title: 1 Alpha-25,26-trihydroxyvitamin D3: an in vivo and in vitro metabolite of vitamin D3.
abstract: A new metabolite of vitamin D3 has been isolated from the plasma of vitamin D3 treated cows and has been generated from 25(S),26-dihydroxyvitamin D3 with homogenates of vitamin D deficient chick kidney. This metabolite has been identified as 1,25,26-trihydroxyvitamin D3 by comigration with synthetic 1,25(S),26-trihydroxyvitamin D3 in four chromatographic systems, ultraviolet spectroscopy, mass spectrometry, and high-pressure liquid chromatography and mass spectrometry of derivatives. 1,25(S),26-Trihydroxyvitamin D3 is one-tenth as effective as 1,25-dihydroxyvitamin D3 in binding to the chick intestinal cytosol 1,25-dihydroxyvitamin D receptor. Either 25(S),26-dihydroxyvitamin D3 or 1,25-dihydroxyvitamin  D3 can serve as precursor for in vitro production of 1,25,26-trihydroxyvitamin D3 by chick kidney tissue.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002417:Cattle; D002645:Chickens; D002762:Cholecalciferol / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006887:Hydroxycholecalciferols / Q000096:biosynthesis* / Q000097:blood; D013058:Mass Spectrometry; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006887:Hydroxycholecalciferols; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid; D002762:Cholecalciferol; C030049:1,25,26-trihydroxyvitamin D3