Melatonin decreases estrogen receptor expression in the medial preoptic area of inbred (LSH/SsLak) golden hamsters.
Biol Reprod
; 47(6): 1082-90, 1992 Dec.
Article
en En
| MEDLINE
| ID: mdl-1493172
Daily late afternoon injections of melatonin (25 micrograms/day s.c.) were found to reduce the number of cells expressing estrogen receptor immunoreactivity in the medial preoptic area of ovariectomized inbred (LSH/SsLak) golden hamsters. Employing immunocytochemical analysis with the H222 monoclonal antibody to the human estrogen receptor, we examined the effects of melatonin on estrogen receptor expression in the hypothalamus, particularly the medial preoptic area, of ovariectomized virgin female hamsters. Analysis of the results showed that melatonin administration induced a 50-70% decrease in numbers of estrogen receptor-immunoreactive neurons in the medial preoptic area of ovariectomized female hamsters. Furthermore, an overall qualitative decrease in the intensity of estrogen receptor immunoreactivity was observed. In intact regularly cycling female hamsters used to monitor the efficacy of melatonin treatment, there were significant reductions in the serum levels of FSH, LH, and prolactin as measured by radioimmunoassay and in uterine and pituitary weights after 8 wk of melatonin treatment. These results suggest that melatonin may exert its anti-reproductive effects in hamsters by modulating estrogen receptor levels in medial preoptic area neurons, thus influencing steroid feedback mechanisms.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Área Preóptica
/
Receptores de Estrógenos
/
Melatonina
Tipo de estudio:
Qualitative_research
Límite:
Animals
Idioma:
En
Revista:
Biol Reprod
Año:
1992
Tipo del documento:
Article
Pais de publicación:
Estados Unidos