Comparison of Endothelin-1 Concentrations in Normal and Complicated Pregnancies

Endothelin-1 (ET-1) may be important in regulating vascular tone in humans. To understand the role of ET-1 during pregnancy, we measured the concentrations of plasma immunoreactive ET-1 in normal, toxemic (pre-eclamptic or eclamptic), and other complicated pregnancies. There were no significant differences between ET-1 concentrations in normal pregnancy and those in toxemic pregnancy, except in one case with IgA nephropathy and severe toxemia. There also was no significant difference between the ET-1 concentrations in pure toxemia of pregnancy compared with superimposed toxemia of pregnancy. Furthermore, there was no correlation between ET-1 concentrations, blood pressure, or renal function during toxemic pregnancy. Similarly, there were no significant differences between ET-1 plasma levels in normal pregnancies and other complicated pregnancies except for two cases in which much blood was lost due to uterine atony and abruptio placenta. Thus, plasma ET-1 concentrations showed no significant relationship to blood pressure or renal function during normal or toxemic pregnancy, and were not related to the type (pure or superimposed type), grade, or severity of toxemic pregnancy.