title: Influences of β-HCG administration on carbon isotope ratios of endogenous urinary steroids.
abstract: Several factors influencing the carbon isotope ratios (CIR) of endogenous urinary steroids have been identified in recent years. One of these should be the metabolism of steroids inside the body involving numerous different enzymes. A detailed look at this metabolism taking into account differences found between steroids excreted as glucuronides or as sulphates and hydrogen isotope ratios of different steroids pointed out possibility of unequal CIR at the main production sites inside the male body - the testes and the adrenal glands. By administration of β-HCG it is possible to strongly stimulate the steroid production within the testes without influencing the production at the adrenal glands. Therefore, this treatment should result in changed CIR of urinary androgens in contrast to the undisturbed pre-treatment values. Four male volunteers received three injections of β-HCG over a time course of 5 days and collected their urine samples at defined intervals after the last administration. Those samples showing the largest response in contrast to the pre-administration urines were identified by steroid profile measurements and subsequent analysed by GC/C/IRMS. CIR of androsterone, etiocholanolone, testosterone, 5α- and 5β-androstanediol and pregnanediol were compared. While pregnanediol was not influenced, most of the investigated androgens showed depleted values after treatment. The majority of differences were found to be statistically significant and nearly all showed the expected trend towards more depleted δ(13)C-values. These results support the hypothesis of different CIR at different production sites inside the human body. The impact of these findings on doping control analysis will be discussed.
authors.affiliation: Swiss Laboratory for Doping Analysis, University Center of Legal Medicine, Geneva and Lausanne, Centre Hospitalier Universitaire Vaudois and University Lausanne, Ch. des Croisettes 22, CH-1066 Epalinges, Switzerland. thomas.piper@chuv.ch
authors.forename: Thomas
authors.initials: T
authors.lastname: Piper
authors.forename: Norbert
authors.initials: N
authors.lastname: Baume
authors.forename: Emanuel
authors.initials: E
authors.lastname: Strahm
authors.forename: Caroline
authors.initials: C
authors.lastname: Emery
authors.forename: Martial
authors.initials: M
authors.lastname: Saugy
mesh_terms: D000328:Adult; D002247:Carbon Isotopes / Q000032:analysis; D002784:Cholesterol / Q000652:urine; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000008:administration & dosage* / Q000494:pharmacology*; D004300:Doping in Sports / Q000517:prevention & control; D006801:Humans; D008297:Male; D013254:Steroid 17-alpha-Hydroxylase / Q000652:urine; D013256:Steroids / Q000737:chemistry* / Q000652:urine*; D013431:Sulfates / Q000737:chemistry; D016482:Urinalysis; D055815:Young Adult
chemical_list: D002247:Carbon Isotopes; D018997:Chorionic Gonadotropin, beta Subunit, Human; D013256:Steroids; D013431:Sulfates; D002784:Cholesterol; D013254:Steroid 17-alpha-Hydroxylase