Effects of Pinacidil on Ventricular Repolarization in LQT2 Rabbit Heart / 医学研究杂志

ABSTRACT

Objective To study the effects of Pinacidil on Ventricular Repolarization in LQT2 Rabbit Heart.Methods 30 New Zealand white rabbits weighted from 2.5~3.0 kg were randomly divided into 3 groupsgroup A(control),group B(pinacidil),group C(pinacidil + glibenclamide).Left ventricular endocardium and epicardium MAPs and volume-conducted ECGs in isolated Langendorff-perfused rabbit hearts were recorded simultaneously.To induce bradycardia,the AV nodes of rabbit hearts were damaged.EAD and TdP were induced by means of bradycardia in the presence of high concentration of d-sotalol(10-4M).Results In group B,pinacidil(5?mol/L)shortened the APD90 on endocardium from 445.48?54.31ms to 278.87?44.45ms after administration of pinacidil for 5 minutes(P0.05 vs.group A for all).Conclusion Pinacidil can decrease prolonged action potencial duration and TDR induced by bradycardia and high concentration of d-sotalol in rabbit hearts.Also,pinacidil could abolish the EAD and TdP related to delayed repolarization that may provide a novel and useful intervention in the clinical LQTS patients.