Altered sensitivity to a novel vasoconstrictor endothelin-1 (1-31) in myometrium and umbilical artery of women with severe preeclampsia.

We have suggested that a novel endothelin-1 with 31 amino acids [ET-1 (1-31)] plays an important role in fetal circulation, owing to a strong contractile activity on the umbilical artery. To clarify the pathophysiological significance of ET-1 (1-31) in the development of severe preeclampsia, its contractile activities on human umbilical arteries and uterine smooth muscle from patients with preeclampsia were studied. The contraction by ET-1 (1-31) was stronger in uterine smooth muscle of the patients with severe preeclampsia than that of normal subjects. On the contrary, the constriction of umbilical artery of the patients with eclampsia was significantly weaker than that of normal pregnant women. The stronger contraction of myometrium by ET-1 (1-31) in patients with severe preeclampsia observed for the first time in the present study suggests that ET-1 (1-31) might be involved in the development of preeclampsia.