The Effect of Endothelium Derived Relaxing Factor on the Venous Distensibility and the Capillary Filtration in Human Forearm

Abstract

We conducted a present study to clarify the influence of endothelium derived relaxing factor (EDRF) on human venous vasculature. Forearm volume and transmural venous pressure are continuously monitored using water plethysmogram method. With stepwise increase in forearm transmural venous pressure, pressure-volume curve was compared between before and after l-NMMA infusion into forearm. Forearm venous distensibility was significantly decreased. On the other hand, the rate of continuous increase in forearm volume during constant transmural venous, which represents the rate of extravasation from the forearm vasculature, was not significantly influenced by 1-NMMA infusion. Thus, the continuous effect of EDRF on the relaxation is suggested, while there was no evidence for the effect of EDRF on transmural exudation in human forearm.