Women with preeclampsia have higher plasma endothelin levels than women with normal pregnancies.

Endothelin, a newly discovered endothelium-derived peptide, has potent vasoactive properties in vivo and in vitro. The actions of endothelin in clinical conditions of hypertension have not yet been defined. This study examined the possible role of endothelin in the vasospasm and hypertension associated with a well-defined syndrome of gestational hypertension, preeclampsia. Our results indicate that the concentration of immunoreactive endothelin is elevated significantly in plasma obtained from women with preeclampsia and rapidly returns to a normal pregnancy value within 48 hours of delivery, as predicted by the prompt clinical resolution of this disorder. The findings suggest that endothelin may contribute to the vasospasm associated with this syndrome and lend further support to the involvement of endothelial cells in the pathophysiology of preeclampsia.