Development of a practical means for pheromonal manipulation of reproduction.

本研究的目的是收集必要的信息，为开发利用天然产生的信息素来人工操纵家养反刍动物生殖内分泌功能的可行措施提供必要的信息。本研究的重点是负责“雄性效应”的信息素(S)，这种现象被称为雄性信息素在季节性无发情母羊和母羊中诱导的卵巢重新激活。作为方法的第一步，建立了一套特异的生物检测系统。即通过记录多单位活动(MUA)来监测清醒去卵巢山羊下丘脑GnRH脉冲发生器活动的电生理表现。通过观察去卵巢山羊在16L8D光照条件下，是否暴露于被测物质是否导致GnRH脉冲产生器活性加速，来评估是否存在引子信息素活性。通过这一特异的生物测定，我们能够证明从头和/或颈部获取的毛发或皮肤样本的乙醚提取物具有刺激下丘脑GnRH脉冲产生器的强信息素活性。由此确定的信息素物质也被证明是在雄性山羊的皮脂腺中依赖雄激素产生的，这些挥发性信息素的相对分子质量将小于400。目前的结果有力地表明，导致绵羊和山羊雄性效应的信息素(S)是一种与脂肪酸或类固醇递送物质有很大相似化学特征的分子。这项研究中获得的信息对于进一步纯化哺乳动物信息素似乎是必不可少的。

The aim of this study was to collect necessary information for the development of feasible measures of artificially manipulating reproductive endocrine function of domestic ruminants by using their naturally-produced pheromones.We focused on the pheromone (s) responsible for the "male effect", a phenomenon known as the ovarian reactivation induced by male pheromones in seasonally anestrous ewes and does. As the first step of approach, a specific bioassay system was established. Namely, the electrophysiological manifestation of the hypothalamic GnRH pulse generator activity was monitored from conscious ovariectomized goats by recording the multiple unit activity (MUA). The existence of primer pheromone activity was assessed based on the observation whether of not the exposure to tested-material resulted in an acceleration of the GnRH pulse generator activity in ovariectomized goats, which had been primed with estradiol and kept under 16L8D photoperiod.By means of this specific bioassay we were able to show that ether extracts from hair or skin samples obtained from head and/or neck regions possess strong pheromone activity in terms of stimulating the hypothalamic GnRH pulse generator. Thus identified pheromonal substances were also shown to be produced androgen dependently at the sebaceous glands of male goats, and the molecular weight of these volatile pheromones would be less than 400. The present results strongly suggest that pheromone (s) responsible for the male effect in sheep and goats is a molecule which largely shares chemical characteristics with either fatty acids or steroid delivertives. The information obtained in this study appears essential for further purifying mammalian pheromones.