Protective Effects of ATP-sensitive Potassium Channel Opener on Ischemia/Reperfusion Injury in Isolated Rat Hearts

Objective To investigate the Protective effects of Pinacidil,an ATP sensitive potas sium channel opener on ischemia/reperfusion injury in isolated rat hearts. Methods On modified Langendorff apparatus,twenty isolated hearts of rats were divided into two groups randomly:St.Thomas solution(control group) and St. Thomas solution plus Pinacidil(Pinacidil group),all subjected to 90 minutes of ischemia and 15 minutes of reperfusion.The preischemia and postischemia myocardial function were assessed by the percentage recovery of left ventricular systolic pressure (LVSP),left ventricle end diastolic pressure (LVEDP),the highest rate of rise / decrease of left ventricular pressure (±dp/dtmax),heart rate (HR),RT PCR was used to measure the variety of NOS mRNA and the density of PCR products was determined by image analysis.Results Postischemia recovery of LVSP,LVEDP,±dp/dtmax,HR were significantly better in Pinacidil group than that in the control group,after reperfusion eNOS mRNA was higher significantly and iNOS mRNA was lower in Pinacidil group than that in the control group. Conclusion As a new and effective compostion,Pinacidil can improve the myocardial protective effects of St.Thomas solution significantly for rat hearts.