UNLABELLEDOBJECTIVE To investigate the effect of Guanxinkang (GXK) on ATP-sensitive potassium channel in myocardial cells of rat with ischemic/reperfusion injury and its possible mechanism for cardiac vascular protection and anti-myocardial ischemia.

METHODSWistar rats were established into I/R injured models by 10 min perfusion--30 min no-flow ischemia--45 min reperfusion, and divided into 5 groups: the I/R model group and 4 treatment groups treated respectively with glibenclamide, pinacidil, GXK and GXK+glibenclamide. Rats' heart were isolated for detecting Ca(2+)-Mg(2+)-ATPase, Na(+)-K(+)-ATPase activity in myocardial cells, and the changes of current in ATP-sensive potassium channel (K(ATP)) was recorded by whole patch clamp technique. Data were controlled by those taken from normal rats in a control group.

RESULTSK(ATP) in the GXK treated group were higher than that in the I/R model group; and similar to that in the pinacidil treated group (P > 0.05). As compared with the model group, activities of Ca(2+)-Mg(2+)-ATPase and Na(+)-K(+)-ATPase in the GXK treated group were increased significantly (P < 0.05).

CONCLUSIONGXK shows definite intervention effect on myocardial I/R injury; which is possibly by way of furthering the opening of K(ATP) channel, decreasing Ca2+ influx, and inhibiting Ca2+ overload.