Cells isolated from embryonic intestine synthesize 1,25-dihydroxyvitamin-D3 and 24,25-dihydroxyvitamin-D3 in culture.
Cells isolated from embryonic chick intestine in culture convert 25-hydroxyvitamin-D3 to a number of more polar metabolites. Two of these metabolites have been identified with chemical and chromatographic methods as 24,25-dihydroxyvitamin-D3 (24,25(OH)2D3) and 1,25-dihydroxyvitamin-D3 (1,25(OH)2D3). The enzymes conform to substrate saturation kinetics. The apparent Km for substrate for the synthesis of 1,25(OH)2D3 and 24,25(OH)2D3 is 70 nM and 29 nM, respectively.
D015650:24,25-Dihydroxyvitamin D 3; D000818:Animals; D002117:Calcitriol / Q000096:biosynthesis*; D002478:Cells, Cultured; D002642:Chick Embryo; D002851:Chromatography, High Pressure Liquid; D004100:Dihydroxycholecalciferols / Q000096:biosynthesis*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000196:embryology*; D007700:Kinetics
D004100:Dihydroxycholecalciferols; D015650:24,25-Dihydroxyvitamin D 3; D002117:Calcitriol