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Photoperiodic regulation of pineal and plasma melatonin levels in intact or pinealectomized chickens.

完整或松果体切除鸡的松果体和血浆褪黑激素水平的光周期调节。

基本信息

批准号：
60480078
负责人：
TANABE Yuichi
金额：
$ 4.42万
依托单位：
Gifu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

项目摘要

Photoperiodic regulation of plasma melatonin levels in intact or pinealectomized chicken was studied to elucidate the role of pineal gland in circadian rhythm of the chicken. Under a 14L:10D photoperiod, a circadian rhythm in plasma melatonin disappearred in pinealectomized chickens (pinealectomized at 1 day of age) at 16, 29, 65 and 100 days of age, whereas the rhythm was always observed either in intact or sham-operated chickens at corresponding ages. When 14-day-old cockerels and pullets, which had been kept under a 12D:12L photoperiod, were shifted to a 12L:12D photoperiod, a circadian plasma melatonin rhythm disappered in the first dark period, but resumed in the second dark period. When the cockerels which had been kept under a 12L:12D photoperiod, were shifted to a 12D:12L photoperiod, the first nocturnal rise of plasma melatonin appered in the second dark period in a reduced magnitude, and in the third dark period in a greater magnitude. When 82-day-old pullets, which had been kept under a 12D:12L photoperiod. were shifted to a 12L:12D photopriod, plasma melatonin rise was observed in the first dark time. Similar results were observed in the photoperiodic shift in 450-day-old pullets. These results indicate the decrease in the strength of memory for circadian light-dark rhythms with advancing age in the chicken.

为阐明松果体在鸡昼夜节律中的作用，研究了光周期对松果体完整和去松果体鸡血浆褪黑激素水平的调节。在14L：10D光周期下，去松果体鸡（1日龄去松果体）血浆褪黑素的昼夜节律在16、29、65和100日龄时消失，而在相应日龄的正常鸡和假手术鸡中均观察到这种节律。当14日龄的公鸡和母鸡，一直保持在12D：12L的光周期下，转移到12L：12D的光周期，昼夜血浆褪黑激素节律消失，在第一个黑暗时期，但在第二个黑暗时期恢复。当公鸡一直保持在12L：12D的光周期下，转移到12D：12L的光周期，第一夜血浆褪黑激素的上升出现在第二个黑暗时期在一个减少的幅度，并在第三个黑暗时期在一个较大的幅度。当82日龄母鸡处于12 D：12 L光周期下时。转移到12L：12D的对数周期，在第一个黑暗时间观察到血浆褪黑激素升高。在450日龄雏鸡的光周期变化中也观察到类似的结果。这些结果表明，随着年龄的增长，鸡的昼夜光暗节律的记忆强度下降。