• Medientyp: E-Artikel
  • Titel: Specific Deuterium Labelling and Computerized Gas Chromatography‐Mass Spectrometry in Studies on the Metabolism in vivo of a Steroid Sulphate in the Rat
  • Beteiligte: BAILLIE, Thomas A.; ERIKSSON, Håkan; SJÖVALL, Jan; HERZ, Josef E.
  • Erschienen: Wiley, 1975
  • Erschienen in: European Journal of Biochemistry
  • Umfang: 157-165
  • Sprache: Englisch
  • DOI: 10.1111/j.1432-1033.1975.tb02148.x
  • ISSN: 0014-2956; 1432-1033
  • Schlagwörter: Biochemistry
  • Zusammenfassung: <jats:p>The metabolism of 3β‐hydroxy‐5α‐pregnan‐20‐one sulphate was studied in bile fistula rats and in isolated perfused livers. Computerized gas chromatography‐mass spectrometry, in combination with specific deuterium‐labelling, was employed to follow the metabolic transformations.</jats:p><jats:p>Male animals excreted metabolites into bile more rapidly than females, a finding which could be correlated with the preferential formation of glucuronide conjugates in the male liver.</jats:p><jats:p>The major metabolic pathway in male rats involved the steps: hydrolysis, 2α‐hydroxylation, oxidoreduction at C‐3 and glucuronide conjugation, yielding 2α,3α‐dihydroxy‐5α‐pregnan‐20‐one glucuronide as the major metabolite. Only traces of the injected steroid sulphate were detected in bile from male animals. In contrast, the administered compound was the major steroid excreted in bile of female rats, where the main metabolite was identified as 3β,15β‐dihydroxy‐5α‐pregnan‐20‐one sulphate. A minor metabolite, 3β,16α‐dihydroxy‐5α‐pregnan‐20‐one, was found as a mono‐sulphate in female rats and as both a disulphate and a glucuronide conjugate in male rats. The deuterium content of the sulphated 15β‐ and 16α‐hydroxylated metabolites was consistent with metabolic pathways involving direct hydroxylation of the injected steroid sulphate.</jats:p><jats:p>The results obtained from the liver perfusions were essentially the same as those from the experiments with bile fistula animals. This indicates that all the observed metabolic reactions took place in the liver.</jats:p>
  • Beschreibung: <jats:p>The metabolism of 3β‐hydroxy‐5α‐pregnan‐20‐one sulphate was studied in bile fistula rats and in isolated perfused livers. Computerized gas chromatography‐mass spectrometry, in combination with specific deuterium‐labelling, was employed to follow the metabolic transformations.</jats:p><jats:p>Male animals excreted metabolites into bile more rapidly than females, a finding which could be correlated with the preferential formation of glucuronide conjugates in the male liver.</jats:p><jats:p>The major metabolic pathway in male rats involved the steps: hydrolysis, 2α‐hydroxylation, oxidoreduction at C‐3 and glucuronide conjugation, yielding 2α,3α‐dihydroxy‐5α‐pregnan‐20‐one glucuronide as the major metabolite. Only traces of the injected steroid sulphate were detected in bile from male animals. In contrast, the administered compound was the major steroid excreted in bile of female rats, where the main metabolite was identified as 3β,15β‐dihydroxy‐5α‐pregnan‐20‐one sulphate. A minor metabolite, 3β,16α‐dihydroxy‐5α‐pregnan‐20‐one, was found as a mono‐sulphate in female rats and as both a disulphate and a glucuronide conjugate in male rats. The deuterium content of the sulphated 15β‐ and 16α‐hydroxylated metabolites was consistent with metabolic pathways involving direct hydroxylation of the injected steroid sulphate.</jats:p><jats:p>The results obtained from the liver perfusions were essentially the same as those from the experiments with bile fistula animals. This indicates that all the observed metabolic reactions took place in the liver.</jats:p>
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