[Comparative evaluation of biological activity of 1 alpha,25-dihydroxycholecalciferol and 24,25-dihydroxycholecalciferol in rats].
Deficiency of vitamin D in rats led to impairment of Ca2+ absorption in intestine, hypocalcemia, decrease in specific weight of femur diaphyses, decrease in content of Ca2+ and in the ratio Ca2+/hydroxyproline in diaphyses and epiphyses. These patterns were normalized after daily administration of cholecalciferol (vitamin D3) at a dose of 500 ng (20 IU) into rats within 5 days. I alpha, 25-dihydroxycalciferol at a daily dose of 30 ng stimulated absorption of Ca2+ in intestine, increased the specific weight of diaphyses and content of Ca2+ in diaphysis, but content of Ca2+ in blood and epiphyses was not normalized. Increase in 1,25 (OH)2D3 dose up to 300 ng caused a decrease in the rate of mineralization of diaphyses and epiphyses with simultaneous elevation of the Ca2+ content in blood. 24, 25-dihydroxycalciferol at a dose of 250 ng stimulated effectively both diaphyses and epiphyses mineralization, at the same time the effect was also maintained after 10-fold increase of the dose.
D015650:24,25-Dihydroxyvitamin D 3; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D001693:Biological Transport, Active; D001842:Bone and Bones / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D004100:Dihydroxycholecalciferols / Q000494:pharmacology / Q000502:physiology*; D006909:Hydroxyproline / Q000378:metabolism; D007408:Intestinal Absorption; D010012:Osteogenesis; D010758:Phosphorus / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014808:Vitamin D Deficiency / Q000503:physiopathology*
D004100:Dihydroxycholecalciferols; D010758:Phosphorus; D015650:24,25-Dihydroxyvitamin D 3; D000469:Alkaline Phosphatase; D002117:Calcitriol; D006909:Hydroxyproline; D002118:Calcium
Sravnitel'noe izuchenie biologicheskoĭ aktivnosti 1 alpha,25-dioksikholekal'tsiferola i 24,25-dioksikholekal'tsiferola u krys.