McGrath Briony M, Scott Christopher J, Wynn Peter C, Loy Jaymie, Norman Scott T
School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.
School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.
Theriogenology. 2016 Oct 1;86(6):1566-1572. doi: 10.1016/j.theriogenology.2016.05.016. Epub 2016 May 25.
Managing the return to regular cyclicity after the winter anestrous period in the mare has been a challenge for the equine breeding industry. Specifically, efforts have been made to shift or shorten the vernal transition period and to have it followed by a predictable first ovulation at the commencement of the breeding season. Intravenous administration of kisspeptin is known to stimulate an LH response in both reproductively active and inactive mares. This study examined the effects of a constant rate infusion (CRI) of kisspeptin on mares during vernal transition. Mares were given a 30 hours infusion of kisspeptin at a low and high rate (66 nmol [88 μg] and 100 nmol [130 μg] per hour, respectively) or saline, and the LH and follicular response tracked. Plasma samples were collected every 15 minutes for the first 6 hours to determine if there is an acute effect of kisspeptin infusion on LH secretion. Plasma samples were then collected every 3 hours for a total of 72 hours to examine the ability of kisspeptin to stimulate an LH surge. A CRI of kisspeptin increased LH secretion in these mares but was not able to stimulate an LH surge. To examine the effect of kisspeptin on ovarian activity, follicular measurements were collected ultrasonographically until ovulation occurred or the follicles regressed. CRI of kisspeptin at these rates was unable to induce ovulation earlier than controls.
在母马冬季乏情期后恢复正常周期性发情，一直是马繁育行业面临的一项挑战。具体而言，人们一直在努力改变或缩短春季过渡期，并使其在繁殖季节开始时能紧接着出现可预测的首次排卵。已知静脉注射 kisspeptin 可刺激处于繁殖活跃期和非活跃期的母马出现促黄体生成素（LH）反应。本研究考察了在春季过渡期持续输注（CRI）kisspeptin 对母马的影响。给母马分别以低速率和高速率（分别为每小时 66 nmol [88 μg] 和 100 nmol [130 μg]）输注 kisspeptin 30 小时或输注生理盐水，并追踪 LH 和卵泡反应。在最初 6 小时内每 15 分钟采集一次血浆样本，以确定 kisspeptin 输注对 LH 分泌是否有急性效应。然后每 3 小时采集一次血浆样本，共采集 72 小时，以检测 kisspeptin 刺激 LH 峰的能力。kisspeptin 的 CRI 增加了这些母马的 LH 分泌，但未能刺激 LH 峰。为了考察 kisspeptin 对卵巢活动的影响，在超声检查下采集卵泡测量数据，直至排卵发生或卵泡退化。以这些速率进行 kisspeptin 的 CRI 并不能比对照组更早地诱导排卵。
