Abstract
OBJECTIVE: Elevated blood levels of endogenous digitalis-like factors (EDLF) may decrease erythrocyte sodium pump activity in preeclampsia. As the highest EDLF levels might be expected in severe preeclampsia, we investigated sodium pump activity in that group of patients. STUDY DESIGN: Erythrocyte sodium pump activity was determined by (86)Rubidium uptake (in nM per hour per 10(6) cells) in women with severe preeclampsia and those with normal pregnancies, matched for gestational age, and in healthy nonpregnant women (n=12 in each group). Differences between groups were analyzed by a two-sided Student t-test. RESULT: Sodium pump activity was significantly increased in normotensive pregnancies as compared with normotensive non-pregnant women (81.4+/-8.4 vs 61.1+/-7.4, mean+/-s.d., p<0.05), and was decreased 43% in severe preeclamptic pregnancies as compared with normotensive pregnancies (46.4+/-14.1 vs 81.4+/-8.4, p<0.05). CONCLUSION: Severe preeclampsia is associated with significantly lower erythrocyte sodium pump activity than normotensive pregnancy. These data suggest that plasma levels of a biologically active EDLF are elevated in patients with severe preeclampsia.