Meyers-Brown Geraldine A, McCue Patrick M, Troedsson Mats H T, Klein Claudia, Zent Walter, Ferris Ryan A, Lindholm Alicia R G, Scofield David B, Claes Anthony N, Morganti Monica, Colgin Mark A, Wetzel Robert L, Peters Andrew R, Roser Janet F
Department of Animal Science, University of California, Davis, California, USA.
Theriogenology. 2013 Sep 15;80(5):456-62. doi: 10.1016/j.theriogenology.2013.04.029. Epub 2013 Jun 13.
Traditionally, mares are put under artificial lights to advance the first ovulation of the year. The aim of the present study was to determine the efficacy of recombinant equine FSH (reFSH) in stimulating follicular development and advancing the first ovulation of the year in seasonally anestrous mares compared with anestrous mares given a placebo. Both groups of mares were housed under ambient light conditions. Sixty deep anestrous mares of light horse breeds (follicular diameters ≤ 20 mm in diameter and progesterone <1 ng/mL) were maintained under a natural photoperiod at three different sites: University of California, Davis, Colorado State University, and University of Kentucky Gluck Centre. Twenty mares at each site were randomly allocated to receive either 0.65 mg of reFSH (group A: treatment; n = 10) or a placebo (group B: control; n = 10) twice daily by im beginning on January 31. Treatment continued until one or more preovulatory follicles developed or up to a maximum of 15 days. Randomized treatments were blinded. Follicular development was closely monitored by transrectal ultrasonography. When the largest follicle reached ≥ 35 mm in diameter, reFSH treatment was discontinued and an injection of 2500 international units of hCG was administered iv 36 hours later to induce ovulation. Jugular blood samples were collected daily from all mares at University of California, Davis, and processed for LH, FSH, progesterone, estradiol-17β, and immunoreactive-inhibin by RIA. All 30 mares receiving reFSH (group A) developed follicles ≥ 35 mm within 7.4 ± 1.6 days of treatment. Twenty-three of the 30 reFSH-treated mares (group A) ovulated within 72 hours after hCG administration. In contrast, mares in group B (placebo, control) did not exhibit significant follicular development and none ovulated within the 15-day observation period. Mares in group A had significantly higher plasma levels of FSH, estradiol-17β, and immunoreactive-inhibin during treatment but did not exhibit a preovulatory LH surge. Mares administered reFSH returned to anestrus and spontaneously ovulated at a similar calendar date as control mares. These data indicate that reFSH was effective in stimulating the development of ovarian follicles and advancing the first ovulation of the year in seasonally anestrous mares under ambient lights but was not successful in inducing continued cyclicity.
传统上，母马会被置于人造光下以提前一年中的首次排卵。本研究的目的是确定重组马促卵泡素（reFSH）与给予安慰剂的乏情母马相比，在刺激季节性乏情母马卵泡发育和提前一年中的首次排卵方面的效果。两组母马均饲养在自然光照条件下。60匹轻型马品种的深度乏情母马（卵泡直径≤20毫米且孕酮<1纳克/毫升）在三个不同地点：加利福尼亚大学戴维斯分校、科罗拉多州立大学和肯塔基大学格鲁克中心，在自然光照周期下饲养。每个地点的20匹母马被随机分配，从1月31日开始每天两次通过肌肉注射接受0.65毫克reFSH（A组：治疗组；n = 10）或安慰剂（B组：对照组；n = 10）。治疗持续到一个或多个排卵前卵泡发育或最长持续15天。随机治疗是盲法的。通过经直肠超声密切监测卵泡发育。当最大卵泡直径达到≥35毫米时，停止reFSH治疗，并在36小时后静脉注射2500国际单位的hCG以诱导排卵。每天从加利福尼亚大学戴维斯分校的所有母马采集颈静脉血样，并通过放射免疫分析法检测促黄体生成素（LH）、促卵泡素（FSH）、孕酮、雌二醇-17β和免疫反应性抑制素。所有30匹接受reFSH的母马（A组）在治疗的7.4±1.6天内卵泡直径达到≥35毫米。30匹接受reFSH治疗的母马（A组）中有23匹在注射hCG后72小时内排卵。相比之下，B组（安慰剂，对照组）的母马未表现出明显的卵泡发育，在15天观察期内无一排卵。A组母马在治疗期间血浆FSH、雌二醇-17β和免疫反应性抑制素水平显著较高，但未出现排卵前LH高峰。接受reFSH治疗的母马恢复到乏情状态，并在与对照母马相似的日历日期自发排卵。这些数据表明，reFSH在自然光照下能有效刺激季节性乏情母马卵巢卵泡发育并提前一年中的首次排卵，但未能成功诱导持续的发情周期。
