About this Biochemistry, Genetics and Molecular Biology article

In vivo administration of 1,25‐dihydroxyvitamin D~3~ suppresses the expression of RANKL mRNA in bone of thyroparathyroidectomized rats constantly infused with PTH by Yutaka Ueno; Toshimasa Shinki; Yumiko Nagai; Hisashi Murayama; Katsuyuki Fujii; Tatsuo Suda is a Biochemistry, Genetics and Molecular Biology article available to read on EtoBox.

## Abstract It is known that pharmacological or toxic doses of vitamin D induce bone resorption both in vivo and in vitro, whereas physiological doses of the vitamin have a protective effect on bone in vivo. To investigate the discrepancies of the dose‐dependent effect of vitamin D on bone resorption, we examined the in vivo effect of 1,25‐dihydroxyvitamin D~3~ [1,25(OH)~2~D~3~] on the expression of the receptor activator of nuclear factor‐κB (NF‐κB) ligand (RANKL) and osteoprotegerin (OPG) mRNAs in bone of thyroparathyroidectomized (TPTX) rats infused with or without parathyroid hormone (PTH). Continuous infusion of 50 ng/h of PTH greatly increased the expression of RANKL mRNA in bone of TPTX rats. Expression of OPG mRNA was not altered by PTH infusion. When graded doses of 1,25(OH)~2~D~3~ was daily administered orally for 14 days to normocalcemic TPTX rats constantly infused with PTH, 0.01 and 0.1 μg/kg of 1,25(OH)~2~D~3~ inhibited the PTH‐induced RANKL mRNA expression, but 0.5 μg/kg of the vitamin did not inhibit it. Regulator of G protein signaling‐2 (RGS‐2) gene expression was suppressed by 1,25(OH)~2~D~3~ dose‐dependently, but PTH/PTHrP receptor mRNA expression was not altere

Author

Yutaka Ueno; Toshimasa Shinki; Yumiko Nagai; Hisashi Murayama; Katsuyuki Fujii; Tatsuo Suda

Publisher

John Wiley and Sons; Wiley (John Wiley & Sons); John Wiley & Sons Inc.; Wiley (ISSN 0730-2312)

Published

2003

Language

EN

Field

Biochemistry, Genetics and Molecular Biology (Life Sciences)