Abstract: Objective To determine the effect of resveratrol on constrictions of isolated human intrapulmonary arteries and its
mechanisms. Methods Intrapulmonary arteries (1-1.5 mm in diameter) were dissected and cut into rings (1.8-2.0 mm in length)
under microscope, and were then mounted in a Multi Myograph system. The rings were stimulated with 100 nmol/L U46619,
30 nmol/L endothelin-1, or 60 mmol/L KCl to produce sustained contraction of the intrapulmonary arteries, after which resveratrol
was applied cumulatively. Endothelium denudation, L-NAME and indomethecin were used to investigate the effect of
resveratrol on constrictions of the isolated arteries, suing DMSO as the control. Results Resveratrol induced concentration-dependent
relaxations in endothelium-intact rings that contracted in response to stimulations with U46619, ET-1 and KCl, with
pD2 of 3.82±0.20, 3.84±0.57, and 3.68±0.27, Emax of (99.58±0.83)%, 100%, and (99.65±0.98)%, respectively. Treatment of the arterial
rings with the eNOS inhibitor L-NAME, but not with indomethecin or endothelium denudation, obviously affected the relaxant
effects of resveratrol. Conclusion Resveratrol can concentration-dependently produce relaxant effect on human intrapulmonary
arteries independent of the endothelium possibly by promoting synthesis and release of NO.