title: Simultaneous determination of androstenedione, 11beta-hydroxyandrostenedione, and testosterone in human plasma by stable isotope dilution mass spectrometry.
abstract: This study describes a GC-MS method for the simultaneous determination of androstenedione (AD), 11beta-hydroxyandrostenedione (11beta-OHAD), and testosterone (TS) in human plasma. [19,19,19-(2)H(3)]Androstenedione (AD-(2)H(3)), 11beta-hydroxy-[1,2,4,19-(13)C(4)]androstenedione (11beta-OHAD-(13)C(4)), and [1,16,16,17-(2)H(4)]testosterone (TS-(2)H(4)) were used as internal standards. Pentafluoropropionic (PFP) derivatization with good GC behavior was employed for the GC-MS analysis of the three steroids. The detection limit of the present GC-MS-SIM method was found to be 1 pg per injection for AD (S/N ratio=4.5), 5 pg for 11beta-OHAD (S/N ratio=5.0), and 1 pg for TS (S/N ratio=4.4), respectively. Calibration curves were linear from 0.22 to 2.80 ng/mL (r=0.9998) for AD, from 0.56 to 3.19 ng/mL (r=0.9996) for 11beta-OHAD, and from 2.05 to 10.3 ng/mL (r=0.9996) for TS. The intra- and inter-day assay reproducibilities in the amounts of the three androgens determined were in good agreement with the actual amounts added, the relative errors (R.E.) were -3.1 to 2.4%. The inter-assay relative standard deviation (R.S.D.) was less than 5.3%. The present method provides a sensitive and reliable technique for the simultaneous determination of AD, 11beta-OHAD, and TS in plasma. The method can be applied to pharmacokinetic and metabolic studies of androgens with a particular interest in evaluating the conversion of AD to 11beta-OHAD and the interconversion of AD and TS in humans.
authors.affiliation: Department of Medicinal Chemistry and Clinical Pharmacy, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan. yokokawa@ps.toyaku.ac.jp
authors.forename: Akitomo
authors.initials: A
authors.lastname: Yokokawa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Omori
authors.forename: Hiromi
authors.initials: H
authors.lastname: Shibasaki
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Shinohara
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Kasuya
authors.forename: Takashi
authors.initials: T
authors.lastname: Furuta
mesh_terms: D000735:Androstenedione / Q000097:blood* / Q000737:chemistry; D002247:Carbon Isotopes / Q000097:blood*; D003903:Deuterium / Q000097:blood*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D013739:Testosterone / Q000097:blood*
chemical_list: D002247:Carbon Isotopes; D013739:Testosterone; D000735:Androstenedione; D003903:Deuterium