Alterations in red cell cation transport in hypertensive disorders of pregnancy.

The results of a cross-sectional study of alterations in red cell Na-Li countertransport in hypertensive disorders of pregnancy indicated that the mean value of Na-Li countertransport increased with gestational age in pregnant normotensives but not in pregnant chronic hypertensives. In addition the mean value was significantly higher in pregnancy-induced hypertensives than in pregnant normotensives. Moreover the mean value falls to a level observed in non-pregnant normotensives in the late post-partum period and no difference was observed between women with normal blood pressure and chronic hypertension. In a prospective study of 62 pregnant normotensives, Na-Li countertransport increased and the Na-K cotransport decreased throughout their pregnancy. Finally, increased amounts of endogenous digoxin-like substance can be detected in the sera from some pre-term infants.