Increase of plasma eCG binding rate after administration of repeated high dose of eCG to cows
| Autor: | Edmond M. Mcnamara, Jean-François Beckers, Pierre Drion, Rudy De Roover, J. Y. Houtain, Benoit Remy, José Sulon |
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| Rok vydání: | 2001 |
| Předmět: |
Embryology
medicine.medical_specialty Gonadotropins Equine Chorionic gonadotrophin Dose-Response Relationship Immunologic Medicine (miscellaneous) Antibodies Drug Administration Schedule Iodine Radioisotopes Immune system Ovarian Follicle Internal medicine Follicular phase High doses Animals Medicine Statistical analysis biology business.industry Immune Sera Kinetics Endocrinology Reproductive Medicine biology.protein Cattle Female Animal Science and Zoology Antibody business After treatment Developmental Biology Food Science Hormone |
| Zdroj: | Reproduction Nutrition Development. 41:207-215 |
| ISSN: | 1297-9708 0926-5287 |
| Popis: | Equine chorionic gonadotrophin (eCG) is still used to promote follicular growth in cattle and, more recently with an increased frequency of administration, in ovum pick-up protocols. The aim of this experiment was to verify the possible effect of high frequency of administration on the immune response to eCG. The profiles of eCG binding rate, in the blood of two groups (A, B) of 4 primiparous cross breed beef cows (3-3.5 years old) submitted weekly for 5 to 10 weeks to repeated high doses (1000-2000 IU) of equine chorionic gonadotrophin, are presented in this paper. A sensitive radiometric method was used to detect antibodies in plasma. The profiles clearly indicated a marked increase of eCG binding rate after 3 to 5 injections of the exogenous hormone to the females. The statistical analysis of the results established that treatments induced a significant increase (P0.01) in binding rates after 6 and 3 injections in group A and B respectively. These binding rates remained elevated for at least 1 week following the last injection and decreased afterwards. The values of plasma binding rates following repeated eCG administration differed significantly between groups (0.90+/-1.04 and 1.04+/-0.11 for groups A and B before treatment versus 11.77+/-0.92, 6.70+/-0.85 for groups A and B after treatment, P0.01) and from one cow to another (P0.01) with some cows presenting no significant immune response while others were more reactive against the hormone (at least 3 injections). |
| Databáze: | OpenAIRE |
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