A role for melatonin as a timekeeping hormone in the ewe.
A role for melatonin as a timekeeping hormone in the ewe.
复制标题
褪黑激素在母羊中作为计时激素的作用。
DOI：
--
复制
发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Karsch Fj
中科院分区：
文献类型：
--
作者：
Karsch Fj
本报告的重点是褪黑激素的作用，以及它如何在母羊的季节性繁殖过程中作为一种计时激素。在这种短日繁殖动物中，褪黑素的24小时分泌特征非常容易受到光周期的调节。褪黑素模式性质的改变反过来又会引起下丘脑/垂体活动的变化以及雌二醇抑制促性腺激素分泌的能力的变化。后一种变化驱动了动情周期的季节性发生。特别强调褪黑素如何编码母羊的白昼长度。对两种当前理论模型（夜间褪黑激素上升的阶段和持续时间）的证据进行了评估，并强调了褪黑激素模式变化的重要性。显然，对褪黑激素信号作出反应并将其转化为下丘脑活动变化的系统是非常复杂的。然而，坚实的概念开始出现，丰富的问题继续出现，使这成为未来研究的肥沃领域。
: This report has focused on the actions of melatonin and how it serves as a timekeeping hormone in the seasonal reproductive process of the ewe. In this short-day breeder, the characteristics of the 24-hour secretory profile of melatonin are highly susceptible to regulation by photoperiod. Changes in the nature of the melatonin pattern, in turn, provoke changes in hypothalamic/pituitary activity and the ability of estradiol to inhibit gonadotropin secretion. These latter changes drive the seasonal occurrence of estrous cycles. Special emphasis was placed on how melatonin codes for daylength in the ewe. Evidence was evaluated for two current theoretical models (phase and duration of the nighttime melatonin rise) and the importance of change in the melatonin pattern was stressed. Clearly, the systems which respond to the melatonin signal and convert it into changes in hypothalamic activity are highly complex. Nevertheless, solid concepts are beginning to emerge and rich questions continue to arise, making this a fertile area for future research.