Effect of vitamin D deficiency on D-glucose and citrate transport in rat renal basolateral membrane vesicles.
We had previously reported that feeding rats on Steenbock and Black's rickets-inducing diet markedly influences the metabolic picture of the kidney and the transmembrane transport systems of D-glucose and citrate in renal brush-border membrane vesicles. We have now studied D-glucose and citrate transport into basolateral membrane vesicles prepared from kidney cortex of control and rachitic rats and the effect of 1,25-dihydroxyvitamin D3 on these transport systems was also investigated. D-glucose and citrate uptake, determined in the presence of a Na(+)-gradient, was lowered in rachitic animals and 1,25-dihydroxyvitamin D3 administration proved to be ineffective in restoring normal values. Citrate transport, determined in the presence of a K(+)-gradient, was not influenced by both rickets and 1,25-dihydroxyvitamin D3 supply. The in vitro addition to vesicle preparations of calcium or phosphate or citrate or 1,25-dihydroxyvitamin D3 did not show a selective influence on D-glucose and citrate uptake.
Stio
M
M
Department of Biochemical Sciences, University of Florence, Italy.
Iantomasi
T
T
Marraccini
P
P
Vincenzini
M T
MT
Treves
C
C
D000818:Animals; D001692:Biological Transport; D002117:Calcitriol / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002951:Citrates / Q000378:metabolism*; D019343:Citric Acid; D005947:Glucose / Q000378:metabolism*; D007672:Kidney Cortex / Q000378:metabolism*; D008297:Male; D008871:Microvilli / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012279:Rickets / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism
D002951:Citrates; D019343:Citric Acid; D012964:Sodium; D002117:Calcitriol; D005947:Glucose; D002118:Calcium