Estrogens and male reproduction: a new concept



Título del documento: Estrogens and male reproduction: a new concept
Revista: Brazilian journal of medical and biological research
Base de datos: PERIÓDICA
Número de sistema: 000350935
ISSN: 0100-879X
Autores: 1
1
2
1
1
3
1
1
Instituciones: 1Universite de Caen Basse–Normandie, Departement de Biochimie, Caen, Calvados. Francia
2Turku University, Physiology Department, Turku, Turun-Porin. Finlandia
3Centre Hospitalier Universitaire Saint Antoine, París. Francia
Año:
Periodo: Jun
Volumen: 40
Número: 6
Paginación: 761-768
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Analítico, descriptivo
Resumen en inglés The mammalian testis serves two main functions: production of spermatozoa and synthesis of steroids; among them estrogens are the end products obtained from the irreversible transformation of androgens by a microsomal enzymatic complex named aromatase. The aromatase is encoded by a single gene (cyp19) in humans which contains 18 exons, 9 of them being translated. In rats, the aromatase activity is mainly located in Sertoli cells of immature rats and then in Leydig cells of adult rats. We have demonstrated that germ cells represent an important source of estrogens: the amount of P450arom transcript is 3-fold higher in pachytene spermatocytes compared to gonocytes or round spermatids; conversely, aromatase activity is more intense in haploid cells. Male germ cells of mice, bank voles, bears, and monkeys express aromatase. In humans, we have shown the presence of a biologically active aromatase and of estrogen receptors (a and ß) in ejaculated spermatozoa and in immature germ cells in addition to Leydig cells. Moreover, we have demonstrated that the amount of P450arom transcripts is 30% lower in immotile than in motile spermatozoa. Alterations of spermatogenesis in terms of number and motility of spermatozoa have been described in men genetically deficient in aromatase. These last observations, together with our data showing a significant decrease of aromatase in immotile spermatozoa, suggest that aromatase could be involved in the acquisition of sperm motility. Thus, taking into account the widespread localization of aromatase and estrogen receptors in testicular cells, it is obvious that, besides gonadotrophins and androgens, estrogens produced locally should be considered to be physiologically relevant hormones involved in the regulation of spermatogenesis and spermiogenesis
Disciplinas: Biología
Palabras clave: Fisiología animal,
Mamíferos,
Reproducción y desarrollo,
Aromatasa,
Estrógenos,
Receptores hormonales,
Fertilidad,
Espermatogénesis
Keyword: Biology,
Animal physiology,
Mammals,
Reproduction and development,
Aromatase,
Estrogens,
Hormonal receptors,
Fertility,
Spermatogenesis
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