EFFECT OF ASYMMETRICAL REDUCTIONS OF PHOTOPERIOD ON PINEAL MELATONIN, LOCOMOTOR-ACTIVITY AND GONADAL CONDITION OF MALE SYRIAN-HAMSTERS
EFFECT OF ASYMMETRICAL REDUCTIONS OF PHOTOPERIOD ON PINEAL MELATONIN, LOCOMOTOR-ACTIVITY AND GONADAL CONDITION OF MALE SYRIAN-HAMSTERS
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DOI：
10.1677/joe.0.1140221
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发表时间：
1987-08-01
影响因子：
4
通讯作者：
HERBERT, J
中科院分区：
文献类型：
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作者：
HASTINGS, MH;WALKER, AP;HERBERT, J
该研究通过比较松果体中两种明显的昼夜节律、运动活动和褪黑激素合成的关系，比较它们对光周期不对称减少的反应。将雄性叙利亚仓鼠从长日照转移到短日照会导致运动活动持续时间和褪黑激素合成时间的增加。在重新夹带的过程中，两种节律保持稳定的相位关系，并且切换的方向不影响减压速率或短日照8周后建立的最终相位关系。活动节律的减压不受松果体切除术的影响。暴露于短光周期会导致性腺退化，从而导致血清睾酮水平从 10 nmol/l 下降至 < 1 nmol/l。光周期开关的方向不影响性腺退化的时间过程。这些数据证明了光周期对松果体产生褪黑激素的夜间峰值持续时间的重要影响，并且还证明了这种效应是昼夜节律系统更广泛反应的一个例子。性质相似的信号控制着运动活动和褪黑激素的合成，尽管这种共同机制的神经基础尚不清楚。
The study investigated the relationship of two overt circadian rhythms, locomotor activity and melatonin synthesis in the pineal gland, by comparing their responses to asymmetrical reductions in photoperiod. Transfer of male Syrian hamsters from long to short daylengths led to an increase in the duration of both locomotor activity and the period of melatonin synthesis. Over the course of re-entrainment, the two rhythms were held in a stable phase relationship, and the direction of the switch did not influence the rate of decompression or the final phase relationships established after 8 weeks in short daylengths. Decompression of the activity rhythm was not influenced by pinealectomy. Exposure to short photoperiods caused gonadal regression and a consequent decline in serum testosterone levels from 10 to < 1 nmol/l. The direction of the photoperiodic switch did not affect the time-course of gonadal regression. These data demonstrate the important influence of photoperiod upon the duration of the nocturnal peak of melatonin production by the pineal and also demonstrate that this effect is one example of a more widespread response of the circadian system. A qualitatively similar signal controls both locomotor activity and melatonin synthesis, although the neural basis of this common mechanism is unclear.