Daily NO rhythms in peripheral clocks in aging male Wistar rats: protective effects of exogenous melatonin
Daily NO rhythms in peripheral clocks in aging male Wistar rats: protective effects of exogenous melatonin
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DOI：
10.1007/s10522-016-9656-6
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发表时间：
2016-09
期刊：
影响因子：
4.5
通讯作者：
Ch. Vinod;A. Jagota
中科院分区：
文献类型：
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作者：
Ch. Vinod;A. Jagota
在哺乳动物视交叉上核（SCN）中，视交叉上核充当光可振荡的主时钟，并且通过产生时间振荡来调节充当自主时钟的外周器官，从而导致明显的行为和生理节律。SCN还控制松果体褪黑激素（黑暗的激素信息）的合成和释放。一氧化氮（NO）作为一种重要的神经递质，参与昼夜节律的相位变化，参与睡眠-觉醒过程，维持血管紧张度，以及信号传导和调节炎症过程。衰老与昼夜节律定时系统的破坏和内源性褪黑激素的下降相关，导致几种生理障碍。在这里，我们报告了衰老对肾脏、肠、肝脏、心脏、肺和睾丸等各种外周生物钟中NO日节律的影响。采用Griess法测定大鼠不同时间（ZT 0、6、12、18）脑组织中NO含量。增龄12和24个月组的NO水平和NO时相均发生改变。相关性分析表明，随着年龄的增长，各种外围时钟之间的化学计量相互作用的损失。年龄引起的NO日节律的变化被认为是最显着的肝脏，有趣的是，在肺最少。神经激素褪黑激素是一种内源性同步剂和抗衰老剂，随着年龄的增长而减少。我们报告了进一步的差异恢复与外源性褪黑激素管理年龄引起的变化，在NO的日常节奏和平均水平在肾脏，肠道和肝脏和化学计量的各种外周时钟之间的相互作用。
In mammals suprachiasmatic nucleus (SCN), acts as a light entrainable master clock and by generation of temporal oscillations regulates the peripheral organs acting as autonomous clocks resulting in overt behavioral and physiological rhythms. SCN also controls synthesis and release of melatonin (hormonal message for darkness) from pineal. Nitric Oxide (NO) acts as an important neurotransmitter in generating the phase shifts of circadian rhythms and participates in sleep–wake processes, maintenance of vascular tone as well as signalling and regulating inflammatory processes. Aging is associated with disruption of circadian timing system and decline in endogenous melatonin leading to several physiological disorders. Here we report the effect of aging on NO daily rhythms in various peripheral clocks such as kidney, intestine, liver, heart, lungs and testis. NO levels were measured at zeitgeber time (ZT) 0, 6, 12 and 18 in these tissues using Griess assay in male Wistar rats. Aging resulted in alteration of NO levels as well as phase of NO in both 12 and 24 months groups. Correlation analysis demonstrated loss of stoichiometric interaction between the various peripheral clocks with aging. Age induced alterations in NO daily rhythms were found to be most significant in liver and, interestingly least in lungs. Neurohormone melatonin, an endogenous synchroniser and an antiaging agent decreases with aging. We report further differential restoration with exogenous melatonin administration of age induced alterations in NO daily rhythms and mean levels in kidney, intestine and liver and the stoichiometric interactions between the various peripheral clocks.