The Relative Contribution of NO and EDHF to Acetylcholine-Induced Relaxation in Femoral Artery Rings from Newborn and 2 week old Piglets ♦ 350

Abstract

In the pulmonary and mesenteric circulation, NO is known to be an important vasodilator during the period of postnatal transitional circulation. Little is known about the contribution of endothelium-derived hyperpolarizing factor(EDHF). We previously demonstrated that the NOS-inhibitor L-NMMA had little effect on ACh-mediated relaxation in femoral artery rings from newborn piglets, whereas it significantly inhibited relaxation in rings from 2 week old piglets. We therefore hypothesized that EDHF is more important than NO in mediating ACh-induced relaxation in newborn arteries, and that the relative importance of NO increases with age.