Li Wu, Xie Xiao-Yin, Tang Yuan-Wei, Wang Shu-Ya, Liu Kun, Liu Yun, Gao Xin-Yan, Cui Xiang, Zhu Bing
The First-class Discipline Lab of Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410007, China.
Institute of Acupuncture-moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700.
Zhen Ci Yan Jiu. 2021 Jan 25;46(1):27-32. doi: 10.13702/j.1000-0607.200778.
To observe the effect difference of electroacupuncture (EA) at the sensitized and non-sensitized acupoint "Tianshu" (ST25) on the motility of jejunum in rats.
Male SD rats were randomly divided into blank control, sensitized ST25 (sensitization), and non-sensitized ST25 (non-sensitization) groups (=16 in each group). The sensitization and non-sensitization were induced by injection of 15% mustard oil (20 μL) and Paraffin oil (20 μL) into the left ST25 area respectively. The rats' behavior reactions were assessed by recording the numbers and duration of licking the local sensitized skin region. At the end of experiments and after regular trans-cardiac perfusion and fixing with 10% neutral formaldehyde, the skin and muscular tissues of the ST25 region (1 cm×1 cm) were taken for H.E. staining to observe the local histopathologic changes. The intestinal motility was detected by recording the contraction pressure waves of jejunum through a small balloon-connected pressure transducer and an amplifier, followed by calculating the ratios of amplitude and frequency of contraction waves between pre- and post-EA stimulation. EA (2 Hz, 0.2-6.0 mA) was applied to the sensitized and non-sensitized ST25 regions for 20 s for comparing their effects on jejunum motility.
Compared with the blank control group, mustard oil injection but not Paraffin oil injection resulted in histological edema and neutrophils infiltration in tissues of ST25 region, and also striking increase of the number and duration of licking (<0.01), suggesting a sensitization of ST25 area after mustard oil injection. The ratios of spontaneous contraction amplitude and frequency of jejunum were remarkably decreased in mustard oil-treated rats compared to baseline and Paraffin oil group (<0.001，<0.01). The maximum inhibitory effect of EA on the intestinal movement amplitude was significantly higher in the sensitization group than in the blank control and non-sensitization groups (<0.05，<0.01), and there was a dose-effect relationship between the current intensity of EA (0.5-3.0 mA) and the inhibitory rate 50% of the contraction amplitude (not the frequency) in the sensitization group (<0.001), but not in the blank control and non-sensitization groups (>0.05). Additionally, 1.5 mA EA stimulation at the sensitized ST25 (not at the non-sensitized ST25) had an inhibitory effect on the contraction amplitude (<0.05) rather than on the contraction frequency (>0.05) in comparison with the blank control group.
Sensitization of acupoint ST25 can modulate the motility of jejunum and enhances the inhibitory effect of EA on the contraction amplitude of jejunum in rats. The inhibitory effect of sensitized ST25 EA is evidently stronger than that of the non-sensitized ST25 EA.
观察电针刺激致敏与非致敏状态下的“天枢”穴（ST25）对大鼠空肠运动的影响差异。
雄性SD大鼠随机分为空白对照组、致敏ST25组（致敏组）和非致敏ST25组（非致敏组），每组各16只。分别将15%芥子油（20 μL）和液体石蜡（20 μL）注射至左侧ST25区域，诱导大鼠穴位致敏和非致敏。通过记录大鼠舔舐局部致敏皮肤区域的次数和持续时间，评估大鼠行为反应。实验结束后，经心脏常规灌注10%中性甲醛固定，取ST25区域（1 cm×1 cm）皮肤及肌肉组织行苏木精-伊红（H.E.）染色，观察局部组织病理变化。通过连接小气囊的压力传感器和放大器记录空肠收缩压力波，检测肠道运动，并计算电针刺激前后收缩波的幅度和频率比值。分别对致敏与非致敏状态下的ST25区域施加频率2 Hz、强度0.2 - 6.0 mA的电针刺激20 s，比较二者对空肠运动的影响。
与空白对照组相比，注射芥子油而非液体石蜡能导致ST25区域组织出现组织学水肿和中性粒细胞浸润，同时舔舐次数和持续时间显著增加（P<0.01），提示芥子油注射后ST25区域致敏。与基线及液体石蜡组相比，芥子油处理的大鼠空肠自发收缩幅度和频率比值显著降低（P<0.001，P<0.01）。电针对肠道运动幅度的最大抑制作用在致敏组显著高于空白对照组和非致敏组（P<0.05，P<0.01），且致敏组电针电流强度（0.5 - 3.0 mA）与收缩幅度抑制率50%之间存在剂量效应关系（P<0.001），而空白对照组和非致敏组不存在此关系（P>0.05）。此外，与空白对照组相比，致敏ST25区域给予1.5 mA电针刺激（而非非致敏ST25区域）对收缩幅度有抑制作用（P<0.05），对收缩频率无抑制作用（P>0.05）。
穴位ST25致敏可调节大鼠空肠蠕动，并增强电针对大鼠空肠收缩幅度的抑制作用。致敏ST25区域电针的抑制作用明显强于非致敏ST25区域电针。
