PRODUCTION OF ENDOTHELIUM-DERIVED RELAXING FACTOR (EDRF) IS COMPROMISED AFTER ISCHEMIA AND REPERFUSION

Rabbit hind limbs were subjected to 5 hours of ischemia with or withou t 1 hour of in vivo reperfusion, and the response of femoral artery se gments to vasocontrictors and vsodilators was studied in vitro. The ab ility of endothelium-derived relaxing factor (EDRF)-dependent vasodila tors to relax arterial segments was not altered after up to 5 hours of ischemia alone but was significantly decreased after 4 hours, of isch emia if followed by 1 hour of in vivo reperfusion. Thus, we concluded that a specific injury occurs to endothelial cells after ischemia-repe rfusion, which occurs solely during the reperfusion period.