Differential regulation of tyrosine hydroxylase and estradiol receptor expression in the rainbow trout brain.
Mol Cell Endocrinol
; 199(1-2): 37-47, 2003 Jan 31.
Article
em En
| MEDLINE
| ID: mdl-12581878
ABSTRACT
In numerous fish species, dopamine has been found to strongly inhibit gonadotropin release. Among the enzymes that regulate dopamine turnover, tyrosine hydroxylase (TH), the rate-limiting anabolic enzyme, could be a target for endocrine feedback regulation. Since dopamine turnover is stimulated by estradiol in rainbow trout, we have investigated the effect of estradiol on TH and estradiol receptor expression. In situ hybridization was used to quantify mRNA levels in the brain of ovariectomized female rainbow trout implanted or not with estradiol pellets. We demonstrated that preoptic TH and estradiol receptor mRNA levels are greatly decreased by gonadectomy during vitellogenesis. For TH expression, this effect was reversed in part by estradiol supplementation. We have also confirmed the existence of an inhibitory gonadal feedback on FSH secretion, mediated by estradiol. The stimulating effect of estradiol on TH expression found in this study could be a pathway involved in gonadal feedback on gonadotropin release.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tirosina 3-Mono-Oxigenase
/
Encéfalo
/
Receptores de Estradiol
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Regulação da Expressão Gênica
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Oncorhynchus mykiss
Limite:
Animals
Idioma:
En
Ano de publicação:
2003
Tipo de documento:
Article