The effect of 1,25-vitamin D3 on calbindin-D and calcium-metabolic variables in the rat.
Intraperitoneal injection of 1,25-(OH)2D3 4 micrograms/kg was given to 84 calcium- and vitamin D-repleted Wistar rats and samples of plasma, duodenal mucosa and renal tissue were taken after 0, 3, 6, 12, 24, 48 and 96 hr (n = 12 at each time interval). Plasma-ionized Ca increased after 6 hr, reached a maximum after 24 hr and returned to the initial values after 96 hr. The concentrations of renal calbindin-D28k and intestinal calbindin-D9k did not increase until 48 hr after injection and remained elevated until 96 hr after. Therefore, significantly elevated concentrations of the cytosolic calbindin-D were found at a time with normal values of plasma Ca. The present data suggest that calbindin-D does not alone increase the transcellular Ca transport and, therefore, supports the view that calbindin-Ds may serve as Ca buffer proteins.
Hemmingsen
C
C
Department of Nephrology, Rigshospitalet, University of Copenhagen, Denmark.
Staun
M
M
Olgaard
K
K
D000818:Animals; D064092:Calbindin 1; D064026:Calbindins; D002117:Calcitriol / Q000494:pharmacology*; D002118:Calcium / Q000097:blood*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects*; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*
C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; D064030:S100 Calcium Binding Protein G; C576508:S100g protein, rat; D002117:Calcitriol; D002118:Calcium