Degradation of urine samples and its influence on the 13C/12C ratios of excreted steroids

Titel in Übersetzung: Abbau von Urinproben und ihr Einfluss auf die 13C/12C-Kennzahlen von ausgeschiedenen Steroiden

Publikation: Beitrag in FachzeitschriftZeitschriftenaufsätzeForschungBegutachtung

Abstract

The degradation processes in deficiently stored urine samples are well investigated regarding steroid concentrations and diagnostic ratios, such as the quotient of testosterone divided by epitestosterone. In contrast, nothing is known about the influence on carbon isotope ratios (CIR) by inappropriate storage conditions. In general, it is assumed that degradation, i.e. deconjugation or dehydrogenation, does not change CIR and thus CIR can be used in cases where the steroid profile turns out to be invalid. Therefore, the CIR of urinary steroids was investigated in different urine samples during the course of degradation over a time period of six months. Several steroids excreted as glucuronides (androsterone (A), etiocholanolone (E), testosterone, pregnanediol (PD) and 5α- and 5β-androstane-3α,17β-diol) or sulfo-conjugated (A, E and androst-5-ene-3β,17β-diol (5EN17b)) were investigated together with their unconjugated correspondents (A, E, PD and 5EN17b) and the main dehydrogenation products (5α- and 5β-androstane-3,17-dion and androst-4-ene-3,17-dion). For this purpose, the exiting methods for CIR determination were extended and validated. In addition, the urinary concentrations of all investigated steroids were monitored. Particular attention was paid to dehydroepiandrosterone conjugated and unconjugated together with its degradation product 3α,5-cyclo-5α-androstan-6β-ol-17-one as here the strongest influence on CIR was expected. Verf.-Referat
Titel in ÜbersetzungAbbau von Urinproben und ihr Einfluss auf die 13C/12C-Kennzahlen von ausgeschiedenen Steroiden
OriginalspracheEnglisch
ZeitschriftDrug testing and analysis
Jahrgang2
Seiten (von - bis)620-629
Seitenumfang10
ISSN1942-7603
PublikationsstatusVeröffentlicht - 2010

Fachgebiete und Schlagwörter

  • Biochemie
  • Doping
  • Dopinganalyse
  • Dopingkontrolle
  • Dopingnachweis
  • Epitestosteron
  • Harnstoff
  • Isotop
  • Steroid
  • Testosteron
  • Urin
  • Urinausscheidung

Zitation