Effect of vasoactive intestinal polypeptide on uterine blood flow in pregnant ewes

摘要: Abstract Vasoactive intestinal polypeptide has been localized in the uterine vasculature, smooth muscle and placenta of several species. is a potent vasodilator nonpregnant sheep also abolishes spontaneous contractile activity, but effects this on vasculature pregnant animal currently unknown. The present experiments were performed seven late-term which chronically catheterized to evaluate vascular vasoactive polypeptide. An intra-arterial catheter was placed branch main artery allow administration directly into vasculature. Uterine blood flow continuously monitored via an electromagnetic transducer both arteries. infused at rate 1 30 μg/min produced dose-related reductions (33% ± 9% μg/min). This decrease due reduction systemic arterial pressure, since calculated resistance that received did not change significantly. In addition, contralateral receive direct infusions showed identical changes. These data suggest produces peripheral vasodilation doses have very little effect locally. can be interpreted mean either high local endogenous production prevents exogenously administered from exerting its effects, or weak prognant ewes. clarification these possibilities will require further experimentation.