219EFFECTS OF GROWTH HORMONE AND GNRH ANTAGONISTS ON FOLLICULAR AND OOCYTE DEVELOPMENT IN SHEEP
| Autor: | Teresa Encinas, Rosa M. Garcia-Garcia, P. Gonzalez-Añover, Julián Santiago-Moreno, M.J. Cocero, Antonio Gonzalez-Bulnes, Antonio López-Sebastián, Almudena Veiga-Lopez |
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| Rok vydání: | 2004 |
| Předmět: |
medicine.medical_specialty
education.field_of_study Theriogenology Population Embryo culture Reproductive technology Biology Oogenesis Endocrinology Reproductive Medicine Internal medicine Follicular phase Genetics medicine Animal Science and Zoology Folliculogenesis education Molecular Biology Spermatogenesis Developmental Biology Biotechnology |
| Zdroj: | Reproduction, Fertility and Development. 16:231 |
| ISSN: | 1031-3613 |
| Popis: | Embryo output in sheep is increased when superovulatory FSH treatments are started in the presence of a high number of small follicles (2–3mm in size) and in absence of large follicles (>6mm, Gonzalez-Bulnes et al., 2002. Theriogenology, 57, 1263–1272). Administration of GnRH antagonists (GnRHa) suppresses large follicles (Cognie et al., 2003. Theriogenology, 59, 171–188), whereas the use of growth hormone (GH) would increase the number of small follicles (Campbell et al., 1995. J Reprod Fertil Suppl, 49, 335–350). Our aim was to evaluate the usefulness of pre-treatments with GH or GH plus GnRH antagonists for sheep embryo production. First, we studied the effects on follicular population by serial ultrasonographies. Thereafter, we determined whether such treatments can affect oocyte developmental competence. In a first trial, a total of 18 Manchega ewes were treated with intravaginal FGA sponges (Chronogest®, Intervet Int., H) during breeding season (beginning of April). Six animals received daily i.m. doses of 15mg of ovine GH (Tuenre, GA) for 6 days, while six females received GH plus two s.c. doses of 1.5mg of GnRHa (Antarelix™, Zentaris, G) on Days 0 and 3 of GH treatment, and six ewes acted as controls receiving saline. Number of follicles >2mm, determined by daily transrectal ultrasonography, increased to reach significant differences on Day 4 in sheep treated with GH/GnRHa (22.7±0.8 v. 16.7±0.5, P |
| Databáze: | OpenAIRE |
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