胃经穴位电针调节胃运动的神经作用机制

目的胃经穴位电针对胃运动具有良好的调节作用，但其作用机制目前还不是很清楚。以往人们推测胃经穴位电针调节胃运动可能是通过对中枢某些核团的激活作用实现的。对此我们进行了相关的研究，并探讨其神经作用机制：方法采用同步实验，电生理学的方法，在电针足三里穴、上巨虚穴及非经非穴等穴位的情况下以及在离断迷走神经和坐骨神经条件下电针刺激足三里穴，观察延髓中与胃运动密切相关的孤束核(NTS)及迷走神经背运动核(DMV)中神经元细胞放电的变化情况，同时采用浆膜法检测胃电的变化。结果电针刺激足三里穴，在中枢延髓的孤束核(NTS)及迷走神经背运动核(DMV)中神经元细胞放电频率的变化以及胃电的变化情况均较明显，与电针刺激胃经其它穴位存在着显著差异。而在离断迷走神经或坐骨神经条件下，胃电未产生明显的变化。结论胃经穴位电针对胃运动具有调节作用。这种调节作用的实现，与孤束核(NTS）及迷走神经背运动核(DMV)的激活密切相关。而且，这种调节作用的完成依据于完整的神经途径。     

睡眠剥夺对大鼠胃运动及其神经中枢的影响

目的观察急性睡眠剥夺对胃排空及支配胃运动的神经中枢电生理活动的影响,为防治因睡眠剥夺对胃排空引起的胃动力障碍提供理论依据。方法采用同步实验,应用电生理学的方法,观察延髓中与胃运动密切相关的孤束核(nucleustractussolitary ,NTS)及迷走神经背运动核(Dorsalmotornucleusofthevagusnerve ,DMV)中神经元细胞放电的变化情况,同时采用浆膜法检测胃电的变化。结果随着睡眠剥夺时间的不断延长,延髓中与胃运动密切相关的孤束核(NTS)及迷走神经背运动核(DMV)中神经元细胞放电产生了不同的变化情况。在睡眠剥夺的第一周,迷走神经复合体的放电明显增加,胃电活动却呈现初始增加,逐渐减低状态,但无明显规律;而在睡眠剥夺的第二周,迷走神经复合体的放电呈现抑制状态,胃电活动呈现紊乱状态。结论急性睡眠剥夺对大鼠的胃运动影响明显,同时对支配胃运动的神经中枢亦有显著影响。     

辣椒素阻断迷走神经后胃电起搏诱导大鼠脑c-fos表达研究

目的以 c-fos 表达为观察指标,探讨迷走神经是否参与外源性胃电起搏调控胃肌电慢波活动。方法将雌性 Wistar 大鼠,分为手术对照组、胃电起搏组、辣椒素对照组和辣椒素胃电起搏组。电起搏组均给予电刺激,以控制慢波为准,持续刺激1 h。用 SP 免疫组化法观察 c-fos 在中枢延髓孤束核(NTS)及迷走神经运动背核(DMV)中的表达。结果胃电起博组 NTS 中 c-fos 阳性细胞数(75.00±9.03)明显高于辣椒素胃电起搏组(19.40±5.50),P<0.01;辣椒素胃电起搏组 NTS 中 c-fos 阳性细胞数与辣椒素对照组(14.00±3.39)和手术对照组(11.80±2.38)相比差异无统计学意义(P>0.05)。胃电起搏组 DMV 中 c-fos 阳性细胞数(35.00±6 28)明显高于辣椒素胃电起博组(13.80±4.21),P<0.01;辣椒素胃电起搏组 DMV 中 c-fos 阳性细胞数与辣椒素对照组(9.20±2.38)和于术对照组(8.20±2.17)相比差异无统计学意义(P>0.05)。结论外源性胃电起搏可调控胃肌电慢波活动,迷走神经可能参与这种调控作用。     

电针对LPS干预大鼠延髓NOS神经元的影响

目的探讨细菌脂多糖（LPs）对大鼠延髓一氧化氮合酶（NOS）神经元的影响，进一步观察电针足三里穴对这种影响的作用，并探讨其与胃排空功能的关系。方法。先行电针刺激大鼠足三里穴或非经非穴5天，之后予LPS2．5ms／kg腹腔注射，与不行电针单纯LPs处理组作对照；以免疫组化（ABC法）检测大鼠延髓神经元型NOS（nNOS）、诱导型NOS（iNOS）阳性神经元分布及数日，结果正常大鼠延髓各核团未观察到nNOS阳性神经元，延髓迷走神经背运动核（DMV）及孤束核（NTS）可见极少数iNOS阳性神经元分布。LPs腹腔注射7．5h后，延髓DMV中nNOS、iNOS阳性神经元的数目均明显增多；若先予以电针足三里穴5天，则可明届抑制LPS引起的此种反应（P＜0．01），而非经非穴点电针效果不明显。大鼠腹腔注射LPs后，延髓DMV中nNOS及iNOS阳性细胞数日明显增加，电针足三里穴可使之明显减少。结论电针对胃运动的作用可能与其对DMV中NO合成神经元的作用有关。     

胃电刺激诱导大鼠延髓孤束核和迷走神经运动背核c-fos蛋白表达

背景：胃电刺激（GES）可以调控胃慢波，但其作用机制尚不完全清楚。原癌基因蛋白c—fos的表达可作为神经元功能活动的标志物。目的：以c-fos蛋白的表达为观察指标，探讨GES调控胃肌电慢波的神经机制。方法：将雌性Wistar大鼠随机分为对照组和GES组。GES以控制胃慢波为准，持续1h。分别于刺激后0．5、1、2和5h处死大鼠，以免疫组化方法观察c—fos蛋白在延髓孤束核和迷走神经运动背核中的表达。结果：对照组延髓孤束核和迷走神经运动背核仅见微量c—fos蛋白表达，GES后0．5h其表达开始增强，1h时达高峰，以后逐渐减弱。结论：GES可以调控胃肌电慢波，GES后延髓孤束核和迷走神经运动背核神经元c-fos蛋白表达阳性提示迷走神经可能参与了该调控作用。     

电针对胃动力紊乱大鼠血管活性肠肽表达的影响

[目的]探讨电针调整胃动力与血管活性肠肽(VIP)的内在联系.[方法]采用浆膜法测定胃电数据,放射和免疫组化方法观察针刺足三里穴对束缚冷应激致胃动力紊乱大鼠VIP表达的影响.[结果]与正常组比较,束缚冷应激大鼠胃运动频率和波幅升高(P＜0.01);与模型组比较,电针足三里穴可降低胃运动频率和波幅(P＜0.01),同时可影响VIP的表达(P＜0.05,＜0.01).[结论]VIP参与了电针对胃动力的调整作用.     

大鼠迷走神经背核在电针保护胃粘膜损伤中的作用

研究了大鼠迷走神经背核（DMV）在调节胃功能和影响电针保护胃粘膜损伤中的作用。电损毁DMV组与假手术组和掼毁其他脑组织组（网状巨细胞核）比较，可降低胃粘膜血流量和跨膜电位差，在应激后更加剧（P＜0．01）。损毁DMV后能基本消除电针对胃粘膜损伤的保护作用。结果提示，中枢迷走通路，特别是DMV在调整胃功能和影响电针的保护效应中起重要作用。     

交感神经和肌间神经丛在胃电刺激调控胃慢波中的作用

目的研究胃交感神经及肌间神经丛在电刺激调控胃慢波活动中的作用,确定胃电起博的神经机制和作用环节,为今后起搏器的深入研究打下基础。方法10只雄性wistar大鼠随机分为对照组和电刺激组,各5只。全部大鼠植入浆膜电极,电刺激组大鼠行胃电刺激至胃慢波被完全控制。植入电极组不行电刺激。采用免疫组化S P法检测并比较两组大鼠胃窦肌间神经丛和脊髓后角C fos蛋白表达。结果电刺激组大鼠胃慢波全部被完全控制,所需能量为2 70±80 .6ms ,2mA。2组大鼠脊髓中间内侧核,中间外侧核均未见C fos阳性神经元,而后角浅层均见散在C fos表达,比较无显著性差异(P >0 .0 5 )。植入电极组胃窦肌间神经丛未见C fos阳性神经元,电刺激组胃窦肌间神经丛可见C fos阳性神经元。结论适宜参数的胃电刺激可完全控制大鼠胃慢波。肌间神经丛参与胃电刺激调控胃慢波,而交感神经则无明显作用。     

