慢传输型便秘患者结肠中五羟色胺受体亚型的表达及意义

目的:研究主要5-HT受体亚型在慢传输型便秘(slowtransitconstipation,STC)患者结肠中的表达,探讨其在慢传输型便秘发病机制中的作用.方法:采用免疫组化EnVision法,检测20例STC患者和20例对照组结肠组织中5-HT1A,5-HT3和5-HT4受体的分布及表达水平,并采用IMS计算机辅助图像分析系统进行半定量分析.结果:5-H1A受体分布于黏膜下层、肌层,肌间神经丛5-HT1A受体的表达在STC组和对照组间无显著差异(P=0.548).5-HT3受体分布于黏膜下层和肌层,肌间神经丛STC组阳性指数显著低于对照组(65.2±15.9vs94.3±20.1,P<0.01).5-HT4受体分布于黏膜层、黏膜下层、肌层.在黏膜层和肌间神经丛,STC组5-HT4受体阳性指数均显著低于对照组(57.8±10.9vs78.5±12.9,P<0.01;77.5±19.9,119.2±26.9,P<0.01).STC组中,5-HT3受体表达水平与结肠传输试验第5天体内残留标志物数量无关(P>0.05);但5-HT4受体表达水平与第5天体内残留标志物数量呈负相关(r=-0.782,P<0.01).结论:STC患者结肠中存在5-HT3和5-HT4受体亚型的表达下调,两者可能参与了STC的发病机制.     

健脾化湿颗粒对腹泻型肠易激综合征大鼠结肠5-羟色胺、5-羟色胺3受体的影响

目的探讨健脾化湿颗粒对腹泻型肠易激综合征(D-IBS)模型大鼠结肠中5-羟色胺(5-HT)和5-羟色胺3受体(5-HT3R)水平的影响。方法选用60只SD雄性大鼠,按体重随机分成六组,分别为正常组,模型组,健脾化湿颗粒低、中、高剂量组,阳性对照组。采用酶联免疫吸附法(ELISA)检测大鼠结肠黏膜中5-HT含量,采用免疫组化法检测结肠黏膜下5-HT3R阳性细胞的表达量,采用逆转录聚合酶链反应(RT-PCR)法检测结肠中5-HT3R mRNA的表达水平。结果与正常组相比,模型组结肠中5-HT水平显著升高(P0.05),结肠黏膜下层5-HT3R阳性细胞的含量明显升高(P0.05),结肠中5-HT3R mRNA的表达水平亦显著升高(P0.05);健脾化湿颗粒可以降低5-HT水平,5-HT3R水平及其mRNA表达量。结论健脾化湿颗粒可能通过降低结肠黏膜5-HT含量,减少结肠5-HT3R的表达量,减弱5-HT3R神经元兴奋性,从而改善内脏痛觉敏感状态,消除肠道反应。     

"泻剂结肠"大鼠胃肠道黏膜嗜铬细胞及5-HT的变化

目的 探讨"泻剂结肠"致慢传输型便秘(STC)的发病机制.方法 采用大黄浸液灌胃建立大鼠STC模型,免疫组化法观察不同时期大鼠胃肠道黏膜嗜铬细胞的改变,荧光分光光度法检测十二指肠、乙状结肠组织匀浆及血清5-HT的变化.结果 实验组大鼠半数稀便时,各段胃肠道嗜铬细胞密度明显低于对照组,80%稀便消失时,胃肠道各段肠嗜铬细胞密度增高,接近对照组;STC模型大鼠胃肠道各段嗜铬细胞密度高于对照组(胃窦、空肠、盲肠P<0.01,回肠P<0.05),十二指肠、乙状结肠组织匀浆5-HT含量明显高于对照组(P<0.01),两组血清5-HT含量无显著差异(P＞0.05).结论 泻剂影响整个胃肠道黏膜;泻剂致STC,归因于肠嗜铬细胞对泻剂刺激逐渐耐受,5-HT释放减少,胃肠道运动减慢.     

不同年龄大鼠消化道Cajal细胞c-kit受体表达的变化及意义

目的通过检测不同年龄组SD大鼠的肠道推进率及胃肠肌间Cajal间质细胞(ICC)的c-kit受体表达,探讨生理性衰老过程中大鼠胃肠运动、感觉和分泌等生理功能变化的规律与机制。方法 90只健康成年SD大鼠按不同年龄分为3、9、18、24及30月龄5组,每组各16只。以印度墨汁为标记物,检测并计算每组8只大鼠的肠道推进率。采用免疫组化SABC法染色,检测每组各8只大鼠胃体、空肠、回肠、结肠和乙状结肠与直肠交界的肌间ICC的c-kit受体表达,比较这些指标在不同年龄组的变化规律。结果①大鼠肠道推进率从3月龄的(67.2±13.5)%逐渐减少到30月龄的(52.1±9.8)%(P<0.01);②与3月龄组、9月龄组和18月龄组大鼠相比,老年大鼠(24月龄和30月龄)肌间ICC c-kit受体表达显著下调,其中以乙状结肠与直肠交界处变化最为显著(P<0.05)。结论在大鼠生理性衰老过程中,胃肠运动功能及肌间ICC的功能均随之显著下调,并且随年龄的增加这种变化更为明显。在生理性衰老过程中,这些变化可能参与了老年人胃肠功能紊乱性疾病的发病。     

大鼠泻剂结肠肠壁神经生长因子受体p75的表达及其意义

背景：神经生长因子（NGF）及其受体与肠神经系统关系密切，演剂结肠有肠壁神经丛损害，但NGF受体p75在泻剂结肠中的表达和作用尚不明确。目的：研究NGF受体p75在正常大鼠和泻剂结肠大鼠中的表达及其在泻剂结肠形成中的意义。方法：采用大黄和酚酞建立泻剂结肠大鼠模型，以墨汁推进试验测定其传输功能：采用免疫组化法对正常大鼠和泻剂结肠大鼠的结肠肠壁进行p75检测。观察其在肠壁中的分布和表达情况。结果：与对照组相比，模型组肠道传输功能明显减慢，大黄组和酚酞组黑染肠管长度和百分比（黑染肠管长度／肠管总长度）均较对照组显著减低（P〈0．01，P〈0．05）。p75存正常大鼠结肠黏膜下神经丛中呈阳性表达，在肌间神经丛中多呈弱阳性表达。大黄组中p75表达明显增强，黏膜下神经丛亦呈强阳性表达，与对照组相比有显著差异（P〈0．01）；肌间神经从中多呈阳性表达（P〈0．05）。酚酞组黏膜下神经丛呈阳性表达，肌间神绎丛3只呈阳性表达，余表现为弱阳性或阴性，与对照组相比无明显差异。结论：p75在泻剂结肠中的异常表达可能参与肠神经丛冲经元细胞的退化变性或凋亡．从而引起泻剂结肠的肠神经系统病理变化，进一步导致结肠动力异常。这种损害与长期应用刺激性泻剂有关。     

疏肝健脾方对腹泻型肠易激综合征大鼠的治疗作用及对肥大细胞、5-HT通路的影响

[目的]探讨疏肝健脾方对腹泻型肠易激综合征(diarrhea-predominant pattern irritable bowel syndrome,D-IBS)大鼠的治疗作用及肥大细胞、5-HT通路的影响。[方法]1日龄SD雄性大鼠随机分为正常组、模型组、疏肝健脾方组。采用母婴分离联合束缚应激方法建立D-IBS大鼠模型。造模成功后,疏肝健脾方组给予疏肝健脾方灌胃(2.33g·100g~(-1)·d~(-1)),正常组和模型组则给予等体积的生理盐水灌胃。灌胃结束后,测定各组大鼠粪便含水量、直结肠球囊扩张刺激时腹壁撤退反射(abdominal withdrawal reflex,AWR)评分及腹外斜肌肌电(electromyography,EMG)积分变化率。并分别采用甲苯胺蓝染色检测结肠肥大细胞表达,酶联免疫法(ELISA)测定结肠5-HT水平,蛋白免疫印记法(Western blot,WB)检测结肠5-HT3R(5-hydroxytryptamine receptor 3,5-HT3R)、5-HT4R(5-hydroxytryptamine receptor 4,5-HT4R)蛋白表达。[结果]疏肝健脾方组大鼠粪便含水量较模型组降低(P0.05);直结肠内球囊压力在40、60、80mmHg(1mmHg=0.133kPa)时,AWR评分及EMG积分变化率较模型组均降低(P0.05);疏肝健脾方组结肠肥大细胞数目、5-HT含量、5-HT3AR及5-HT3BR蛋白表达较模型组均降低(P0.05),5-HT4R蛋白表达较模型组升高(P0.05)。[结论]疏肝健脾方对D-IBS大鼠有较好治疗作用,其作用机制可能与降低结肠肥大细胞数目、5-HT的含量、5-HT3AR及5-HT3BR的表达,升高5-HT4R的表达有关。     

