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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
06/11/2002 |
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Data da última atualização: |
06/11/2002 |
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Autoria: |
DALEY, C. A.; SAKURAI, H.; ADAMS, B. M.; ADAMS, T. E. |
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Título: |
Effect of stress-like concentrations of cortisol on gonadotroph function in orchidectomized sheep. |
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Ano de publicação: |
1999 |
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Fonte/Imprenta: |
Biology of Reproduction, v. 60, n. 1, p. 158-163, 1999. |
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Idioma: |
Inglês |
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Conteúdo: |
The effect of stress-like concentrations of cortisol (C) on the feedback potency of estradiol (E,) was assessed using 32 orchidectomized sheep (wethers) assigned at random to 1 of 4 treatment groups in a 2 x 2 factorial design. Wethers received C (3.6 mg/50 kg per hour; groups 2 and 4) or a comparable volume of C delivery vehicle (groups 1 and 3) as a continuous infusion for 7 days. During the final 48 h of infusion, wethers received E2 (0.3 ug/50 kg/h; groups 3 and 4) or E2 delivery vehicle (groups 1 and 2). The pattern of LH secretion was assessed during a 4 h period of intensive blood collection beginning 44 h after initiation of E2 infusion. Gonadotroph responsiveness (LH secretion induced by GnRH challenge [500 ng, i.v.]) was determined 48 h after E2 delivery was begun. Although lhe frequency of secretory episodes of LH was not affected (p > 0.05) by infusion of C or E2 alone, LH pulse frequency was significantly decreased in wethers receiving C and E2 in combination. In contrast, neither the magnitude of basal gonadotroph responsiveness nor the extent of E2-dependent augmentation of responsiveness was significantly affected by stress-like concentrations of C. In a second experiment, the effect of C on the magnitude of E2-induced in- crease in pituitary concentration of GnRH receptor and GnRH receptor mRNA was assessed using 32 additional wethers. Continuous infusion of E2 for 48 h increased (p < 0.05) tissue concentrations of GnRH receptor and GnRH receptor mRNA. Con- current delivery of C did not affect (p > 0.05) E2-induced in- crease in GnRH receptor mRNA but significantly reduced the magnitude of the E2-dependent increase in pituitary concentration of GnRH receptor. Collectively, these data indicate that stress-like concentrations of C enhance the negative feedback potency of E2 and reduce estrogen-dependent augmentation of the concentration of GnRH receptor in pituitary tissue. MenosThe effect of stress-like concentrations of cortisol (C) on the feedback potency of estradiol (E,) was assessed using 32 orchidectomized sheep (wethers) assigned at random to 1 of 4 treatment groups in a 2 x 2 factorial design. Wethers received C (3.6 mg/50 kg per hour; groups 2 and 4) or a comparable volume of C delivery vehicle (groups 1 and 3) as a continuous infusion for 7 days. During the final 48 h of infusion, wethers received E2 (0.3 ug/50 kg/h; groups 3 and 4) or E2 delivery vehicle (groups 1 and 2). The pattern of LH secretion was assessed during a 4 h period of intensive blood collection beginning 44 h after initiation of E2 infusion. Gonadotroph responsiveness (LH secretion induced by GnRH challenge [500 ng, i.v.]) was determined 48 h after E2 delivery was begun. Although lhe frequency of secretory episodes of LH was not affected (p > 0.05) by infusion of C or E2 alone, LH pulse frequency was significantly decreased in wethers receiving C and E2 in combination. In contrast, neither the magnitude of basal gonadotroph responsiveness nor the extent of E2-dependent augmentation of responsiveness was significantly affected by stress-like concentrations of C. In a second experiment, the effect of C on the magnitude of E2-induced in- crease in pituitary concentration of GnRH receptor and GnRH receptor mRNA was assessed using 32 additional wethers. Continuous infusion of E2 for 48 h increased (p < 0.05) tissue concentrations of GnRH receptor and GnRH receptor mRNA. Con- ... Mostrar Tudo |
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Palavras-Chave: |
Gonadotropina. |
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Thesagro: |
Hormônio; Ovino; Stress. |
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Thesaurus Nal: |
cortisol. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02515naa a2200217 a 4500
001 1528806
005 2002-11-06
008 1999 bl uuuu u00u1 u #d
100 1 $aDALEY, C. A.
245 $aEffect of stress-like concentrations of cortisol on gonadotroph function in orchidectomized sheep.
