Reproductive system: aromatase and estrogens.
Mol Cell Endocrinol
; 193(1-2): 137-43, 2002 Jul 31.
Article
en En
| MEDLINE
| ID: mdl-12161013
ABSTRACT
The cytochrome P450 aromatase (P450arom) is the terminal enzyme responsible for the formation of estrogens from androgens. In the rat testis we have immunolocalized the P450arom not only in Leydig cells but also in germ cells and especially in elongated spermatids. Related to the stage of germ cell maturation, we have shown that the level of P450arom transcripts decreases, it is much more abundant in pachytene spermatocytes (PS) than in mature germ cells whereas the aromatase activity is two- to fourfold greater in spermatozoa when compared to younger germ cell preparations. In rat germ cells, the aromatase gene expression is not only under androgen and cyclic AMP control but also subjected to cytokine (TNFalpha) and growth factor (TGFbeta) regulation. In the bank-vole testis we have evidenced a positive correlation between a fully developed spermatogenesis and a strong immunoreactivity for both P450arom and estrogen receptor (ERbeta) not only in Sertoli cells but also in PS and round spermatids (RS). Therefore, the aromatase gene expression and its translation in a fully active protein in rodent germ cells evidence an additional site for estrogen production within the testis. Our recent data showing that human ejaculated spermatozoa expressed specific transcripts for P450arom reinforced the observations reported in germ cells of other mammalian species. Together with the widespread distribution of ERs in testicular cells these data bring enlightenment on the hormonal regulation of spermatogenesis.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Testículo
/
Aromatasa
/
Estrógenos
Límite:
Animals
/
Humans
/
Male
Idioma:
En
Revista:
Mol Cell Endocrinol
Año:
2002
Tipo del documento:
Article
País de afiliación:
Francia