Continuous infusion of 1,25-dihydroxyvitamin d3 stimulates bone turnover in the normal young mouse.

摘要: The effects of continuous administration 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on mineral and bone metabolism have been examined in the normal mouse. Four doses (0.05-0.25 micrograms/kg/day) 1,25(OH)2D3 were infused continuously for 4 weeks 21-day-old intact animals. Mineral skeletal changes evaluated by analytical methods histomorphometric analysis endosteal formation resorption parameters. All increased fractional osteoclastic surface osteoclast number conjunction with hydroxyproline excretion. induced a dose-dependent elevation calcification rate, reduction mean osteoid seam thickness, shortening mineralization lag time. In addition, there was dose-related increase extent tetracycline double-labeled concurrent rise osteoblastic associated elevated serum alkaline phosphatase levels. Increased appeared to balanced since trabecular volume remained unchanged. Except at highest dose given, calcium phosphate concentrations spite mobilization presumably enhanced intestinal absorption minerals. Urinary cAMP TmP/GFR normal, suggesting that parathormone secretion not altered. results show infusion young mouse produces stimulation rate response resorption. data indicate can regulate turnover as well homeostasis