Preservation of the vasodilative effect of endothelium-derived relaxing factor in the hind limb of the rat.

Abstract

Using an extracorporeal circulatory system of fresh blood, the vasodilative effect of endothelium-derived relaxing factor (EDRF) secreted from vascular endothelium, stimulated by acetylcholine (ACh), was evaluated. The bioassay cascade technique was applied to elucidate the release of EDRF. Elevated blood pressure of freshly amputated rat hind limbs, created by injection of norepinephrine (NE), decreased by 56% with ACh infusion, suggesting the existence of EDRF in the peripheral vascular system of rat hind limbs. The vasodilative effect of EDRF could be preserved for at least 6 hours when stored at room temperature. The effect of EDRF decreased markedly following storage for more than 9 hours at room temperature and storage for more than 3 hours at 4 degrees C.