D-glucose reabsorption activity of fetal kidney (by using brush border membrane vesicles of proximal tubule)
Iioka, H.; Moriyama, I.; Itoh, K.; Hino, K.; Okamura, Y.; Itani, Y.; Kato, Y.; Ibaragi, T.; Ichijo, M.
Nihon Sanka Fujinka Gakkai Zasshi 39(7): 1037-1041
1987
ISSN/ISBN: 0300-9165 PMID: 3611877 Document Number: 294387
By using brush border membrane vesicles prepared from human mid gestational fetal kidney (cortex), the D-glucose transport mechanism and its developmental pattern was studied by the rapid filtration technique. 1. The transport of D-glucose into brush border membrane vesicles prepared from fetal kidney (18 gestational weeks) did not show a great degree of Na+ gradient (extravesicular greater than intravesicular) dependence. 2. The transport of D-glucose into brush border membrane vesicles prepared from fetal kidney (22 gestational weeks) depended on Na+ gradient. This Na+ dependent D-glucose transport showed overshoot and markedly increased when the intravesicular space was rendered electrically more negative with a membrane potential induced by highly permeant anions or by the K+ diffusion membrane potential via valinomycin. These results indicated that the Na+ dependent active D-glucose reabsorption system in the proximal tubules of kidney might be formed between 18 and 22 gestational weeks and the D-glucose reabsorption mechanism of kidney at 22 gestational weeks was Na+ cotransport dependent on membrane potential as in adult ones.