Edmonds K E, Rollag M D, Stetson M H
Physiology and Anatomy Section, School of Life and Health Sciences, University of Delaware, Newark 19716, USA.
J Pineal Res. 1995 Apr;18(3):148-53. doi: 10.1111/j.1600-079x.1995.tb00153.x.
Pineal melatonin content was examined under four different photoperiods (10L:14D, 12L:12D, 14L:10D, and 16L:8D) in adult female rice rats (Experiment 1). Pineal melatonin was basal during the light and increased beginning 1 hr after lights off. Within 2 hr after lights off, melatonin increased to levels that were maintained throughout the dark period. In all but one photoperiod (10L:14D), melatonin remained elevated prior to light onset and decreased markedly within one hour after lights on. In addition, the duration of pineal melatonin was inversely related to the length of the photoperiod. In Experiment 2, the time course of pineal melatonin content on 16L:8D was examined every 20 min during the first hour after lights off and the first hour after lights on. Melatonin content increased gradually during the first hour and decreased markedly within 20 min after lights on. These data show that pineal melatonin in female rice rats is regulated by photoperiod.
在成年雌性稻鼠中（实验1），在四种不同光周期（10小时光照：14小时黑暗、12小时光照：12小时黑暗、14小时光照：10小时黑暗和16小时光照：8小时黑暗）下检测松果体褪黑素含量。松果体褪黑素在光照期间处于基础水平，在熄灯后1小时开始增加。在熄灯后2小时内，褪黑素增加到在整个黑暗期维持的水平。除了一个光周期（10小时光照：14小时黑暗）外，在光照开始前褪黑素保持升高，在开灯后1小时内显著下降。此外，松果体褪黑素的持续时间与光周期长度呈负相关。在实验2中，在熄灯后第一小时和开灯后第一小时内每隔20分钟检测一次16小时光照：8小时黑暗条件下松果体褪黑素含量的时间进程。褪黑素含量在第一小时内逐渐增加，在开灯后20分钟内显著下降。这些数据表明雌性稻鼠的松果体褪黑素受光周期调节。
