Data/hora: 28/05/2024 07:09:09

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: | --
Registro original: | Embrapa Caprinos e Ovinos (CNPC)
Exemplares: | CNPC - (5060-1) - ADC - AP - -- -  -  - 1999.00000 - DIS