These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Bidirectional sodium fluxes across the placenta of conscious sheep.
    Author: Weedon AP, Stacey TE, Ward RH, Boyd RD.
    Journal: Am J Physiol; 1978 Dec; 235(6):F536-41. PubMed ID: 736137.
    Abstract:
    Conscious pregnant sheep in the last 3 wk of gestation were studied 1--3 days after surgery. Fetal plasma sodium concentration was significantly lower than maternal. A mean electrical potential difference (PD) of 34 +/- 4 (SE) mV (n = 24) was recorded between maternal and fetal intravascular catheters, the mother being positive with reference to fetus. Unidirectional fetomaternal (Jf leads to m) and maternofetal (Jm leads to f) sodium fluxes were determined by application of Fick's principle to uterine and umbilical circulations following injection of 22NaCl or 24NaCl to fetus or mother, respectively. Blood flows were measured by an antipyrine technique. Jm leads to f = 0.142 +/- 0.029 mmol/min (n = 10); Jf leads to m =0.137 +/- 0.015 mmol/min (n = 21). Jm leads to f increased as a linear function of calculated fetal weight. In seven sheep both Jm leads to f and Jf leads to m were measured in a single experiment. The measured ratio Jm leads to f/Jf leads to m was significantly different from the ratio predicted using Ussing's flux ratio equation. There is probably a transplacental sodium pump active in the direction fetus to mother.
    [Abstract] [Full Text] [Related] [New Search]