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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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Origem |
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Registro Completo
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Biblioteca(s): |
Embrapa Uva e Vinho. |
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Data corrente: |
31/10/2016 |
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Data da última atualização: |
06/05/2019 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
B - 3 |
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Autoria: |
MIELE, A. |
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Afiliação: |
ALBERTO MIELE, CNPUV. |
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Título: |
Grapevine yield components and composition of Isabel grape produced according to the organic and conventional systems. |
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Ano de publicação: |
2016 |
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Fonte/Imprenta: |
BIO Web of Conferences, v. 7., n. 01011[online], 2016. |
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DOI: |
10.1051/bioconf/20160701011 |
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Idioma: |
Inglês |
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Notas: |
Também publicado em: CONGRESSO MUNDIAL DA VINHA E DO VINHO, 39., 2016, Bento Gonçalves, RS. RS. Anais.... Bento Gonçalves, RS: OIV, 2016. Abstract 2016-1062, p. 44, 2016. |
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Conteúdo: |
There is an increasing demand for organic grapes by the juice industry of Serra Gaucha, Brazil. This region presents a humid and hot summer, ideal climatic conditions for the development of a number of diseases. To control such diseases and problems brought about by other organisms, growers apply pesticides on the grapevines which may leave residues in grapes. However, in general, grapes produced by organic system have lower yield, but there is a lack of research data on this subject. Thus, an experiment was carried out over three years in order to compare the yield components and the physicochemical composition of the must of Isabel grapes conducted in both production systems. When the grapes were ripe, variables related to yield components were evaluated, such as the number of clusters/vine, yield/vine and weight/cluster. Then the grapes were sampled and taken to the laboratory where they were crushed and the musts were centrifuged and analyzed. The 3-year data mean were submitted to correlation analysis and Principal Component Analysis. The results show that conventional grapevines produced 2.18 times more than organic. However, the grapes from the organic system had higher density, Brix, pH, Brix/titratable acidity ratio, P and Mg but lower K, and Ca varied little between both production systems. |
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Palavras-Chave: |
Diseases of plant; Fungi species; Uva Isabel. |
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Thesagro: |
Doenca de planta; Uva. |
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Categoria do assunto: |
A Sistemas de Cultivo |
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URL: |
https://www.alice.cnptia.embrapa.br/alice/bitstream/doc/1055651/1/bioconfoiv201601011.pdf
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Marc: |
LEADER 02119naa a2200205 a 4500
001 2055651
005 2019-05-06
008 2016 bl uuuu u00u1 u #d
024 7 $a10.1051/bioconf/20160701011$2DOI
100 1 $aMIELE, A.
245 $aGrapevine yield components and composition of Isabel grape produced according to the organic and conventional systems.$h[electronic resource]
260 $c2016
500 $aTambém publicado em: CONGRESSO MUNDIAL DA VINHA E DO VINHO, 39., 2016, Bento Gonçalves, RS. RS. Anais.... Bento Gonçalves, RS: OIV, 2016. Abstract 2016-1062, p. 44, 2016.
520 $aThere is an increasing demand for organic grapes by the juice industry of Serra Gaucha, Brazil. This region presents a humid and hot summer, ideal climatic conditions for the development of a number of diseases. To control such diseases and problems brought about by other organisms, growers apply pesticides on the grapevines which may leave residues in grapes. However, in general, grapes produced by organic system have lower yield, but there is a lack of research data on this subject. Thus, an experiment was carried out over three years in order to compare the yield components and the physicochemical composition of the must of Isabel grapes conducted in both production systems. When the grapes were ripe, variables related to yield components were evaluated, such as the number of clusters/vine, yield/vine and weight/cluster. Then the grapes were sampled and taken to the laboratory where they were crushed and the musts were centrifuged and analyzed. The 3-year data mean were submitted to correlation analysis and Principal Component Analysis. The results show that conventional grapevines produced 2.18 times more than organic. However, the grapes from the organic system had higher density, Brix, pH, Brix/titratable acidity ratio, P and Mg but lower K, and Ca varied little between both production systems.
650 $aDoenca de planta
650 $aUva
653 $aDiseases of plant
653 $aFungi species
653 $aUva Isabel
773 $tBIO Web of Conferences$gv. 7., n. 01011[online], 2016.
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Embrapa Uva e Vinho (CNPUV) |
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