Circadian rhythms of cardiovascular functions are modulated by the baroreflex and the autonomic nervous system in the rat
Circadian rhythms of cardiovascular functions are modulated by the baroreflex and the autonomic nervous system in the rat
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DOI：
10.1161/01.cir.96.5.1667
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发表时间：
1997-09-02
期刊：
影响因子：
37.8
通讯作者：
Ebihara, S
中科院分区：
文献类型：
--
作者：
Makino, M;Hayashi, H;Ebihara, S
背景我们评估了压力感受器反射和自主神经系统在控制心血管功能昼夜节律中的重要作用的假说。方法和结果我们利用无线电遥测系统连续测量了去窦弓神经(SAD)、去交感神经和注射阿托品的大鼠的血压(BP)、心率(HR)和运动活动。在12小时明暗(LD12：12)周期下，SAD大鼠的平均血压(MBP)昼夜节律被选择性地打乱，这是由于光照期间平均血压(MBP)的增加，并在恒定的黑暗(DD)下消失。SAD对运动活动和心率的影响不明显。切断交感神经的大鼠在黑暗期间MBP的昼夜节律被抑制，而在LD下，改变光照时MBP的突变不明显。在DD模式下，获得了与LD模式相似的MBP节律。切断交感神经的大鼠在暗期的HR水平也低于LD周期下的正常大鼠。在注射阿托品的大鼠，MBP和HR升高，特别是在光照期间，导致MBP和HR的明暗差异缩小。结论压力感受性反射的破坏选择性地消除了大鼠血压的昼夜节律，自主神经系统调节了血压和心率的昼夜节律。血压和心率的昼夜节律受到涉及自主神经系统的不同机制的调节。
Background We assessed the hypothesis that the baroreflex and the autonomic nervous system are important in the control of the circadian rhythms of cardiovascular functions.Methods and Results We continuously measured blood pressure (BP), heart rate (HR); and locomotor activity in sinoaortic denervated (SAD), sympathectomized, and atropine-injected rats by use of a radiotelemetry system. The circadian rhythm of mean blood pressure (MBP) was selectively disrupted in SAD rats under 12-hour light-dark (LD12:12) cycles as a result of an increase in MBP during the light period and disappeared under constant darkness (DD). The locomotor activity and HR were not remarkably affected by SAD. The circadian rhythm of MBP was suppressed in sympathectomized rats by a decrease in the MBP during the dark period, and the abrupt changes in MBP when the lighting was altered were not seen under LD. Under DD, an MBP rhythm similar to that observed under LD was obtained. Sympathectomized rats also showed lower HR levels during the dark period than intact rats under LD cycles. In atropine-injected rats, the MBP and HR increased, especially during the light period, resulting in a reduction of light-dark differences in MBP and HR. The locomotor activity showed an apparent 24-hour variation in the sympathectomized and atropine-injected rats.Conclusions The disruption of the baroreflex selectively eliminates the circadian rhythm of BP, and the circadian rhythms of BP and HR are modulated by the autonomic nervous system in rats. The circadian rhythms of BP and HR are regulated by different mechanisms involving the autonomic nervous system.