1,25-Dihydroxycholecalciferol increases bone resorption in thyroparathyroidectomised mice.
Mice, 1 week old, prelabelled with 45Ca, were either thyroparathyroidectomised or sham-operated; 1 day later half of the mice of each group were injected with 1,25-dihydroxycholecalciferol (5 ng/g), and 20 h later all the mice were killed. Bone resorption in explants was then measured by an in vivo/in vitro technique previously published; compared with untreated mice it was found that 1,25-dihydroxycholecalciferol had increased resorption irrespective of whether the mice had been thyroparathyroidectomised or not. These data suggest that 1,25-dihydroxycholecalciferol is able to increase bone resorption independently of parathyroid hormone.
D000818:Animals; D001862:Bone Resorption / Q000187:drug effects*; D004100:Dihydroxycholecalciferols / Q000494:pharmacology*; D006887:Hydroxycholecalciferols / Q000494:pharmacology*; D051379:Mice; D010280:Parathyroid Glands / Q000601:surgery; D010281:Parathyroid Hormone / Q000502:physiology; D013965:Thyroidectomy
D004100:Dihydroxycholecalciferols; D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone