Wang Chi, Zhou De-Feng, Shuai Xiao-Wei, Liu Jian-Xiang, Xie Peng-Yan
Department of Gastroenterology, Peking University First Hospital, 8 Xishiku street, Beijing 100034, China.
World J Gastroenterol. 2007 Sep 28;13(36):4873-80. doi: 10.3748/wjg.v13.i36.4873.
To investigate the effects of electroacupuncture (EA) at neiguan (PC6) on gastric distention-induced transient lower esophageal sphincter relaxations (TLESRs) and discuss the mechanisms of this treatment.
Protocol I: Twelve healthy cats underwent gastric distention for 60 min on the first day. Electrical acupoint stimulation was applied at the neiguan or a sham point on the hip in randomized order before gastric distention, on the third day and fifth day. Those cats that underwent EA at neiguan on the fifth day were named "Neiguan Group" and the cats that underwent EA at a sham acupoint on the fifth day were named "Sham Group" (control group). During the experiment the frequency of TLESRs and lower esophageal sphincter (LES) pressure were observed by a perfused sleeve assembly. Plasma levels of gastrin (GAS) and motilin (MTL) were determined by radioimmunoassay. Nitrite/nitrate concentration in plasma and tissues were measured by Griess reagent. The nuclei in the brain stem were observed by immunohistochemistry method of c-Fos and NADPH-d dyeing. Protocol II: Thirty six healthy cats were divided into 6 groups randomly. We gave saline (2 mL iv. control group), phaclofen (5 mg/kg iv. GABA-B antagonist), cholecystokinin octapeptide (CCK-8) (1 microg/kg per hour iv.), L-Arginine (200 mg/kg iv.), naloxone (2.5 micromol/kg iv.) and tacrine (5.6 mg/kg ip. cholinesterase inhibitor) respectively before EA at Neiguan and gastric distention. And the frequencies of TLESRs in experimental groups were compared with the control group.
Protocol I: Not only the frequency of gastric distention-induced TLESR in 60 min but also the rate of common cavity during TLESRs were significantly decreased by EA at neiguan compared to that of sham acupoint stimulation. C-Fos immunoreactivity and NOS reactivity in the solitarius (NTS) and dorsal motor nucleus of the vagus (DMV) were significantly decreased by EA at neiguan compared to that of the sham group. However, the positive nuclei of C-Fos and NOS in reticular formation of the medulla (RFM) were increased by EA at neiguan. Protocol II: The inhibited effect of EA at neiguan on TLESR's frequency was completely restored by pretreatment with CCK (23.5/h vs 4.5/h, P < 0.05), L-arginine (17.5/h vs 4.5/h, P < 0.05) and naloxone(12/h vs 4.5/h, P < 0.05). On the contrary, phaclofen (6/h vs 4.5/h, P > 0.05) and tacrine (9.5/h vs 4.5/h, P > 0.05) did not influence it.
Electric acupoint stimulation at Neiguan significantly inhibits the frequency of TLESR and the rate of common cavity during TLESR in cats. This effect appears to act on the brain stem, and may be mediated through nitric oxide (NO), CCK-A receptor and mu-opioid receptors. But the GABAB receptor and acetylcholine may not be involved in it.
探讨针刺内关穴对胃扩张诱发的一过性下食管括约肌松弛（TLESRs）的影响，并探讨其作用机制。
方案一：12只健康猫在第一天接受60分钟的胃扩张。在胃扩张前、第三天和第五天，分别以随机顺序对内关穴或臀部假穴进行电针刺激。将第五天接受内关穴电针刺激的猫命名为“内关组”，将第五天接受假穴电针刺激的猫命名为“假手术组”（对照组）。实验过程中，通过灌注套管组件观察TLESRs的频率和下食管括约肌（LES）压力。采用放射免疫分析法测定血浆胃泌素（GAS）和胃动素（MTL）水平。用Griess试剂测定血浆和组织中的亚硝酸盐/硝酸盐浓度。采用c-Fos免疫组化法和NADPH-d染色法观察脑干中的细胞核。方案二：36只健康猫随机分为6组。在针刺内关穴和胃扩张前，分别给予生理盐水（2 mL静脉注射，对照组）、巴氯芬（5 mg/kg静脉注射，GABA-B拮抗剂）、胆囊收缩素八肽（CCK-8）（1 μg/kg每小时静脉注射）、L-精氨酸（200 mg/kg静脉注射）、纳洛酮（2.5 μmol/kg静脉注射）和他克林（5.6 mg/kg腹腔注射，胆碱酯酶抑制剂）。并将实验组的TLESRs频率与对照组进行比较。
方案一：与假穴刺激相比，针刺内关穴不仅显著降低了60分钟内胃扩张诱发的TLESRs频率以及TLESRs期间的共同腔形成率。与假手术组相比，针刺内关穴显著降低了孤束核（NTS）和迷走神经背运动核（DMV）中的c-Fos免疫反应性和一氧化氮合酶（NOS）反应性。然而，针刺内关穴增加了延髓网状结构（RFM）中c-Fos和NOS的阳性细胞核。方案二：CCK（23.5次/小时对4.5次/小时，P < 0.05）、L-精氨酸（17.5次/小时对4.5次/小时，P < 0.05）和纳洛酮（12次/小时对4.5次/小时，P < 0.05）预处理完全恢复了针刺内关穴对TLESRs频率的抑制作用。相反，巴氯芬（6次/小时对4.5次/小时，P > 0.05）和他克林（9.5次/小时对4.5次/小时，P > 0.05）对其无影响。
针刺内关穴可显著抑制猫TLESRs的频率以及TLESRs期间的共同腔形成率。这种作用似乎作用于脑干，可能通过一氧化氮（NO）、CCK-A受体和μ-阿片受体介导。但GABAB受体和乙酰胆碱可能不参与其中。
