Florant G L, Rivera M L, Lawrence A K, Tamarkin L
Am J Physiol. 1984 Dec;247(6 Pt 2):R1062-6. doi: 10.1152/ajpregu.1984.247.6.R1062.
Plasma melatonin concentrations were measured throughout bouts of hibernation in marmots maintained in a short photoperiod (light-dark 8:16) and ambient temperature of 5 or 15 degrees C. Melatonin concentration was also measured in two animals maintained in constant darkness. As an animal entered hibernation, plasma melatonin concentrations dropped to basal levels when body temperature reached 25 degrees C, and they remained low until arousal. During deep hibernation plasma melatonin values did not vary significantly (P greater than 0.05) with respect to time of day or different ambient temperatures. With nocturnal arousal plasma melatonin levels were similar to euthermic night values. Lack of a plasma melatonin rhythm during hibernation suggests that the pineal gland is not temperature compensated during hibernation, and due to the low tissue temperature of the pineal the circadian pacemaker driving melatonin secretion is incapable of stimulating a rhythm.
在短光照周期（光照 - 黑暗时间为8:16）且环境温度为5或15摄氏度的条件下，对土拨鼠冬眠期间的血浆褪黑素浓度进行了全程测量。还对处于持续黑暗环境中的两只动物的褪黑素浓度进行了测量。当动物进入冬眠状态，体温达到25摄氏度时，血浆褪黑素浓度降至基础水平，并在苏醒前一直保持在低水平。在深度冬眠期间，血浆褪黑素值在一天中的不同时间或不同环境温度下均无显著变化（P大于0.05）。夜间苏醒时，血浆褪黑素水平与正常体温夜间值相似。冬眠期间血浆褪黑素节律的缺失表明，松果体在冬眠期间没有温度补偿机制，并且由于松果体组织温度较低，驱动褪黑素分泌的昼夜节律起搏器无法刺激节律产生。
