Effects of a Gonadotropin-Releasing Hormone Agonist Implant on Reproduction in a Male Marsupial, Macropus eugenii1
| Autor: | Marilyn B. Renfree, Desmond W. Cooper, Geoff Shaw, Douglas C. Eckery, Catherine A. Herbert, T.E. Trigg |
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| Rok vydání: | 2004 |
| Předmět: |
Agonist
medicine.medical_specialty medicine.drug_class Deslorelin Cell Biology General Medicine Gonadotropin-releasing hormone Biology biology.organism_classification chemistry.chemical_compound Tammar wallaby Endocrinology Reproductive Medicine chemistry Desensitization (telecommunications) Internal medicine Gonadotropin-releasing hormone agonist medicine Luteinizing hormone Testosterone |
| Zdroj: | Biology of Reproduction. 70:1836-1842 |
| ISSN: | 1529-7268 0006-3363 |
| DOI: | 10.1095/biolreprod.103.025122 |
| Popis: | This study evaluated the potential of slow-release GnRH agonist (deslorelin) implants to inhibit reproductive function in the male tammar wallaby. The specific aim was to measure the effects of graded dosages of deslorelin on testes size and plasma LH and testosterone concentrations. Adult male tammar wallabies were assigned to four groups (n = 6 per group) and received the following treatment: control, placebo implant; low dose, 5 mg deslorelin; medium dose, 10 mg; high dose, 20 mg. All dosages of deslorelin induced acute increases (P 0.05). These results suggest that the male tammar wallaby is resistant to the contraceptive effects of chronic GnRH agonist treatment. Despite the maintenance of testosterone secretion, the majority of male tammars (10 of 17) failed to respond to a GnRH challenge with a release of LH between Days 186 and 197 of treatment. The failure of animals to respond to exogenous GnRH suggests a direct effect of deslorelin on the pituitary, resulting in a level of desensitization that was sufficient to inhibit a LH surge but insufficient to inhibit basal LH secretion. The variation between animals is believed to result from earlier recovery of some individuals, in particular those that received a lower dose, or individual resistance to the desensitization process. |
| Databáze: | OpenAIRE |
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