Stieglitz A, Steinlechner S, Ruf T, Heldmaier G
Department of Biology/Zoology, Philipps-University, Marburg, Germany.
J Comp Physiol A. 1991 May;168(5):599-603. doi: 10.1007/BF00215082.
In the Djungarian hamster seasonal acclimatization is primarily controlled by photoperiod, but exposure to low ambient temperature amplifies the intensity and duration of short day-induced winter adaptations. The aim of this study was to test, whether the pineal gland is involved in integrating both environmental cues. Exposure of hamsters to cold (0 degrees C) reduces the sensitivity of the pineal gland to light at night and prevents inactivation of N-acetyltransferase (NAT). The parallel time course of NAT activity and plasma norepinephrine content suggests that circulating catecholamines may stimulate melatonin synthesis under cold load.
在西伯利亚仓鼠中，季节性适应主要受光周期控制，但暴露于低环境温度会增强短日照诱导的冬季适应性的强度和持续时间。本研究的目的是测试松果体是否参与整合这两种环境信号。将仓鼠暴露于寒冷环境（0摄氏度）会降低松果体在夜间对光的敏感性，并阻止N-乙酰转移酶（NAT）失活。NAT活性和血浆去甲肾上腺素含量的平行时间进程表明，循环中的儿茶酚胺可能在冷负荷下刺激褪黑素的合成。
