Hasegawa M, Ebihara S
Department of Animal Physiology, Faculty of Agriculture, Nagoya University, Japan.
Neurosci Lett. 1992 Dec 14;148(1-2):89-92. doi: 10.1016/0304-3940(92)90811-k.
Circadian rhythms of pineal melatonin release were measured in freely moving pigeons (Columba livia) by in vivo microdialysis. The birds were placed in light-dark cycles with 12 h of light and 12 h of darkness (LD 12:12) or continuous dim light (LLdim) after LD 12:12. Although the level of melatonin was various, daily changes of melatonin with higher levels during the dark and lower levels during the light were observed in all of the birds examined. The daily changes of melatonin persisted in LLdim, indicating circadian nature of pineal melatonin release. Moreover pineal melatonin release was inhibited by acute exposure of light during the dark. These results indicate that microdialysis is useful for studying circadian pineal melatonin rhythms of birds.
通过体内微透析法测定了自由活动的鸽子（家鸽）松果体褪黑素释放的昼夜节律。将这些鸽子置于12小时光照和12小时黑暗的光暗循环（LD 12:12）中，或在LD 12:12后置于持续弱光（LLdim）环境中。尽管褪黑素水平各不相同，但在所有检测的鸽子中均观察到褪黑素的每日变化，黑暗期间水平较高，光照期间水平较低。褪黑素的每日变化在LLdim中持续存在，表明松果体褪黑素释放具有昼夜节律性。此外，在黑暗期间急性暴露于光照会抑制松果体褪黑素的释放。这些结果表明，微透析法对于研究鸟类松果体褪黑素的昼夜节律是有用的。
