Na+-independent D-glucose transport in rabbit renal basolateral membranes

Journal Article · Sun May 01 04:00:00 EDT 1988 · Am. J. Physiol.; (United States)

OSTI ID:7152547

Cheung, P T; Hammerman, M R

To define the mechanism by which glucose is transported across the basolateral membrane of the renal proximal tubular cell, we measured D-(14C)glucose uptake in basolateral membrane vesicles from rabbit kidney. Na+-dependent D-glucose transport, demonstrable in brush-border vesicles, could not be demonstrated in basolateral membrane vesicles. In the absence of Na+, the uptake of D-(14C)glucose in basolateral vesicles was more rapid than that of L-(3H)glucose over a concentration range of 1-50 mM. Subtraction of the latter from the former uptakes revealed a saturable process with apparent Km of 9.9 mM and Vmax of 0.80 nmol.mg protein-1.s-1. To characterize the transport component of D-glucose uptake in basolateral vesicles, we measured trans stimulation of 2 mM D-(14C)glucose entry in the absence of Na+. Trans stimulation could be effected by preloading basolateral vesicles with D-glucose, 2-deoxy-D-glucose, or 3-O-methyl-D-glucose, but not with L-glucose or alpha-methyl-D-glucoside. Trans-stimulated D-(14C)glucose uptake was inhibited by 0.1 mM phloretin or cytochalasin B but not phlorizin. In contrast, Na+-dependent D-(14C)glucose transport in brush-border vesicles was inhibited by phlorizin but not phloretin or cytochalasin B. Our findings are consistent with the presence of a Na+-independent D-glucose transporter in the proximal tubular basolateral membrane with characteristics similar to those of transporters present in nonepithelial cells.

• Research Organization: Washington Univ. School of Medicine, St. Louis, MO (USA)
• OSTI ID: 7152547
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 254; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ALKALI METAL COMPOUNDS
ANIMALS
BODY
CARBOHYDRATES
CELL CONSTITUENTS
CELL MEMBRANES
GLUCOSE
HEXOSES
ISOTOPE APPLICATIONS
KIDNEYS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANS
RABBITS
SACCHARIDES
SODIUM COMPOUNDS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES