Melatonin modulates the light‐induced sympathoexcitation and vagal suppression with participation of the suprachiasmatic nucleus in mice
Melatonin modulates the light‐induced sympathoexcitation and vagal suppression with participation of the suprachiasmatic nucleus in mice
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DOI：
10.1111/j.1469-7793.2003.00317.x
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发表时间：
2003-02
期刊：
影响因子：
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通讯作者：
Tatsushi Mutoh;S. Shibata;H. Korf;H. Okamura
中科院分区：
文献类型：
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作者：
Tatsushi Mutoh;S. Shibata;H. Korf;H. Okamura
在哺乳动物中，自主神经系统调节从视交叉上核(SCN)到外周器官的中央昼夜时钟振荡，并控制心血管、呼吸和胃肠功能。本研究是在小鼠身上进行的，目的是研究传递到SCN的光信号是否可以控制外周自主神经功能，并进一步研究中枢应用褪黑素通过激活褪黑素受体信号对外周自主神经功能的影响。体内电生理技术在麻醉、开胸和人工呼吸的小鼠身上进行，同时监测动脉血压和心率。光照后即刻引起肾交感神经活动、动脉血压和心率增加。反之，光迅速抑制胃迷走神经的副交感神经活动，而肝迷走神经切断术和全横隔下迷走神经切断术都不影响胃迷走神经活动。这些自主神经反应是由SCN介导的，因为双侧SCN损毁完全取消了光诱发的神经和心血管反应。褪黑素侧脑室注射(i.c.v)抑制交感神经和迷走神经活动呈剂量依赖性，阈值为0.1 ng，这种作用可被侧脑室注射阻断。竞争性褪黑素受体拮抗剂Luzindole的前处理。这些结果表明，光通过SCN诱导交感兴奋和迷走抑制，褪黑素通过激活中枢褪黑素受体信号来调节光诱导的自主神经反应。
In mammals, the autonomic nervous system mediates the central circadian clock oscillation from the suprachiasmatic nucleus (SCN) to the peripheral organs, and controls cardiovascular, respiratory and gastrointestinal functions. The present study was conducted in mice to address whether light signals conveyed to the SCN can control peripheral autonomic functions, and further examined the impact of centrally administered melatonin on peripheral autonomic functions via activation of melatonin receptor signalling. In vivo electrophysiological techniques were performed in anaesthetised, open‐chest and artificially ventilated mice whilst monitoring the arterial blood pressure and heart rate. Light induced an increase of the renal sympathetic nerve activity, arterial blood pressure and heart rate immediately after lights on. Conversely, light rapidly suppressed the gastric vagal parasympathetic nerve activity, which was affected neither by hepatic vagotomy nor by total subdiaphragmatic vagotomy. These autonomic responses were mediated by the SCN since bilateral SCN lesion totally abolished the light‐evoked neuronal and cardiovascular responses. Melatonin administered intracerebroventricularly (i.c.v.) attenuated the sympathetic and vagal nerve activities in a dose‐dependent manner with a threshold of 0.1 ng and these effects were blocked by i.c.v. pre‐treatment of the competitive melatonin receptor antagonist luzindole. These results suggest that light induces sympathoexcitation and vagal suppression through the SCN and that melatonin modulates the light‐induced autonomic responses via activation of the central melatonin receptor signalling.