Idioma:

Hypothalamic Effects of Tamoxifen on Oestrogen Regulation of Luteinising Hormone and Prolactin Secretion in Female Rats

Aquino, N. S. S. ; Araujo-Lopes, R. ; Batista, I. A. R. ; Henriques, P. C. ; Poletini, M. O. ; Franci, C. R. ; Reis, A. M. ; Szawka, R. E.

Journal of neuroendocrinology, 2016-01, Vol.28 (1), p.np-n/a [Periódico revisado por pares]

United States: Blackwell Publishing Ltd

Texto completo disponível

Citações Citado por

Enviar para

Título:
Hypothalamic Effects of Tamoxifen on Oestrogen Regulation of Luteinising Hormone and Prolactin Secretion in Female Rats
Autor: Aquino, N. S. S. ; Araujo-Lopes, R. ; Batista, I. A. R. ; Henriques, P. C. ; Poletini, M. O. ; Franci, C. R. ; Reis, A. M. ; Szawka, R. E.
Assuntos: Animals ; Arcuate Nucleus of Hypothalamus - drug effects ; Arcuate Nucleus of Hypothalamus - metabolism ; Estradiol - pharmacology ; Female ; hypothalamus ; Hypothalamus - drug effects ; Hypothalamus - metabolism ; Kisspeptins - metabolism ; luteinising hormone ; Luteinizing Hormone - blood ; oestradiol ; Ovariectomy ; Phosphorylation - drug effects ; prolactin ; Prolactin - blood ; Rats ; Rats, Wistar ; Receptors, Progesterone - metabolism ; Selective Estrogen Receptor Modulators - pharmacology ; tamoxifen ; Tamoxifen - pharmacology ; Tyrosine 3-Monooxygenase - metabolism
É parte de: Journal of neuroendocrinology, 2016-01, Vol.28 (1), p.np-n/a
Notas: ark:/67375/WNG-D95XHK1F-1
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
istex:DB1D6A6A64D6C0EFA3D08DC10FACF8C656A04689
ArticleID:JNE12338
Pró-Reitoria de Pesquisa Universidade Federal de Minas Gerais (PRPq-UFMG)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
Descrição: Oestradiol (E2) acts in the hypothalamus to regulate luteinising hormone (LH) and prolactin (PRL) secretion. Tamoxifen (TX) has been extensively used as a selective oestrogen receptor modulator, although its neuroendocrine effects remain poorly understood. In the present study, we investigated the hypothalamic effects of TX in rats under low or high circulating E2 levels. Ovariectomised (OVX) rats treated with oil, E2 or TX, or E2 plus TX, were evaluated for hormonal secretion and immunohistochemical analyses in hypothalamic areas. Both E2 and TX reduced LH levels, whereas TX blocked the E2‐induced surges of LH and PRL. TX prevented the E2‐induced expression of progesterone receptor (PR) in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC), although it did not alter PR expression in OVX rats. TX blocked the E2 induction of c‐Fos in AVPV neurones, consistent with the suppression of LH surge. However, TX failed to prevent E2 inhibition of kisspeptin expression in the ARC. In association with the blockade of PRL surge, TX increased the phosphorylation of tyrosine hydroxylase (TH) in the median eminence of OVX, E2‐treated rats. TX also precluded the E2‐induced increase in TH expression in the ARC. In all immunohistochemical analyses, TX treatment in OVX rats caused no measurable effect on the hypothalamus. Thus, TX is able to prevent the positive‐ but not negative‐feedback effect of E2 on the hypothalamus. TX also blocks the effects of E2 on tuberoinfundibular dopaminergic neurones and PRL secretion. These findings further characterise the anti‐oestrogenic actions of TX in the hypothalamus and provide new information on the oestrogenic regulation of LH and PRL.
Editor: United States: Blackwell Publishing Ltd
Idioma: Inglês

Links

View this record in MEDLINE/PubMed

Voltar para lista de resultados

Realização: Logos de Redes Sociais:

Hypothalamic Effects of Tamoxifen on Oestrogen Regulation of Luteinising Hormone and Prolactin Secretion in Female Rats

Aquino, N. S. S. ; Araujo-Lopes, R. ; Batista, I. A. R. ; Henriques, P. C. ; Poletini, M. O. ; Franci, C. R. ; Reis, A. M. ; Szawka, R. E.

United States: Blackwell Publishing Ltd

Buscando em bases de dados remotas. Favor aguardar.