Yu Qing-Quan, Li Tong, Zhnag Zhi-Yun, Su Yang-Shuai, He Wei, Wang Yi, Zhang Xiao-Ning, Jing Xiang-Hong
Intitute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Hubei University of TCM.
Zhongguo Zhen Jiu. 2021 Jan 12;41(1):45-51. doi: 10.13703/j.0255-2930.20200914-k0003.
To observe the effect of electroacupuncture (EA) at sensitized acupoints on choline acetyltransferase positive (ChAT) neurons in dorsal motor nucleus (DMV) of brainstem vagus in the colitis model rats and explore the mechanism of the improvement in colonic inflammatory injury in the rats.
A total of 79 male SD rats were randomized into five groups, i.e. a normal group (20 rats), a normal plus sensitized acupoint group (5 rats), a model group (34 rats), an EA1 group (15 rats) and an EA2 group (5 rats). In the model group and the EA groups, 5% dextran sulfate sodium (DSS) was adopted for 6day free drinking to establish colitis model rats. By injecting Evans blue (EB) into the caudal vein in the model rats, the sensitized acupoints were determined. Afterwards, in the normal plus sensitized acupoint group, the EA1 group and the EA2 group, EA was exerted at the sensitized acupoints, with disperse-dense wave, 2 Hz/ 15 Hz in frequency and 2 mA in intensity, for 30 min of intervention each day. The intervention lasted for 6 days in the EA1 group and for 1 day in both the normal plus sensitized acupoint group and the EA-2 group. On day 0, 7 and 13 of experiment, successively, the score of disease activity index (DAI), the score of colonic histological damage, as well as the changes in the mechanical paw withdrawal threshold and thermal paw withdrawal latency were evaluated in the normal group, the model group and the EA-1 group. On day 7 of experiment, using immunofluorescence staining, the activation of different lamina neurons of spinal dorsal horn and ChAT neurons in DMV was observed in the normal group, the normal plus sensitized acupoint group, the model group and the EA-2 group separately.
The EB extravasating areas were distributed in the segments from T to S on the body surface of colitis model rats, mainly focusing at L and L. Therefore, "Shangjuxu" (ST 37) was taken as the sensitized acupoint. Compared with the normal group on day 7 and 13 of experiment, the mechanical paw withdrawal threshold were reduced (<0.001), DAI scores and the scores of colonic histological damage were increased (<0.001) in the model group. Compared with the normal group on day 7 of experiment, thermal paw withdrawal latency in the model group was reduced (<0.001). Compared with the model group on day 13 of experiment, the mechanical paw withdrawal threshold was increased (<0.001), DAI score and the score of colonic histological damage were reduced (<0.01, <0.05) in the EA-1 group. Compared with the normal group, the activated numbers of the neurons in superficial laminae (Ⅰand Ⅱ) at spinal dorsal horn of L to L and ChAT neurons in DMV were increased in the normal plus sensitized acupoint group and the model group (<0.05, <0.01). Compared with the normal plus sensitized acupoint group and the model group, the activated numbers of the neurons in superficial laminae at spinal dorsal horn of L to L and ChAT neurons in DMV were increased in the EA-2 group (<0.001).
The segmental dominance (acupoints) from T to S on the body surface of colitis rats is sensitized. EA at sensitized acupoints effectively relieves colonic inflammatory injury, which is probably by activating superficial lamina neurons of spinal dorsal horn and ChAT neurons of DMV.
观察电针（EA）刺激致敏穴位对结肠炎模型大鼠脑干迷走神经背核（DMV）中胆碱乙酰转移酶阳性（ChAT）神经元的影响，探讨其改善大鼠结肠炎症损伤的机制。
将79只雄性SD大鼠随机分为5组，即正常组（20只）、正常加致敏穴位组（5只）、模型组（34只）、EA1组（15只）和EA2组（5只）。模型组和EA组采用5%葡聚糖硫酸钠（DSS）自由饮用6天建立结肠炎模型大鼠。通过向模型大鼠尾静脉注射伊文思蓝（EB）确定致敏穴位。之后，正常加致敏穴位组、EA1组和EA2组在致敏穴位施加EA，采用疏密波，频率为2Hz/15Hz，强度为2mA，每天干预30分钟。EA1组干预6天，正常加致敏穴位组和EA-2组均干预1天。在实验第0、7和13天，依次评估正常组、模型组和EA-1组的疾病活动指数（DAI）评分、结肠组织学损伤评分以及机械性缩爪阈值和热缩爪潜伏期的变化情况。在实验第7天分别采用免疫荧光染色观察正常组、正常加致敏穴位组、模型组和EA-2组脊髓背角不同板层神经元的激活情况以及DMV中ChAT神经元的激活情况。
结肠炎模型大鼠体表EB外渗区域分布于胸段（T）至骶段（S），主要集中在腰段（L）和腰段（L）。因此，选取“上巨虚”（ST37）作为致敏穴位。与实验第7天和13天的正常组相比，模型组的机械性缩爪阈值降低（< 0.001），DAI评分和结肠组织学损伤评分升高（< 0.001）。与实验第7天正常组相比，模型组的热缩爪潜伏期缩短（< 0.001）。与实验第13天模型组相比，EA1组的机械性缩爪阈值升高（< 0.001），DAI评分和结肠组织学损伤评分降低（< 0.01，< 0.05）。与正常组相比，正常加致敏穴位组和模型组腰段（L）至腰段（L）脊髓背角浅层（Ⅰ和Ⅱ）神经元以及DMV中ChAT神经元的激活数量增加（< 0.05，< 0.01）。与正常加致敏穴位组和模型组相比，EA-2组腰段（L）至腰段（L）脊髓背角浅层神经元以及DMV中ChAT神经元的激活数量增加（< 0.001）。
结肠炎大鼠体表胸段（T）至骶段（S）存在节段性优势（穴位致敏）。电针刺激致敏穴位可有效减轻结肠炎症损伤，其机制可能是通过激活脊髓背角浅层神经元和DMV中的ChAT神经元实现的。
