Effects of ghrelin on action potential and transient outward potasiumcurrent in streptozotocin-induced diabetic cardiomyopathy rats / 西安交通大学学报(医学版)

ABSTRACT

Objective To study the effects of ghrelin on action potential (AP) and transient outside K+ current (Ito) in ventricular myocytes of diabetic cardiomyopathy (DCM) rats.Methods A rat model of DCM was established by single intraperitoneal injection of streptozotocin (STZ, 60mg/kg), and whole cell patch-clamp technique was used to record the effects of 10-7mmol/L ghrelin on AP and Ito current density in the DCM rat ventricular myocytes.Results Compared to DCM group, Ghrelin of 10-7mmol/L could significantly prolong APD50 [(12.49±2.32)％;n=7, P=0.037] and APD90 [(26.29±5.13)％;n=7, P=0.006] and decrease Ito current peak value [(23.14±3.07)％;n=9, P=0.021] in DCM rat ventricular myocytes.Conclusion Exogenous ghrelin is involved in the electrophysiological reconstruction of the heart of diabetic rats by decreasing Ito current and prolonging APD in STZ-induced DCM rat ventricular myocytes.