The presence of 19-norandrostenedione and its sulphate form in yolk-sac fluid of the early equine conceptus.
J Steroid Biochem Mol Biol
; 108(1-2): 149-54, 2008 Jan.
Article
em En
| MEDLINE
| ID: mdl-17980578
ABSTRACT
C(18) neutral steroid formation by cytochrome P450 aromatase has been recorded for several equine and porcine tissues. High activity of P450 aromatase is reflected in the quantities of estrogens in yolk-sac (y-s) fluid of early equine conceptuses. In a previous study of y-s fluid we detected large amounts of androgens by radioimmunoassay (RIA), using an antiserum for androstenedione (A(4)). Here, we report that RIA, following chromatography, gave tentative identification of the major peak as norandrostenedione (19-norA) not as A(4). Furthermore, even greater quantities of 19-norA seemed to be present in y-s fluid as a sulphoconjugate, as noted from extraction, solvolysis, HPLC, followed by RIA. Confirmation of these unusual findings was attained after further purification with two HPLC systems and definitive identification by LC-MS with an authentic standard of 19-norA. Initial extraction of the steroid sulphate as a methylene-blue complex also yielded 19-norA suggesting that the 3-enol form had enabled sulphoconjugation. The biological significance of retention mainly as a sulphate is not known; however, the large amounts of 19-norA found in the fluid accords well with reports on the catalytic activity shown in vitro by the blastocyst isozyme of P450 aromatase in the pig and horse.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sulfatos
/
Saco Vitelino
/
Feto
/
Cavalos
/
Androstenodiona
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
J Steroid Biochem Mol Biol
Ano de publicação:
2008
Tipo de documento:
Article