260 $c1999
520 $aThe effect of stress-like concentrations of cortisol (C) on the feedback potency of estradiol (E,) was assessed using 32 orchidectomized sheep (wethers) assigned at random to 1 of 4 treatment groups in a 2 x 2 factorial design. Wethers received C (3.6 mg/50 kg per hour; groups 2 and 4) or a comparable volume of C delivery vehicle (groups 1 and 3) as a continuous infusion for 7 days. During the final 48 h of infusion, wethers received E2 (0.3 ug/50 kg/h; groups 3 and 4) or E2 delivery vehicle (groups 1 and 2). The pattern of LH secretion was assessed during a 4 h period of intensive blood collection beginning 44 h after initiation of E2 infusion. Gonadotroph responsiveness (LH secretion induced by GnRH challenge [500 ng, i.v.]) was determined 48 h after E2 delivery was begun. Although lhe frequency of secretory episodes of LH was not affected (p > 0.05) by infusion of C or E2 alone, LH pulse frequency was significantly decreased in wethers receiving C and E2 in combination. In contrast, neither the magnitude of basal gonadotroph responsiveness nor the extent of E2-dependent augmentation of responsiveness was significantly affected by stress-like concentrations of C. In a second experiment, the effect of C on the magnitude of E2-induced in- crease in pituitary concentration of GnRH receptor and GnRH receptor mRNA was assessed using 32 additional wethers. Continuous infusion of E2 for 48 h increased (p < 0.05) tissue concentrations of GnRH receptor and GnRH receptor mRNA. Con- current delivery of C did not affect (p > 0.05) E2-induced in- crease in GnRH receptor mRNA but significantly reduced the magnitude of the E2-dependent increase in pituitary concentration of GnRH receptor. Collectively, these data indicate that stress-like concentrations of C enhance the negative feedback potency of E2 and reduce estrogen-dependent augmentation of the concentration of GnRH receptor in pituitary tissue.
650 $acortisol
650 $aHormônio
650 $aOvino
650 $aStress
653 $aGonadotropina
700 1 $aSAKURAI, H.
700 1 $aADAMS, B. M.
700 1 $aADAMS, T. E.
773 $tBiology of Reproduction$gv. 60, n. 1, p. 158-163, 1999.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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| Registros recuperados : 4 | |
| 4. |  | HOOGEN, J. van den; GEISEN, S.; ROUTH, D.; FERRIS, H.; TRAUNSPURGER, W.; WARDLER, D. A.; GOEDE, R. G. M. de; ADAMS, B. J.; AHMAD, W.; ANDRIUZZI, W. S.; BARDGETT, R. D.; BONKOWSKI, M.; HERRERA, R. C.; CARES, J. E.; CARUSO, R.; CAIXETA, L. de B.; CHEN, X.; COSTA, S. R.; CREAMER, R.; CASTRO, J. M. da C. e; DAM, M.; DJIGAL, D.; ESCUERM N.; GRIFFITHS, B. S.; GUTIÉRREZ, C.; HOHBERG, K.; KALINKINA, D.; KARDOL, P.; KERGUNTEUIL, A.; KORTHALS, G.; KRASHEVSKA, V.; KUDRIN, A. A.; LI, Q.; LIANG, W.; MAGILTON, M.; MARAIS, M.; MARTIN, J. A. R.; MATVEEVA, E.; MAYAD, E. H.; MULDER, C.; MULLIN, P.; NEILSON, R.; NGUYEN, T. A. D.; NIELSEN, U. N.; OKADA, H.; RIUS, J. E. P.; PAN, K.; PENEVA, V.; PELLISSIER, L.; SILVA, J. C. P. da; PITTELOUD, C.; POWERS, T. O.; POWERS, K.; QUIST, C. W.; RASMANN, S.; MORENO, S. S.; SCHEU, S.; SETALA, H.; SUSHCHUK, A.; TIUNOV, A. V.; TRAP, J.; PUTTEN, W. van der; VESTERGARD, M.; VILLENAVE, C.; WAEYENBERGE, L.; WALL, D. H.; WILSCHUT, R.; WRIGHT, D. G.; YANG, J.-I; CROWTHER, T. W. Soil nematode abundance and functional group composition at a global scale. Nature, v. 572, p. 194-206, aug. 2019.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Semiárido. |
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| Registros recuperados : 4 | |
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