title: Stable isotope methodology for kinetic studies of interconversion of cortisol and cortisone in a human subject.
abstract: Oral administration of 5 mg each of deuterium-labeled cortisol ([1,1,19,19,19-2H5]cortisol, cortisol-d5) and cortisone-d5 ([1,1,19,19,19-2H5]cortisone) to a human subject on two different occasions four weeks apart provided a useful means of characterizing the kinetics of the interconversion of cortisol and cortisone. From the data on plasma concentration measurements of cortisol-d5, cortisone-d5, cortisone-5, endogenous cortisol and endogenous cortisone by gas chromatography-mass spectrometry, it was demonstrated that (1) the plasma concentration ratio of cortisone-d5 to cortisol-d5 approached a plateau 4-5 h following either the cortisol-d5 or cortisone-d5 administration and the plateau values for the cortisone-d5 and cortisol-d5 administration were almost identical (about 0.43) and (2) dosing with only 5 mg of the deuterium-labeled steroids suppressed the plasma concentrations of endogenous cortisol and cortisone.
authors.affiliation: Department of Medicinal Chemistry and Clinical Pharmacy, School of Pharmacy, Tokyo, University of Pharmacy and Life Science. kasuyay@ps.toyaku.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Kasuya
authors.forename: H
authors.initials: H
authors.lastname: Ishimaru
authors.forename: H
authors.initials: H
authors.lastname: Shibasaki
authors.forename: T
authors.initials: T
authors.lastname: Furuta
mesh_terms: D000284:Administration, Oral; D000328:Adult; D003348:Cortisone / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D003903:Deuterium; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006854:Hydrocortisone / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D007700:Kinetics; D008297:Male
chemical_list: D003903:Deuterium; D003348:Cortisone; D006854:Hydrocortisone