Ovarian response after a GnRH challenge in seasonally anestrous ewes
نویسندگان
چکیده
منابع مشابه
Improved Methods for the Production of Embryos in Seasonally Anestrous Ewes
In a recent study from our laboratory, a combination of melatonin implants and controlled internal drug release devices increased the number of developing follicles in follicle stimulating hormone-treated anestrous ewes; however, CIDR treatment decreased the rate of in vitro fertilization (IVF). In the current study, effects of alternative CIDR treatments on follicular development and rate of I...
متن کاملOvarian follicular dynamics after cauterization of the dominant follicle in anestrous ewes.
An experiment was conducted to ascertain if follicles could reach ovulatory size after the largest follicle (dominant) has been removed at different times during a progestin treatment in anestrous ewes, and secondly to determine if these new follicles could respond to an hCG-induced ovulation and have similar function as corpora lutea. Mature crossbred sheep (n=44) in anestrous were treated wit...
متن کاملEvidence that dopamine acts via kisspeptin to hold GnRH pulse frequency in check in anestrous ewes.
Recent work has implicated stimulatory kisspeptin neurons in the arcuate nucleus (ARC) as important for seasonal changes in reproductive function in sheep, but earlier studies support a role for inhibitory A15 dopaminergic (DA) neurons in the suppression of GnRH (and LH) pulse frequency in the nonbreeding (anestrous) season. Because A15 neurons project to the ARC, we performed three experiments...
متن کاملThe role of GABA(A) and GABA(B) receptors in the control of GnRH release in anestrous ewes.
The paper reviews data concerning the involvement of GABA(A) and GABA(B) receptors in the control of GnRH secretion in anestrous ewes. Generally, GABA influences the GnRH release through GABA(A) and GABA(B) receptors located on perikaria of the GnRH neurons in the preoptic area (MPOA) or through the influence on beta-endorphinergic and catecholaminergic systems activity in MPOA and in ventromed...
متن کاملEffects of Exposure to Male Goat Hair Extracts on Luteinizing Hormone Secretion and Neuronal Activation in Seasonally Anestrous Ewes
In sheep and goats, exposure of seasonally anestrous females to males or their fleece/hair activates the gonadotropin-releasing hormone (GnRH) pulse generator leading to pulsatile luteinizing hormone (LH) secretion. Pheromones emitted by sexually mature males are thought to play a prominent role in this male effect. In the present study, we first aimed to clarify whether the male goat pheromone...
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ژورنال
عنوان ژورنال: Canadian Journal of Animal Science
سال: 1997
ISSN: 0008-3984,1918-1825
DOI: 10.4141/a97-068