电针足三里和阳陵泉穴对家兔胃胆运动及脑肠肽的影响

目的:研究经脉-脏腑相关理论及经穴对相应脏腑的特异性作用．方法:静脉滴注阿托品造成家兔(n=50)胃和 Oddi括约肌运动抑制状态,观察电针家兔足三里穴及阳陵泉穴对胃电及Oddi括约肌肌电的影响并检测血浆和胃窦平滑肌及Oddi括约肌组织中胃动素(MTL)胆囊收缩素(CCK)的含量．结果:静滴阿托品后家兔胃电和Oddi括约肌肌电慢波高活动相平均振幅(P=0．001和快波平均振幅(P=0．028,P=0．001)明显降低;慢波平均频率变化不明显．电针足三里穴和阳陵泉穴对家兔胃电(P=0．020,P=0．0001及Oddi 括约肌肌电(P=0．021,P=0．001)平均振幅有不同程度的兴奋作用,表明经脉-脏腑之间既有直接相关又有间接相关．电针足三里穴和阳陵泉穴可升高胃窦平滑肌、Oddi括约肌组织及血浆中MTL(P=0．000)、CCK((P=0．001)含量．电针足三里穴对胃窦平滑肌和血浆MTL (P=0．020,P=0．001)及血浆CCK(P=0．001)含量升高最显著,差异有显著性意义．Oddi括约肌MTL及胃窦平滑肌、Oddi括约肌CCK以电针阳陵泉穴明显．提示MTL和CCK是参与针刺调整消化道运动的重要脑肠肽物质．结论:电针足三里和阳陵泉穴可促进胃和 Oddi括约肌运动,其机制之一可能为针刺影响外周MTL、CCK的释放,进而调整消化道运动．这种经穴对相应脏腑的调整作用具有相对特异性．     

C纤维在电针口面部穴位镇痛效应中的作用

目的 其完全恢复后电针双侧四白穴20 min,再腹腔注射乙酸造成内脏痛模型;溶媒+电针+内脏痛组大鼠用溶媒处理双侧眶下神经,其余处理同辣椒素+电针+内脏痛组.各组大鼠处理完毕后,观察大鼠的行为学变化(扭体反应)以及孤束核(nucleus of the solitary tract,NTS)和三叉旁核(paratrigeminal nucleus,PTN)的c-fos表达.结果 (1)电针+内脏痛组腹部收缩次数较内脏痛组明显减少(P<0.01);辣椒素+电针+内脏痛组大鼠腹部收缩次数较电针+内脏痛组明显增加(P<0.05);溶媒+电针+内脏痛组大鼠腹部收缩次数较内脏痛组明显减少(P<0.05).(2)电针+内脏痛组NTS的c-fos表达较内脏痛组明显减少(P<0.05);辣椒素+电针+内脏痛组NTS的c-fos表达较电针+内脏痛组明显增加(P<0.01).(3)电针+内脏痛组PTN的c-fos表达较内脏痛组明显增加(P<0.01);辣椒素+电针+内脏痛组PTN的c-fos表达较电针+内脏痛减弱(P<0.05);溶媒+电针+内脏痛组PTN的c-fos表达较辣椒素组显著增加(26.3±4.50 vs 11.7±2.44,P<0.01).结论 C纤维在电针口面部穴位对内脏痛的镇痛效应中有重要作用,口面部的躯体感觉传入通过C纤维经PTN中继后与内脏的感觉传入可能在NTS发生汇聚并进行整合,从而产生镇痛作用.     

