Comparison of the effects of vitamin D3, dihydrotachysterol, and parathormone on calcium kinetics in the rat.
Rats were treated with 100 I.U. (= 2.5 mcg) Vit. D3/day during 14 days and submitted to a radio-Calcium assay of Calcium kinetics. The results were compared with those obtained in weight-matched pair-fed controls, and with those obtained in former experiments applying dihydrotachysterol and parathormone. Vit. D3, which is transformed to a hormone, increased the fast exchange compartment, the exchange rate between the compartments, the endogenous fecal Calcium excretion rate, and the bone uptake and release rates. These findings indicate that the Vit. D-hormone is more similar in its action to the other hormone, parathormone, than to its close chemical relative dihydrotachysterol.
D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000032:analysis / Q000378:metabolism*; D002132:Calcium Radioisotopes; D002762:Cholecalciferol / Q000494:pharmacology*; D004097:Dihydrotachysterol / Q000494:pharmacology*; D005243:Feces / Q000032:analysis; D005260:Female; D007700:Kinetics; D010281:Parathyroid Hormone / Q000494:pharmacology*; D051381:Rats
D002132:Calcium Radioisotopes; D010281:Parathyroid Hormone; D002762:Cholecalciferol; D004097:Dihydrotachysterol; D002118:Calcium