The use of stable isotopes and gas chromatography/mass spectrometry in the identification of steroid metabolites in the equine

Journal Article · Mon Oct 01 00:00:00 EDT 1990 · Steroids; (USA)

DOI:https://doi.org/10.1016/0039-128X(90)90011-Y· OSTI ID:6060980

Houghton, E; Dumasia, M C; Teale, P; Smith, S J; Cox, J; Marshall, D; Gower, D B ^[1]

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1. Horseracing Forensic Laboratory, Newmarket, Suffolk (England)

Stable isotope gas chromatography/mass spectrometry has been used successfully in the elucidation of structures of urinary steroid metabolites in the horse and in the identification of metabolites isolated from in vivo perfusion and in vitro incubation studies using equine tissue preparations. Deuterium-labeled steroids, testosterone, dehydroepiandrosterone, and 5-androstene-3 beta,17 beta-diol have been synthesized by base-catalyzed isotope exchange methods and the products characterized by gas chromatography/mass spectrometry. (16,16(-2)H2)Dehydroepiandrosterone (plus radiolabeled dehydroepiandrosterone) was perfused into a testicular artery of a pony stallion and was shown to be metabolized into 2H2-labeled testosterone, 4-androstenedione, isomers of 5-androstene-3,17-diol, 19-hydroxytestosterone, and 19-hydroxy-4-androstenedione. In further studies, equine testicular minces have been incubated with 2H2-labeled and radiolabeled dehydroepiandrosterone and 5-androstene-3 beta, 17 beta-diol. The metabolites, whose identity was confirmed by stable isotope gas chromatography/mass spectrometry, proved the interconversion of the two substrates, as well as formation of testosterone and 4-androstenedione. The aromatization of dehydroepiandrosterone was also confirmed, together with the formation of an isomer of 5(10)-estrene-3,17-diol from both substrates showing 19-demethylation without concomitant aromatization. In studies of the feto-placental unit, the allantochorion was shown to aromatize (2H5)testosterone to (2H4)estradiol, the loss of one 2H from the substrate being consistent with aromatization of the A ring. The formation of 6-hydroxyestradiol was also confirmed in this study. The same technique has been valuable in determining the structure of two metabolites of nandrolone isolated from horse urine.

• OSTI ID: 6060980
• Journal Information: Steroids; (USA), Vol. 55:10; ISSN 0039-128X
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
METABOLITES
MOLECULAR STRUCTURE
STEROIDS
METABOLISM
ANDROSTENEDIONE
ANDROSTERONE
AROMATIZATION
CHEMICAL PREPARATION
DEUTERIUM
ESTRADIOL
GAS CHROMATOGRAPHY
HORSES
MASS SPECTROSCOPY
PERFUSED TISSUES
PREGNANCY
TESTES
TESTOSTERONE
TRACER TECHNIQUES
ANDROGENS
ANDROSTANES
ANIMAL TISSUES
ANIMALS
BODY
CHEMICAL REACTIONS
CHROMATOGRAPHY
ESTRANES
ESTROGENS
GONADS
HORMONES
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
KETONES
LIGHT NUCLEI
MALE GENITALS
MAMMALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
SEPARATION PROCESSES
SPECTROSCOPY
STABLE ISOTOPES
STEROID HORMONES
SYNTHESIS
TISSUES
VERTEBRATES
550501* - Metabolism- Tracer Techniques