Induction of photosensitivity in neonatal rat pineal gland.
Induction of photosensitivity in neonatal rat pineal gland.
复制标题
新生大鼠松果体光敏性的诱导。
DOI：
10.1073/pnas.210248297
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发表时间：
2000
影响因子：
11.1
通讯作者：
Menaker,M
中科院分区：
文献类型：
--
作者：
Tosini,G;Doyle,S;Geusz,M;Menaker,M
从5、7和9日龄的新生大鼠身上取出松果体，外植于短期培养中，在去甲肾上腺素（NE）刺激下合成褪黑激素；它们的褪黑素合成不能被明亮的白光抑制。分散的松果体细胞培养物或从1天大的新生儿中制备的松果体外植体，在培养7天或9天时，也会在NE刺激下合成褪黑激素，但在这些情况下，褪黑激素的合成被光显著抑制，表明松果体在培养过程中已经变得光敏。在培养液中持续存在1 μm或10 μm的NE可部分或完全消除培养物的光敏性。所有非哺乳动物脊椎动物的松果体都具有感光性，而哺乳动物的松果体通常对光没有反应。我们推测，利用交感神经末梢释放的NE抑制松果体光敏性的机制在哺乳动物历史早期就已经进化出来。
Pineal glands removed from neonatal rats at 5, 7, and 9 days of age and explanted into short-term culture, synthesized melatonin when stimulated with norepinephrine (NE); their melatonin synthesis could not be suppressed with bright white light. Dispersed pineal cell cultures or pineal explants prepared from 1-day-old neonates and held in culture for 7 or 9 days also synthesized melatonin when stimulated with NE, but in these cases melatonin synthesis was significantly suppressed by light, demonstrating that the pineals had become photosensitive while in culture. The development of photosensitivity in culture could be partially or completely abolished by the continuous presence of 1 or 10 μm of NE in the culture medium. The pineals of all nonmammalian vertebrates are photoreceptive, whereas those of mammals do not normally respond to light. We hypothesize that a mechanism to suppress pineal photosensitivity by using NE released from sympathetic nerve endings evolved early in the history of mammals.