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Updated: Aug 2, 2026
The 4-vessel Sampling Approach to Integrative Studies of Human Placental Physiology In Vivo
Published on: August 2, 2017
Effects of ouabain on the isolated human uteroplacental vasculature
M Glavind-Kristensen1, O B Petersen, A Forman
1Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus N, Denmark.
Objective:
We sought to describe the effects of ouabain on the human uteroplacental vasculature.
Study Design:
Stem villous vessels and intramyometrial arteries isolated from placental and myometrial biopsy specimens at term were mounted in organ baths. Moreover, isolated human placental cotyledons were perfused.
Results:
Contractions induced by the thromboxane A2 analog U46619 were unaffected by pretreatment with ouabain 10(-10) to 10(-6) mol/L. In fetal vessels nitric oxide (10(-8) to 3 x 10(-5) mol/L) induced relaxation of vascular tonus induced by U46619 and potassium. This relaxation was inhibited by pretreatment with ouabain 10(-7) to 10(-6) mol/L. These associations were unaffected by removal of the endothelium. In maternal arteries ouabain (10(-6) mol/L) failed to significantly affect nitric oxide-induced relaxation. Ouabain (10(-9) mol/L) significantly affected pressure-flow relationships in perfused cotyledons.
Conclusions:
Ouabain impairs nitric oxide-induced relaxation of human stem villous arteries and veins, which may explain the changes induced by therapeutically relevant concentrations of the drug on pressure-flow relationships in the perfused cotyledon. Thus treatment with cardiac glycosides in pregnancy may impair uteroplacental blood flow.
