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 | Acesso ao texto completo restrito à biblioteca da Embrapa Caprinos e Ovinos. Para informações adicionais entre em contato com cnpc.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
01/08/1992 |
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Data da última atualização: |
28/06/2023 |
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Autoria: |
WILSON, P. R.; LAPWOOD, K. R. |
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Título: |
Studies of reproductive development in Romney rams: I. Basal levels and plasma profiles of LH, testosterone and prolactin. |
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Ano de publicação: |
1979 |
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Fonte/Imprenta: |
Biology of Reproduction, v. 20, n. 4, p. 965-970, 1979. |
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DOI: |
https://doi.org/10.1095/biolreprod20.4.965 |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: In a study of endocrine changes during reproductive development in rams, single plasma samples were collected at birth; then 4 samples, 30 min apart, were collected each 2 weeks from 2?32 weeks of age. Eight Romney rams from a group of 32 were selected at random for each bleeding and plasma LH, testosterone and prolactin levels were estimated by specific radioimmunoassays. Plasma LH levels rose to a peak at 6 weeks, decreased until 16 weeks and then remained relatively constant, while testosterone levels increased steadily from low levels at birth to highest levels at 28?32 weeks of age. Prolactin levels rose to a plateau by 6 weeks, remained high until 18 weeks and decreased gradually until 32 weeks. In a second experiment, 8 rams were sampled each 20 min for 8 h on the 6th, 14th and 22nd weeks of life and plasma LH, testosterone and prolactin concentrations measured. LH was secreted in a pulsatile manner and secretion rates were highest at 14 weeks of age. Testosterone peaks were observed following each LH peak at 14 and 22 weeks, but followed only 6 of 11 LH peaks at 6 weeks of age. Testosterone peak levels were highest at 22 weeks of age. A quantitative relationship was observed between testosterone peaks and preceding LH peaks at 14 and 22 weeks of age, but not at 6 weeks. Prolactin secretion profiles of prepubertal (6 weeks) and sexually maturing (14 and 22 weeks) rams were similar and levels fluctuated markedly at each age. A stress-induced elevation of plasma LH levels was observed in approximately 70% of animals sampled in both experiments, while the occurrence of similar elevations of plasma prolactin levels due to stressful procedures was confirmed. MenosAbstract: In a study of endocrine changes during reproductive development in rams, single plasma samples were collected at birth; then 4 samples, 30 min apart, were collected each 2 weeks from 2?32 weeks of age. Eight Romney rams from a group of 32 were selected at random for each bleeding and plasma LH, testosterone and prolactin levels were estimated by specific radioimmunoassays. Plasma LH levels rose to a peak at 6 weeks, decreased until 16 weeks and then remained relatively constant, while testosterone levels increased steadily from low levels at birth to highest levels at 28?32 weeks of age. Prolactin levels rose to a plateau by 6 weeks, remained high until 18 weeks and decreased gradually until 32 weeks. In a second experiment, 8 rams were sampled each 20 min for 8 h on the 6th, 14th and 22nd weeks of life and plasma LH, testosterone and prolactin concentrations measured. LH was secreted in a pulsatile manner and secretion rates were highest at 14 weeks of age. Testosterone peaks were observed following each LH peak at 14 and 22 weeks, but followed only 6 of 11 LH peaks at 6 weeks of age. Testosterone peak levels were highest at 22 weeks of age. A quantitative relationship was observed between testosterone peaks and preceding LH peaks at 14 and 22 weeks of age, but not at 6 weeks. Prolactin secretion profiles of prepubertal (6 weeks) and sexually maturing (14 and 22 weeks) rams were similar and levels fluctuated markedly at each age. A stress-induced elevation of plas... Mostrar Tudo |
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Thesagro: |
Endocrinologia; Fisiologia; Ovino; Reprodução. |
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Thesaurus Nal: |
Endocrinology; Hormones; Physiology; Prolactin; Reproduction; Sheep; Testosterone. |
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Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
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Marc: |
LEADER 02514naa a2200277 a 4500
001 1523676
005 2023-06-28
008 1979 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1095/biolreprod20.4.965$2DOI
100 1 $aWILSON, P. R.
245 $aStudies of reproductive development in Romney rams$bI. Basal levels and plasma profiles of LH, testosterone and prolactin.$h[electronic resource]
260 $c1979
520 $aAbstract: In a study of endocrine changes during reproductive development in rams, single plasma samples were collected at birth; then 4 samples, 30 min apart, were collected each 2 weeks from 2?32 weeks of age. Eight Romney rams from a group of 32 were selected at random for each bleeding and plasma LH, testosterone and prolactin levels were estimated by specific radioimmunoassays. Plasma LH levels rose to a peak at 6 weeks, decreased until 16 weeks and then remained relatively constant, while testosterone levels increased steadily from low levels at birth to highest levels at 28?32 weeks of age. Prolactin levels rose to a plateau by 6 weeks, remained high until 18 weeks and decreased gradually until 32 weeks. In a second experiment, 8 rams were sampled each 20 min for 8 h on the 6th, 14th and 22nd weeks of life and plasma LH, testosterone and prolactin concentrations measured. LH was secreted in a pulsatile manner and secretion rates were highest at 14 weeks of age. Testosterone peaks were observed following each LH peak at 14 and 22 weeks, but followed only 6 of 11 LH peaks at 6 weeks of age. Testosterone peak levels were highest at 22 weeks of age. A quantitative relationship was observed between testosterone peaks and preceding LH peaks at 14 and 22 weeks of age, but not at 6 weeks. Prolactin secretion profiles of prepubertal (6 weeks) and sexually maturing (14 and 22 weeks) rams were similar and levels fluctuated markedly at each age. A stress-induced elevation of plasma LH levels was observed in approximately 70% of animals sampled in both experiments, while the occurrence of similar elevations of plasma prolactin levels due to stressful procedures was confirmed.
650 $aEndocrinology
650 $aHormones
650 $aPhysiology
650 $aProlactin
650 $aReproduction
650 $aSheep
650 $aTestosterone
650 $aEndocrinologia
650 $aFisiologia
650 $aOvino
650 $aReprodução
700 1 $aLAPWOOD, K. R.
773 $tBiology of Reproduction$gv. 20, n. 4, p. 965-970, 1979.
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| 1. |  | SANTOS, A. R. dos; KUHN, C. E. S.; REIS, F. A. G. V.; CANIL, K.; FIGUEIRA, R. M.; PEREIRA FILHO, A. J.; NASCIMENTO, M. A. L. do; HOFF, R. Geologia de engenharia, riscos ambientais e planejamento territorial. In:REIS, F. A. G. V.; KUHN, C. E. S.; FIGUEIRA, R. M.; VIERO, A. P.(Ed.). Geologia na construção e desenvolvimento sustentável do Brasil. São Paulo: FEBRAGEO, 2019. p. 124-146.| Tipo: Capítulo em Livro Técnico-Científico |
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