Wang Y J, Wang S K
Zhen Ci Yan Jiu. 1989;14(4):420-3.
In the present study, rats were synchronized with light from 8:00 to 20:00, then darkness. Water and food were available ad libitum. The basic levels in medulla oblongata plus pons, hypothalamus, hippocampus midbrain, striatum and cortex, and electroacupuncture influences on them were compared at four different times of a day (5:00, 11:00, 17:00 and 23:00). It was found that: (1) The basic level of LEK in the medulla oblongata plus pons at 11:00 was the highest among the four times; (2) The LEK content increased by 34.8% in the hypothalamus and decreased by 21.4% in the cortex when EA was given at 5:00; The LEK levels in the hypothalamus and the hippocampus increased by 65.3% and by 37.0% respectively when EA at 11:00. The LEK level in the hippocampus increased by 50.1% when EA at 17:00; The hippocampus decreased by 29.8% when EA at 23:00. The results show that a circadian rhythm was evident in the LEK level of the rat medulla oblongata plus pons, also EA at different hours produced different effects on LEK contents in rat discrete brain regions. This provides experimental evidence for acupuncture treatment selecting hours clinically. Also, the physiological circadian variation and the influence of time factor on acupuncture effects should be considered in study of acupuncture mechanism.
在本研究中，大鼠的光照时间设定为8:00至20:00，之后为黑暗时间。水和食物可随意获取。在一天的四个不同时间点（5:00、11:00、17:00和23:00）比较了延髓加脑桥、下丘脑、海马、中脑、纹状体和皮质中的基础水平，以及电针对它们的影响。结果发现：（1）11:00时延髓加脑桥中亮氨酸脑啡肽（LEK）的基础水平在四个时间点中最高；（2）5:00进行电针时，下丘脑LEK含量增加34.8%，皮质中LEK含量下降21.4%；11:00进行电针时，下丘脑和海马中LEK水平分别增加65.3%和37.0%；17:00进行电针时，海马中LEK水平增加50.1%；23:00进行电针时，海马中LEK水平下降29.8%。结果表明，大鼠延髓加脑桥中LEK水平存在明显的昼夜节律，不同时间点的电针对大鼠不同脑区的LEK含量产生不同影响。这为临床针灸治疗选时提供了实验依据。此外，在针灸机制研究中应考虑生理昼夜变化和时间因素对针刺效应的影响。
