Investigations of Vascular Responses of Human Umbilical Vessels from Normal and Preeclamptic Pregnancies

Abstract

Objective: We have investigated the isometric contractions produced by vasoactive agents in human umbilical arteries and veins from normal and preeclamptic pregnancies. Methods: Umbilical cords were collected from 70 normotensive and 20 preeclamptic women. Ring segments of umbilical vessels were suspended in organ baths under tension. Cumulative concentration response curves were carried out to 5-hydroxytryptamine (5-HT), prostaglandin F2alpha (PGF2(V) and endothelin 1 (ET-1). Conclusions: There were no differences in the responsiveness of vessels from normal and preeclamptic pregnancies to 5-HT, PGF2α and ET-1, in terms of either EC50 or maximum response. Results: In human umbilical arteries, 5-HT produced EC50 (concentration producing 50% of maximum response: mean and 95% confidence limits) values of 89.1 nM (38.7-204) and 158 nM (75.3-333); PGF2α produced EC50 values of 3.3 μM (1.71-6.37) and 3.94 μM (1.72-9.02); and ET-1 produced EC50 values of 12.1 nM (4.2-35.1) and 24.3 nM (7.71-76.7) in normal and preeclamptic vessels, respectively. In human umbilical veins, 5-HT produced EC50 values of 257 nM (74.1-891) and 154 nM (75.9-316); PGF2, produced EC50 values of 5.86 μM (2.42-14.2) and 6.38 μM (2.48-16.4); and ET-1 produced EC50 values of 14.8 nM (9.8-22.2) and 15.8 nM (7.69-32.7) in normal and preeclamptic vessels, respectively.