An Endogenous Ouabain-Like Factor Associated with Hypertensive Pregnant Women*

Abstract

Levels of a ouabain-like factor (OLF) were measured in amniotic fluid from 49 undigitalized third trimester pregnant women by means of its cross-reactivity in a digoxin RIA and its inhibition of ouabain-sensitive [Na,K]ATPase. The results from these 2 assays were significantly correlated (P < 0.05). Of the women included in this study, 25 had blood pressures considered normal for their gestational age, while 24 had developed during their current pregnancy blood pressures judged to be elevated. When levels of OLF in the amniotic fluids from the normotensive and hypertensive pregnant women were compared, significantly higher levels were present in the hypertensive group for both assays (P < 0.002). Further, there was a significant correlation between the diastolic blood pressures of these women at the time of amniocentesis and the amniotic fluid OLF levels determined by either assay (P < 0.002). These results are consistent with OLF having a role in hypertensive complications of pregnancy.