[PMID]: | 23203422 |
[Au] Autor: | Regueira E; Sassone AG; Scaia MF; Volonteri MC; Ceballos NR |
[Ad] Endereço: | Laboratorio de Endocrinología Comparada, Departamento de Biodiversidad y Biología Experimental, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina. eleonoraregueira@gmail.com |
[Ti] Título: | Seasonal changes and regulation of the glucocorticoid receptor in the testis of the toad Rhinella arenarum. |
[So] Source: | J Exp Zool A Ecol Genet Physiol;319(1):39-52, 2013 Jan. |
[Is] ISSN: | 1932-5231 |
[Cp] País de publicação: | United States |
[La] Idioma: | eng |
[Ab] Resumo: | Several studies indicate that wild free-living vertebrates seasonally regulate plasma glucocorticoids. However, not only glucocorticoids but also the amount of receptors is important in determining biological responses. In this context, seasonal regulation of glucocorticoid receptor (GR) is crucial to modulate the response to glucocorticoids. Rhinella arenarum is an anuran exhibiting seasonal variations in plasma glucocorticoids and also in the number of binding sites (B(max)) of the testicular cytosolic GR. In this work, we evaluated if the annual pattern of GR protein in the testis varies seasonally and, by an in vitro approach, the role of glucocorticoids, androgens, and melatonin in the regulation of the GR B(max) and protein level. For this purpose, testes were treated with two physiological concentrations of melatonin (40 and 200 pg/ml), with or without luzindole (melatonin-receptor antagonist); with testosterone, cyanoketone (inhibitor of steroidogenesis) or casodex (androgen-receptor antagonist); or with dexamethasone or RU486 (GR antagonist). After treatments, B(max) and protein level were determined by the binding of [(3)H]dexamethasone and Western blot, respectively. Results showed that GR protein decreases in the winter. The in vitro treatment with melatonin produced a biphasic effect on the B(max) with the lowest concentration decreasing this parameter by a receptor-mediated mechanism. However, melatonin had no effect on the GR protein level. Conversely, a high concentration of dexamethasone up-regulated the GR protein and androgens neither changed the B(max) nor the protein level. These findings suggest that seasonal changes in plasma melatonin and glucocorticoids modulate the effect of glucocorticoids in the testis of R. arenarum. |
[Mh] Termos MeSH primário: |
Bufo marinus/metabolismo Glucocorticoides/metabolismo Receptores de Glucocorticoides/metabolismo Testículo/metabolismo
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[Mh] Termos MeSH secundário: |
Anilidas/farmacologia Animais Sítios de Ligação Western Blotting/veterinária Cianocetona/farmacologia Dexametasona/farmacologia Regulação da Expressão Gênica Glucocorticoides/sangue Técnicas In Vitro Cinética Masculino Melatonina/metabolismo Melatonina/farmacologia Mifepristona/farmacologia Nitrilos/farmacologia Distribuição Aleatória Receptores de Glucocorticoides/genética Estações do Ano Testículo/efeitos dos fármacos Testosterona/metabolismo Testosterona/farmacologia Compostos de Tosil/farmacologia Triptaminas/farmacologia
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[Pt] Tipo de publicação: | JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T |
[Nm] Nome de substância:
| 0 (Anilides); 0 (Glucocorticoids); 0 (Nitriles); 0 (Receptors, Glucocorticoid); 0 (Tosyl Compounds); 0 (Tryptamines); 117946-91-5 (luzindole); 320T6RNW1F (Mifepristone); 3XMK78S47O (Testosterone); 4248-66-2 (Cyanoketone); 7S5I7G3JQL (Dexamethasone); A0Z3NAU9DP (bicalutamide); JL5DK93RCL (Melatonin) |
[Em] Mês de entrada: | 1306 |
[Cu] Atualização por classe: | 141120 |
[Lr] Data última revisão:
| 141120 |
[Sb] Subgrupo de revista: | IM |
[Da] Data de entrada para processamento: | 121204 |
[St] Status: | MEDLINE |
[do] DOI: | 10.1002/jez.1772 |
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