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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
22/06/2017 |
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Data da última atualização: |
22/06/2017 |
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Autoria: |
DOBSON, H.; ESSAWY, S. A.; ALAM, M. G. S. |
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Título: |
Suppression of LH response to gonadotrophin-releasing hormone or oestradiol by ACTH(1-24) treatment in anoestrous ewes. |
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Ano de publicação: |
1988 |
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Fonte/Imprenta: |
Journal of Endocrinology, v. 118, n. 2, p.193-197, Aug. 1988. |
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DOI: |
10.1677/joe.0.1180193 |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: Stress is known to result in lowered female reproductive efficiency. The objective of this study was to examine how increased pituitary-adrenal activity may influence gonadotrophin release in anoestrous ewes. Various doses (0.06-1.0 mg) of a synthetic adrenocorticotrophic hormone (ACTH(1-24)) preparation were injected into ewes 30 min or 3 h before an i.v. injection of 500 ng gonadotrophin-releasing hormone (GnRH). The LH response to GnRH given 30 min after ACTH(1-24) was similar to that after GnRH alone, whereas the response 3 h after ACTH(1-24) was significantly lower, irrespective of the dose of ACTH(1-24). At 30 min and 3 h after ACTH(1-24) the concentrations of cortisol exceeded 50 nmol/l compared with baseline values of less than 10 nmol/l. The effect of ACTH(1-24) on oestradiol-induced LH release was also examined. Those ewes receiving 0.8 mg ACTH(1-24) depot and 50 micrograms oestradiol benzoate simultaneously had a preovulatory-type increase in LH 14-20 h later, similar to when oestradiol benzoate was given alone. None of the ewes receiving an additional 0.8 mg ACTH(1-24) depot 10 h after oestradiol benzoate had increases in LH concentration. The cortisol concentrations in all ewes receiving either one or two injections of ACTH(1-24) were greater than 35 nmol/l at 10 h after the oestradiol injection. However, concentrations of progesterone increased from 0.9 +/- 0.3 (S.E.M.) nmol/l at the time of the second ACTH(1-24) injection to 2.1 +/- 0.3 nmol/l after 2 h. MenosAbstract: Stress is known to result in lowered female reproductive efficiency. The objective of this study was to examine how increased pituitary-adrenal activity may influence gonadotrophin release in anoestrous ewes. Various doses (0.06-1.0 mg) of a synthetic adrenocorticotrophic hormone (ACTH(1-24)) preparation were injected into ewes 30 min or 3 h before an i.v. injection of 500 ng gonadotrophin-releasing hormone (GnRH). The LH response to GnRH given 30 min after ACTH(1-24) was similar to that after GnRH alone, whereas the response 3 h after ACTH(1-24) was significantly lower, irrespective of the dose of ACTH(1-24). At 30 min and 3 h after ACTH(1-24) the concentrations of cortisol exceeded 50 nmol/l compared with baseline values of less than 10 nmol/l. The effect of ACTH(1-24) on oestradiol-induced LH release was also examined. Those ewes receiving 0.8 mg ACTH(1-24) depot and 50 micrograms oestradiol benzoate simultaneously had a preovulatory-type increase in LH 14-20 h later, similar to when oestradiol benzoate was given alone. None of the ewes receiving an additional 0.8 mg ACTH(1-24) depot 10 h after oestradiol benzoate had increases in LH concentration. The cortisol concentrations in all ewes receiving either one or two injections of ACTH(1-24) were greater than 35 nmol/l at 10 h after the oestradiol injection. However, concentrations of progesterone increased from 0.9 +/- 0.3 (S.E.M.) nmol/l at the time of the second ACTH(1-24) injection to 2.1 +/- 0.3 nmol/l after ... Mostrar Tudo |
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Palavras-Chave: |
Anoestrus; LH; Releasing hormones. |
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Thesagro: |
Estradiol. |
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Thesaurus Nal: |
Ewes; Pharmacology; Physiology; Pituitary hormones; Sheep. |
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Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
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Marc: |
LEADER 02248naa a2200265 a 4500
001 2071259
005 2017-06-22
008 1988 bl uuuu u00u1 u #d
024 7 $a10.1677/joe.0.1180193$2DOI
100 1 $aDOBSON, H.
245 $aSuppression of LH response to gonadotrophin-releasing hormone or oestradiol by ACTH(1-24) treatment in anoestrous ewes.
260 $c1988
520 $aAbstract: Stress is known to result in lowered female reproductive efficiency. The objective of this study was to examine how increased pituitary-adrenal activity may influence gonadotrophin release in anoestrous ewes. Various doses (0.06-1.0 mg) of a synthetic adrenocorticotrophic hormone (ACTH(1-24)) preparation were injected into ewes 30 min or 3 h before an i.v. injection of 500 ng gonadotrophin-releasing hormone (GnRH). The LH response to GnRH given 30 min after ACTH(1-24) was similar to that after GnRH alone, whereas the response 3 h after ACTH(1-24) was significantly lower, irrespective of the dose of ACTH(1-24). At 30 min and 3 h after ACTH(1-24) the concentrations of cortisol exceeded 50 nmol/l compared with baseline values of less than 10 nmol/l. The effect of ACTH(1-24) on oestradiol-induced LH release was also examined. Those ewes receiving 0.8 mg ACTH(1-24) depot and 50 micrograms oestradiol benzoate simultaneously had a preovulatory-type increase in LH 14-20 h later, similar to when oestradiol benzoate was given alone. None of the ewes receiving an additional 0.8 mg ACTH(1-24) depot 10 h after oestradiol benzoate had increases in LH concentration. The cortisol concentrations in all ewes receiving either one or two injections of ACTH(1-24) were greater than 35 nmol/l at 10 h after the oestradiol injection. However, concentrations of progesterone increased from 0.9 +/- 0.3 (S.E.M.) nmol/l at the time of the second ACTH(1-24) injection to 2.1 +/- 0.3 nmol/l after 2 h.
650 $aEwes
650 $aPharmacology
650 $aPhysiology
650 $aPituitary hormones
650 $aSheep
650 $aEstradiol
653 $aAnoestrus
653 $aLH
653 $aReleasing hormones
700 1 $aESSAWY, S. A.
700 1 $aALAM, M. G. S.
773 $tJournal of Endocrinology$gv. 118, n. 2, p.193-197, Aug. 1988.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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