Electro-acupuncture of Tsusanli and Shangchuhsu regulates gastric activity possibly through mediation of the vagus-solotary complex

BACKGROUND/AIMS: Acupuncture has been reportedly used to treat gastrointestinal diseases, however, its precise mechanism remains unknown. METHODOLOGY: In our study, the effects and mechanism of electro-acupuncture (EA) at Tsusanli (ST 36), Shangchuhsu (ST 37) on regulation of gastric activity were observed. RESULTS: EA at Tsusanli showed that gastric electric change was the most obvious, with significantly higher frequency and wave amplitude compared with that of the Shangchuhsu group and other groups. EA at Shangchuhsu demonstrated that the change of gastric electric level was much higher than that of the non-acupoint group and control group. After bilateral vagotomy, Tsusanlis was electro-acupunctured, the changes of electro-gastric graph (EGG) weren't significant with the control group. The frequency of electro-physiological activity in nucleus of solitary tract (NTS) and dorsal motor nucleus of the vagus nerve (DMV) in the Tsusanli group was markedly increased compared with that in the other group. Fos and GFAP expression in NTS and DMV in the Tsusanli group was significantly higher than that in other groups and control group. The results have indicated that EA at Tsusanli and Shangchuhsu cannot only regulate gastric activity, but also activate neurons and astrocytes in NTS and DMV. The effects on regulation and activation of EA at Tsusanli were very obvious. CONCLUSIONS: Our study suggests that this electroacupuncture regulation of gastric activity may partially depend upon integrated nerve pathway and related central neurons and astrocytes in the vagus-solitary complex.     

白萝卜提取物对胃动力的影响

目的探讨萝卜提取物（Crude radish extract,Ecr）对胃动力的作用,为开发中药提供新的途径。方法在前期工作的基础上,采用灌胃给药方法,给大鼠以最有效剂量的萝卜提取物按60mg/kg灌胃后,经胃电记录,观察其对胃运动的影响,并对其对中枢支配胃运动的迷走复合体（dorsal vagal complex,DVC）中神经元放电频率的变化以及c-Fos表达的情况为标志,观察上述两个核团中神经元被激活状况,来探讨萝卜提取物促胃动力的作用机制。结果给药30min大鼠的胃电变化最为明显,给药45min后药物的作用逐渐降低,给药60min后胃电的变化基本接近于正常对照组。神经元的放电和Fos的表达情况与胃电变化情况相近。结论萝卜提取物对胃有较为明显的动力作用,而且按60mg/kg给药后的30min其促动力作用最为明显。     

短波胃电刺激对大鼠孤束核及下丘脑c-fos表达的影响及其机制

目的 探讨肠肌间神经丛及中枢神经系统相关核团(孤束核及下丘脑)是否参与介导外源性短波胃电刺激调控中枢感觉功能.方法 雄性Wistar大鼠15只,分为对照组、胃电刺激组、去肠肌间神经丛组,均于胃底、胃体交界处植入一对电极,去肠肌间神经丛组大鼠同时胃浆膜面予苯扎氯胺处理,后两组均予短波胃电刺激,持续30 min.SP免疫组化法观察延髓孤柬核及下丘脑c-fos表达.结果 胃电刺激组和去肠肌间神经丛组大鼠每高倍视野下孤束核处c-fos阳性神经元数量分别为(71.6±7.4)和(63.4±10.8)个,下丘脑处则分别为(224.2±47.3)和(249.1±44.0)个,两组间差异无统计学意义(P＞0.05),但均显著高于对照组[(36.4±8.6)和(90.2±47.3)个,P值均＜0.05].结论 孤束核及下丘脑可能是介导短波胃电刺激治疗作用的中枢核团,而肠神经系统不参与介导此作用.     

