcl-2, TRPV1, p-PI3K and p-Akt was decreased. Compared with DM/CHD group, myocardial cell diameter and collagen accumulation were reduced (P＜0.05). Apoptotic cells and the level of Bax and cleaved caspase-3 were reduced (P＜0.05).The expression of Bcl-2, TRPV1, p-PI3K and p-Akt was enhanced (P＜0.05). Compared with DM/CHD+Nic group, myocardial cell diameter and collagen accumulation were increased (P＜0.05). Apoptotic cells and the expression of Bax and cleaved caspase-3 were up-regulated (P＜0.05).The expression of Bcl-2, TRPV1, p-PI3K and p-Akt was down-regulated. Conclusions Nic improves cardiac function in DM/CHD rats with potential mechanism of regulating TRPV1-PI3K/Akt signaling pathway.