Registro Completo |
Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
Data corrente: |
04/10/1999 |
Data da última atualização: |
04/10/1999 |
Autoria: |
KHALID, M.; IJAZ, A.; HARESIGN, W. |
Título: |
Response of LH to long-term pulsatile and continous infusions of GNRH in ovariectomized, estradiol-17 B implanted ewes during seasonal anoestrous. |
Ano de publicação: |
1999 |
Fonte/Imprenta: |
Assiut Veterinary Medical Journal, v.41, n.81, p.253-264, 1999. |
Idioma: |
Inglês |
Conteúdo: |
Pituitary LH responses to long-term pulsatile and continous infusion of GnRH were monitored in estradiol-17 B-implanted ovariectomized ewes during seasonal anoestrous(April and May). The experiment was performed in 2 replicates(8 ewes per replicate). Half of the animals in each replicate were infused continuously with GnRH(175ng/h), while the other half were given a pulsatile injection of 350ng GnRH every 2h for a period of 20 days. GnRH administration was carried out via indwelling jugular vein catheter. Blood samples for LH determination were collected at 15min intervals, from 6h before until 24h after the start of treatment, and then at 8h bleed on day 20 was immediately followed by a 12h bleed once the treatment had ended. Before the start of GnRH treatment, plasma LH concentrations rose immediately in infused animals. However, after an initial significant elevation on day1, LH values were not different from mean pre-treatment concentrations for the rest of the treatment period. In contrast, injected ewes(350ng GnRH) responded to each GnRH injection throughout the 20 day treatment period. The results suggested that the pituitary gland remains responsive to pulsatile but not to continuous GnRH administration for longer time periods. |
Palavras-Chave: |
Anestro; GnRH; LH. |
Thesagro: |
Ovino. |
Categoria do assunto: |
-- |
Marc: |
LEADER 01825naa a2200193 a 4500 001 1518922 005 1999-10-04 008 1999 bl uuuu u00u1 u #d 100 1 $aKHALID, M. 245 $aResponse of LH to long-term pulsatile and continous infusions of GNRH in ovariectomized, estradiol-17 B implanted ewes during seasonal anoestrous. 260 $c1999 520 $aPituitary LH responses to long-term pulsatile and continous infusion of GnRH were monitored in estradiol-17 B-implanted ovariectomized ewes during seasonal anoestrous(April and May). The experiment was performed in 2 replicates(8 ewes per replicate). Half of the animals in each replicate were infused continuously with GnRH(175ng/h), while the other half were given a pulsatile injection of 350ng GnRH every 2h for a period of 20 days. GnRH administration was carried out via indwelling jugular vein catheter. Blood samples for LH determination were collected at 15min intervals, from 6h before until 24h after the start of treatment, and then at 8h bleed on day 20 was immediately followed by a 12h bleed once the treatment had ended. Before the start of GnRH treatment, plasma LH concentrations rose immediately in infused animals. However, after an initial significant elevation on day1, LH values were not different from mean pre-treatment concentrations for the rest of the treatment period. In contrast, injected ewes(350ng GnRH) responded to each GnRH injection throughout the 20 day treatment period. The results suggested that the pituitary gland remains responsive to pulsatile but not to continuous GnRH administration for longer time periods. 650 $aOvino 653 $aAnestro 653 $aGnRH 653 $aLH 700 1 $aIJAZ, A. 700 1 $aHARESIGN, W. 773 $tAssiut Veterinary Medical Journal$gv.41, n.81, p.253-264, 1999.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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