220ENDOCRINE AND OVARIAN FUNCTION AFTER GNRH ANTAGONIST TREATMENTS IN GOATS
| Autor: | J. Santiago Moreno, Rosa M. Garcia-Garcia, Alan S. McNeilly, Antonio López-Sebastián, Antonio Gonzalez-Bulnes, Carlos José Hoff de Souza |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
medicine.medical_specialty
media_common.quotation_subject Theriogenology Reproductive technology Biology Oogenesis Endocrinology Reproductive Medicine Internal medicine Follicular phase Genetics medicine Endocrine system Animal Science and Zoology Folliculogenesis Molecular Biology Spermatogenesis Ovulation Developmental Biology Biotechnology media_common |
| Zdroj: | Reproduction, Fertility and Development. 16:231 |
| ISSN: | 1031-3613 |
| Popis: | In goats, as in other mammals, the use of treatment with GnRH antagonists (GnRHa) inhibits gonadotrophin secretion, causing a suppression of the growth of large ovarian follicles. Thus, GnRHa treatment could be useful to decrease the effects of dominant follicles prior to ovarian stimulation, increasing the number of gonadotrophin-responsive follicles at the start of FSH treatments and improving the ovarian response in terms of transferable embryos. However, in goats, the beneficial effects of this treatment is annulled by a high number of unfertilised ova and degenerated embryos (2003, Cognie et al., Theriogenology 59, 171–188), which suggests deficiencies in oocyte developmental competence per se or induced by endocrine or follicular alterations during the peri-ovulatory period. We have tested whether these failures can be related to a prolongation of gonadotrophin down-regulation and/or alterations in follicular function after cessation of the antagonist, during the period of administration of the superovulatory treatment, around 4 days after the end of GnRHa treatment. A total of 15 does received 45-mg FGA intravaginal sponges (Chronogest®, Intervet Int, H), the first group of 10 females were treated with daily injections of 0.5mg of the GnRHa Teverelix (Antarelix™, Zentaris, G) for 6 days from Day 5 of sponge insertion, while five does acted as controls receiving saline. Endocrine and ovarian function were monitored daily from Day −5 to Day 4 (Day 0=day of last GnRHa injection). Pituitary activity was determined by measuring plasma FSH and LH, and follicular activity by ultrasonographic monitoring of all >2mm follicles and by assessing plasma inhibin A levels. During GnRH antagonist treatment, the mean plasma LH concentration was lower in treated than control goats (0.5±0.2 v. 0.7±0.5ng/mL, P4mm in size (5.0±0.3 v. 6.8±0.5, P4mm in size and the secretion of inhibin A remained lower in treated goats (3.9±0.3 follicles and 84.4±7.0pg/mL v. 5.4±0.5 follicles, P |
| Databáze: | OpenAIRE |
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