title: Characterization of new conjugated metabolites in bile of rats administered 24,25-dihydroxyvitamin D(3) and 25-hydroxyvitamin D(3).
abstract: The characterization of new conjugated vitamin D metabolites in rat bile was performed using HPLC, liquid chromatography/tandem mass spectrometry combined derivatization, and GC-MS. After the administration of 24,25-dihydroxyvitamin D(3) to rats, 23, 25-dihydroxy-24-oxovitamin D(3) 23-glucuronide, 3-epi-24, 25-dihydroxyvitamin D(3) 24-glucuronide, and 24,25-dihydroxyvitamin D(3) 3-sulfate were obtained as new biliary metabolites together with 24,25-dihydroxyvitamin D(3) 3- and 24-glucuronides. The above metabolites, except 24,25-dihydroxyvitamin D(3) 3-glucuronide, were obtained from rats dosed with 25-hydroxyvitamin D(3). 23, 25-Dihydroxyvitamin D(3) 23-glucuronide was also obtained from the bile of rats administered 25-hydroxyvitamin D(3) in addition to its 3-glucuronide, 25-glucuronide, and 3-sulfate. Thus, it was found that 24,25-dihydroxyvitamin D(3) and 25-hydroxyvitamin D(3) were directly conjugated as glucuronide and sulfate, whereas at the C-23 position, they were hydroxylated and then conjugated. Furthermore, we found that the C-3 epimerization acts as one of the important pathways in vitamin D metabolism.
authors.affiliation: Faculty of Pharmaceutical Sciences, Kanazawa University, 13-1 Takara-machi, Kanazawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Higashi
authors.forename: K
authors.initials: K
authors.lastname: Miura
authors.forename: R
authors.initials: R
authors.lastname: Kikuchi
authors.forename: K
authors.initials: K
authors.lastname: Shimada
authors.forename: H
authors.initials: H
authors.lastname: Hiyamizu
authors.forename: H
authors.initials: H
authors.lastname: Ooi
authors.forename: Y
authors.initials: Y
authors.lastname: Iwabuchi
authors.forename: S
authors.initials: S
authors.lastname: Hatakeyama
authors.forename: N
authors.initials: N
authors.lastname: Kubodera
mesh_terms: D015650:24,25-Dihydroxyvitamin D 3 / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001646:Bile / Q000737:chemistry*; D002112:Calcifediol / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D004100:Dihydroxycholecalciferols / Q000737:chemistry / Q000302:isolation & purification; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D020719:Glucuronides / Q000737:chemistry / Q000302:isolation & purification; D008297:Male; D015394:Molecular Structure; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004100:Dihydroxycholecalciferols; D020719:Glucuronides; D015650:24,25-Dihydroxyvitamin D 3; D002112:Calcifediol