Baker D L, Wild M A, Conner M M, Ravivarapu H B, Dunn R L, Nett T M
Colorado Division of Wildlife, Wildlife Research Center, Fort Collins 80526, USA.
Reprod Suppl. 2002;60:155-67.
Fertility control offers a potential alternative to traditional methods for regulating the growth of overabundant wild ungulate populations. However, current technology is limited due to practical treatment application, undesirable side-effects and economic considerations. A promising non-steroidal, non-immunological approach to contraception involves the use of a potent GnRH agonist. Two experiments were conducted to evaluate the effectiveness of a GnRH agonist (leuprolide) for controlling fertility in captive female wapiti and to assess physiological and behavioural side-effects of the treatment. In Expt 1, the optimum dose of agonist treatment was determined by measuring serum LH response of eight female wapiti to four formulations of leuprolide (0, 45, 90 and 180 mg) administered as a subcutaneous (s.c.) bioimplant. In Expt 2, the effects of leuprolide on wapiti pregnancy rates, duration of suppression of serum LH and progesterone secretion, and short-term behavioural and physiological side-effects were evaluated. All concentrations of leuprolide in Expt 1 were equally effective in reducing serum LH to non-detectable values throughout the 130 day trial. In Expt 2, leuprolide administered before the breeding season was 100% effective at preventing pregnancy in treated females. Serum LH and progesterone were reduced to baseline values by day 92 and remained at this concentration for 195-251 days after treatment, and returned to pretreatment concentrations in the following breeding season. Reproductive behaviour rates were similar for treated and untreated wapiti for all behaviour categories for both the breeding and post-breeding seasons. Haematology and blood chemistry parameters of treated and un-treated females were similar, and seasonal intake and body weight dynamics appeared normal. In conclusion, leuprolide is a safe, effective contraceptive agent and can potentially suppress fertility in female wapiti for one breeding season.
生育控制为调节数量过多的野生有蹄类动物种群增长提供了一种替代传统方法的潜在选择。然而,由于实际治疗应用、不良副作用和经济因素,目前的技术受到限制。一种有前景的非甾体、非免疫避孕方法涉及使用一种强效促性腺激素释放激素(GnRH)激动剂。进行了两项实验,以评估GnRH激动剂(亮丙瑞林)对圈养雌性马鹿生育控制的有效性,并评估该治疗的生理和行为副作用。在实验1中,通过测量8只雌性马鹿对皮下植入的4种亮丙瑞林制剂(0、45、90和180毫克)的血清促黄体生成素(LH)反应,确定激动剂治疗的最佳剂量。在实验2中,评估了亮丙瑞林对马鹿妊娠率、血清LH和孕酮分泌抑制持续时间以及短期行为和生理副作用的影响。在整个130天的试验中,实验1中所有浓度的亮丙瑞林在将血清LH降低到无法检测的值方面同样有效。在实验2中,在繁殖季节前施用亮丙瑞林对治疗的雌性预防妊娠的有效率为100%。血清LH和孕酮在第92天降至基线值,并在治疗后195 - 251天保持在该浓度,在随后的繁殖季节恢复到治疗前浓度。在繁殖季节和繁殖后季节,治疗和未治疗的马鹿在所有行为类别上的生殖行为率相似。治疗和未治疗雌性的血液学和血液化学参数相似,季节性摄入量和体重动态似乎正常。总之,亮丙瑞林是一种安全、有效的避孕剂,有可能在一个繁殖季节抑制雌性马鹿的生育能力。