title: Direct action of 1,25-dihydroxyvitamin D on bone: VDRKO bone shows excessive bone formation in normal mineral condition.
abstract: In the present study, the direct role of Vitamin D in bone metabolism was investigated. Vitamin D has been suggested to be an important hormone for bone metabolism, but there has been little evidence that Vitamin D actively participates in this process. Here, we show the direct action of Vitamin D by transplanting the bone of the Vitamin D receptor null mutant mice (VDR-/-) to the wild-type mouse. This procedure allowed us to investigate the changes in the bone without VDR in the normal humoral environment. Unexpectedly, the volume and the density of the VDR-/- bone transplanted to the wild-type mouse were significantly increased compared with the control (wild-type bone transplanted to the wild-type mouse). We show that Vitamin D has key roles in bone metabolism negatively.
authors.affiliation: Department of Pediatrics, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. hrtanaka@hospital.okayama-u.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Seino
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D016025:Bone Transplantation; D001842:Bone and Bones / Q000187:drug effects*; D002118:Calcium / Q000097:blood; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010758:Phosphorus / Q000097:blood; D018167:Receptors, Calcitriol / Q000235:genetics / Q000502:physiology*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D018167:Receptors, Calcitriol; D014807:Vitamin D; D010758:Phosphorus; C097949:1,25-dihydroxyvitamin D; D000469:Alkaline Phosphatase; D002118:Calcium