Expression and localization of c-Fos and NOS in the central nerve system following esophageal acid stimulation in rats

AIM: To determine the distribution of neurons expressing c-Fos and nitric oxide synthase (NOS) in the central nerve system (CNS) following esophageal acid exposure, and to investigate the relationship between c-Fos and NOS. METHODS: Twelve Wistar rats were randomly divided into two equal groups. Hydrochloric acid with pepsin was perfused in the lower part of the esophagus for 60 min. As a control, normal saline was used. Thirty minutes after the perfusion, the rats were killed and brains were removed and processed for c-Fos immunohistochemistry and NADPH-d histochemistry. Blood pressure (BP), heart rate (HR), and respiratory rate (RR) during the experimental procedures were recorded every 10 min. RESULTS: There were no significant differences in BP, HR and RR between the two groups. c-Fos immunoreactivity was significantly increased in rats receiving acid plus pepsin perfusion in amygdala (AM), paraventricular nucleus (PVN), parabrachial nucleus (PBN), nucleus tractus solitarius and dorsal motor nucleus of vagus (NTS/DMV), nucleus ambiguous (NA), reticular nucleus of medulla (RNM) and area postrema (AP). NOS reactivity in this group was significantly increased in PVN, PBN, NTS/DMV, RNM and AP. c-Fos and NOS had significant correlation between PVN, PBN, NTS/DMV, RNM and AP. CONCLUSION: Acid plus pepsin perfusion of the esophagus results in neural activation in areas of CNS, and NO is likely one of the neurotransmitters in some of these areas.     

Role of Medullary Cholinoceptors in Baroreflex Bradycardia

Cholinergic receptors present in three medullary nuclei namely, the nucleus tractus solitarii (NTS), nucleus ambiguus (AMB) and the dorsal motor nucleus of the vagus nerve (DMV) have been studied with regard to their role in regulation of heart rate (HR), blood pressure (BP) and baroreceptor reflex activation induced bradycardia in cats.

Microinjection of carbachol into NTS was without effect while administration of carbachol or pilocarpine into AMB and DMV elicited dose related decrease in HR without affecting BP. These effects were completely antagonized by ethylbenztropine. Bilateral muscarinic cholinoceptor blockade of either AMB or DMV, with ethylbenztropine, produced a partial inhibition of the baroreflex bradycardia while intra-cisternal ethylbenztropine completely abolished this reflex response. Involvement of muscarinic cholinoceptors of AMB or DMV in baroreflex mediated adjustments of HR is therefore suggested.     

Effects and mechanisms of electroacupuncture at PC6 on frequency of transient lower esophageal sphincter relaxation in cats

AIM: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.     

Localization and activation of glucagon-like peptide-2 receptors on vagal afferents in the rat

Glucagon-like peptide-2 (GLP-2) is a nutrient-dependent proglucagon-derived hormone that stimulates intestinal growth through poorly understood paracrine and/or neural pathways. The relationship between GLP-2 action and a vagal pathway is unclear. Our aims were to determine whether 1) the GLP-2 receptor (GLP-2R) is expressed on vagal afferents by localizing it to the nodose ganglia; 2) exogenous GLP-2 stimulates the vagal afferent pathway by determining immunoreactivity for c-fos protein in the nucleus of the solitary tract (NTS); and 3) functional ablation of vagal afferents attenuates GLP-2-mediated intestinal growth in rats maintained with total parenteral nutrition (TPN). A polyclonal antibody against the N terminus of the rat GLP-2R was raised and characterized. The GLP-2R was localized to vagal afferents in the nodose ganglia and confirmed in enteroendocrine cells, enteric neurons, and nerve fibers in the myenteric plexus using immunohistochemistry. Activation of the vagal afferent pathway, as indicated by c-fos protein immunoreactivity in the NTS, was determined by immunohistochemistry after ip injection of 200 microg human GLP-2. GLP-2 induced a significant 5-fold increase in the number of c-fos protein immunoreactive neurons in the NTS compared with saline. Ablation of vagal afferent function by perivagal application of capsaicin, a specific afferent neurotoxin, abolished c-fos protein immunoreactivity, suggesting that activation of the NTS due to GLP-2 is dependent on vagal afferents. Exogenous GLP-2 prevented TPN-induced mucosal atrophy, but ablation of vagal afferent function with capsaicin did not attenuate this effect. This suggests that vagal-independent pathways are responsible for GLP-2 action in the absence of luminal nutrients during TPN, possibly involving enteric neurons or endocrine cells. This study shows for the first time that the GLP-2R is expressed by vagal afferents, and ip GLP-2 activates the vagal afferent pathway.