title: Low levels of intestinal calbindin-D28K in X-linked hypophosphatemic mice.
abstract: Using our radioimmunoassay for chick intestinal calbindin-D28K, a protein homologous to that in the chick intestine on the basis of immuno-crossreactivity, molecular weight and charge properties was identified in mouse intestinal mucosa. No such protein, however, was found in the kidney, cerebellum, cerebrum, liver or myocardium of the mice. In X-linked hypophosphatemic mice (Hyp mice) maintained on a standard diet containing vitamin D, the basal level of intestinal calbindin-D28K was much lower (average 65.13 +/- 7.39%) than that in breeding pairs of normal mice maintained under the same conditions. Although the mean intestinal level of calbindin-D28K was as low as 118.23 +/- 20.08 (SD) ng/mg protein in vitamin D-deficient mice (-D), the level of this protein was markedly increased to the control level (198.68 +/- 9.98 vs. 198.49 +/- 14.29 ng/mg protein of control) (P less than 0.001) in response to the administration of vitamin D3 (1000 I.U. s.c. for 10 days) (+D). These results indicate that calbindin-D28K, biochemically indistinguishable from the chick intestinal calbindin-D28K, is present in the mouse intestine, and that the lower amount of this protein in the Hyp mouse intestine may, at least in part, be responsible for the resistance to the effects of vitamin D.
authors.affiliation: Department of Medicine, Kobe University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tohmon
authors.forename: M
authors.initials: M
authors.lastname: Fukase
authors.forename: T
authors.initials: T
authors.lastname: Fujita
mesh_terms: D000818:Animals; D064092:Calbindin 1; D064026:Calbindins; D005260:Female; D008040:Genetic Linkage; D007015:Hypophosphatemia, Familial / Q000235:genetics* / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000002:abnormalities / Q000032:analysis*; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains / Q000378:metabolism*; D011863:Radioimmunoassay; D064030:S100 Calcium Binding Protein G / Q000032:analysis*; D014807:Vitamin D / Q000378:metabolism / Q000494:pharmacology; D014960:X Chromosome
chemical_list: C576499:Calb1 protein, mouse; D064092:Calbindin 1; D064026:Calbindins; D064030:S100 Calcium Binding Protein G; D014807:Vitamin D