title: [D-glucose reabsorption activity of fetal kidney (by using brush border membrane vesicles of proximal tubule)].
abstract: 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.
mesh_terms: D000042:Absorption; D001692:Biological Transport; D005325:Fetal Organ Maturity; D005865:Gestational Age; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007687:Kidney Tubules, Proximal / Q000196:embryology* / Q000378:metabolism; D008564:Membrane Potentials; D008871:Microvilli / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
chemical_list: D012964:Sodium; D005947:Glucose