Abnormal membrane cation transport in pregnancy-induced hypertension.
An abnormality of sodium handling has been suggested as one of the mechanisms responsible for the development of pregnancy-induced hypertension. We analysed the plasma and urinary concentrations, and the intraerythrocyte activities of Na and K, and the RBC membrane Na+/K+-ATPase activity of 77 hypertensive and 133 normal pregnant women. Umbilical cord blood of infants from 21 hypertensive and 28 control women was studied. The Na+/K+-ATPase activity was determined by measuring the inorganic phosphate released by incubation in a reaction medium in the presence and absence of K ions or ouabain. The intra-erythrocyte sodium and potassium activities were measured by ion-selective electrode analysis of the haemolysates, after washing the RBCs in 110 mmol/l MgCl2. We found a significant increase in intracellular sodium and a reduction in Na+/K+-ATPase activity in the hypertensive women in comparison with the control subjects during pregnancy. No difference was observed in early puerperium. Cord blood from infants of pregnancy-induced hypertensive women showed an increase in intracellular Na+ activity and a decrease in the erythrocyte membrane Na+/K+-ATPase activity in comparison with cord blood samples from control subjects. The observed abnormalities in the plasma membrane sodium transport may play a major role in the pathophysiology of pregnancy-induced hypertension.
Testa
I
I
Department of Internal Medicine, University of Ancona School of Medicine, Italy.
Rabini
R A
RA
Danieli
G
G
Tranquilli
A L
AL
Cester
N
N
Romanini
C
C
Bertoli
E
E
Mazzanti
L
L
D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D006973:Hypertension / Q000201:enzymology / Q000378:metabolism* / Q000503:physiopathology; D011188:Potassium / Q000378:metabolism; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000201:enzymology / Q000378:metabolism* / Q000503:physiopathology; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium