Relationships between liver testosterone receptor isoforms and aromatase activity in female green frog, Rana esculenta.
Life Sci
; 67(4): 373-82, 2000 Jun 16.
Article
en En
| MEDLINE
| ID: mdl-11003047
ABSTRACT
Testosterone receptors (AR) are present in the liver of the female green frog, Rana esculenta, which resolve into two fractions (A and B) by ion-exchange chromatography. Fraction A is primarily located in the nuclei, fraction B predominates in the cytosols, and both fractions show a high affinity and specificity for testosterone. Liver AR fraction levels vary dramatically during the frog sexual cycle. Fraction A levels are high only when the liver is engaged in vitellogenin production and the plasma testosterone levels are high they are maximal when aromatase activity is most intense. Fraction B levels are high when the liver is not producing vitellogenin and the plasma testosterone levels are minimal. In addition, in vivo experiments carried out on ovariectomized females treated with testosterone show that testosterone induces both fraction A and liver aromatase activity. This induction may be a step in the process that allows the liver to obtain estrogen from plasma testosterone which induces vitellogenin synthesis.
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Colección:
01-internacional
Asunto principal:
Aromatasa
/
Receptores Androgénicos
/
Hígado
Límite:
Animals
Idioma:
En
Revista:
Life Sci
Año:
2000
Tipo del documento:
Article
País de afiliación:
Italia