title: Effect of changes in dietary sodium on active electrolyte transport by erythrocytes at different stages of human pregnancy.
abstract: 1. Active electrolyte transport was examined in erythrocytes from women in the second and third trimesters of pregnancy and post partum, and compared with that in ovulating women. 2. There was a significant reduction in intracellular sodium ([Na]i) and increase in intracellular potassium ([K]i) in pregnancy with a return towards normal values in the post-partum period. 3. Maximum specific ouabain binding [number of Na+,K+-adenosine triphosphatase (Na+, K+-ATPase) units] was increased by 70% in pregnancy and returned slowly towards normal values post partum. 4. Na+,K+-ATPase activity as determined by ouabain-sensitive 86Rb influx in artificial media was also increased in pregnancy by 13%. It returned towards normal post partum. 5. The increases in Na+,K+-ATPase in pregnancy were not closely related to the concomitant increases in aldosterone or cholesterol nor to reticulocytosis and were not affected by 7 days of high (greater than 250 mmol/day) or low (less than 50 mmol/day) sodium intake.
authors.affiliation: Department of Renal Medicine, Royal North Shore Hospital, St Leonards, N.S.W., Australia.
authors.forename: E D
authors.initials: ED
authors.lastname: Gallery
authors.forename: J
authors.initials: J
authors.lastname: Rowe
authors.forename: M A
authors.initials: MA
authors.lastname: Brown
authors.forename: M
authors.initials: M
authors.lastname: Ross
mesh_terms: D001693:Biological Transport, Active / Q000187:drug effects; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D010042:Ouabain / Q000494:pharmacology; D049590:Postpartum Period / Q000097:blood; D011188:Potassium / Q000097:blood*; D011247:Pregnancy / Q000097:blood*; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D012964:Sodium / Q000097:blood*; D012982:Sodium, Dietary / Q000008:administration & dosage*; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood
chemical_list: D012982:Sodium, Dietary; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium