1994 Volume 17 Issue 10 Pages 1341-1344
Effects of diazoxide on norepinephrine-induced vasocontraction in vitro and global ischemia-induced lactate accumulation in the myocardial tissue in vivo were studied in rats. Diazoxide produced relaxation of the isolated rat aorta contracted by norepinephrine in a dose dependent manner. The relaxation of the aorta was associated with reduction of intracellular Ca2+ concentration. This reduction may be due either to activation of KATP channels or Na+-K+ ATPase, or to both. Global ischemia induced by aorta constriction for 30 min in vivo increased the myocardial tissue level of lactate. Pretreatment with diazoxide (10 mg·kg-1, i.v.) significantly attenuated the accumulation of lactate due to global ischemia. The present study suggests that diazoxide reduces ischemic influence on the myocardium partly through its vasodilatory action.