FSH titers are higher in female infantile rats than in male age-matched rats. At this period the gonadotropin is under a particular regulation which is sexually differentiated. We had previously shown that the serotonin precursor 5-hydroxytryptophan and the narcotic antagonist, naloxone, increased FSH titers in females and not in males of 12 days of age, and that the response was absent at birth, and disappeared as the female matured. In the present work we examined if sexual differentiation of brain structures was involved in conditioning FSH response in infantile 12 day old rats. Female rats androgenised at birth with testosterone propionate, and male rats orchidectomized at birth were used for this purpose. It was found that androgenization of females abolished the FSH response to both 5-hydroxytryptophan and naloxone, while castration of males at birth induced a release of FSH by both drugs in males at 12 days. A similar pattern of response was obtained for LH, while no sexual differences in prolactin regulation by either 5-hydroxytryptophan or naloxone were observed. These results indicate that, as it has been described for LH, sexual dimorphism resulting from the early organizational effects of neonatal steroids is, at least in part, responsible for the different response of FSH to 5-hydroxytryptophan and naloxone in infantile rats.
Documento: | Artículo |
Título: | Sexual differentiation of the brain is involved in 5-hydroxytryptophan- and naloxone-induced FSH release in the infantile rat |
Autor: | Becu-Villalobos, D.; Lacau-Mengido, I.M.; Libertun, C. |
Filiación: | Instituto de Biologia y Medicina Experimental, Obligado 2490, 1428 Buenos Aires, Argentina |
Palabras clave: | follitropin; luteinizing hormone; naloxone; serotonin; testosterone; animal experiment; article; brain; castration; controlled study; female; male; newborn; nonhuman; orchiectomy; priority journal; rat; sexual development; subcutaneous drug administration |
Año: | 1990 |
Volumen: | 12 |
Número: | 6 |
Página de inicio: | 435 |
Página de fin: | 441 |
Título revista: | Neuroendocrinology Letters |
Título revista abreviado: | NEUROENDOCRINOL. LETT. |
ISSN: | 0172780X |
CODEN: | NLETD |
CAS: | follitropin, 9002-68-0; luteinizing hormone, 39341-83-8, 9002-67-9; naloxone, 357-08-4, 465-65-6; serotonin, 50-67-9; testosterone, 58-22-0 |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0172780X_v12_n6_p435_BecuVillalobos |