腹舒胶囊对大鼠慢传输型便秘的治疗作用

目的观察腹舒胶囊对便秘模型大鼠结肠肌间神经丛血管活性肠肽及P物质变化的影响,了解腹舒胶囊治疗慢传输型便秘的作用机制。方法随机分为正常对照组、大黄模型组、腹舒胶囊低剂量组、腹舒胶囊高剂量组、通便灵胶囊组、自然恢复组6组。观察腹舒胶囊对肠道传输功能、大鼠结肠壁病理组织学及结肠肌间神经丛血管活性肠肽(VIP)、P物质(SP)的影响。结果大黄模型组可见,黏膜慢性炎症;全层大量嗜酸性粒细胞浸润;肌间神经丛神经细胞空泡变性,减少。腹舒胶囊组肌间神经丛神经细胞空泡变性,减少;通便灵组、自然恢复组改善不明显。腹舒胶囊组VIP、SP免疫组化大黄模型组、通便灵组及自然恢复组均明显增高。结论腹舒胶囊可促进结肠肌间神经丛神经递质数量及功能恢复,可促进结肠肌间神经丛病理变化的恢复。     

肠易激综合征模型大鼠结肠肌间神经丛钙视网膜蛋白阳性神经元增加

目的检测肠易激综合征腹泻型(IBS-D)和便秘型(IBS-C)两种模型大鼠远端回肠、结肠黏膜下神经丛(SMP)和肌间神经丛(MP)钙视网膜蛋白(CALR)阳性神经元的变化,探讨其在IBS发病中的作用。方法分别采用慢急性联合应激、冰水灌胃法建立IBS-D和IBS-C大鼠模型,制作回肠和结肠SMP、MP全层铺片标本,免疫组织荧光双染法检测CALR阳性神经元的改变。结果与对照组相比,IBS-D和IBS-C模型大鼠回肠SMP、MP和结肠SMP中CALR阳性神经元比例的差异无统计学意义(P0.05),结肠MP中CALR阳性神经元的比例显著增加,分别为(17.2±3.2)%vs(13.4±2.9)%、(19.1±5.9)%vs(14.9±3.4)%,差异均有统计学意义(P0.05)。结论 IBS-D、IBS-C模型大鼠结肠MP中CALR阳性神经元增加可能参与IBS肠道敏感性增高。     

肠易激综合征模型大鼠5-羟色胺7受体的表达及作用

目的 观察5-羟色胺7受体在肠易激综合征(IBS)不同亚型模型大鼠大脑和消化道组织中表达和分布的差异,探讨其在IBS发病中的作用.方法 45只成年SD大鼠分均为对照组、腹泻型IBS(IBS-D)组和便秘型IBS(IB-C)组.乙酸加束缚应激法制备IBS-D模型,冰水灌胃法制备IBS-C模型.免疫组化法和实时定量PCR法检测各组大鼠大脑、空肠、回肠、近端结肠、远端结肠中5-HT7受体的分布及表达差异.放射免疫法测定以上各组织中环磷酸腺苷(cAMP)含量.结果 免疫组化结果 显示,IBS-C组和IBS-D组海马及下丘脑、IBS-C组回肠、近端结肠、远端结肠5-HT7受体表达强于对照组(P＜0.05).实时定量PCR结果 显示,IBS-C和IBS-D组海马和下丘脑、IBS-C组回肠、近端结肠及远端结肠5-HT7受体mRNA明显高于对照组(P＜0.05).IBS-C和IBS-D组海马和下丘脑、IBS-C组近端结肠和远端结肠cAMP含量显著高于对照组(P＜0.05).结论 两组大鼠脑组织及IBS-C大鼠结肠5-HT7受体表达及cAMP水平明显增高,可能与IBS-C胃肠动力障碍和内脏感觉异常有关.     

慢性胰腺炎大鼠肠运动功能和肌间神经丛NOS阳性神经元的变化

目的观察大鼠慢性胰腺炎时肠运动功能和肌间神经丛NOS阳性神经元的变化,探讨慢性胰腺炎大鼠肠动力障碍的可能机制。方法 SD雄性大鼠20只随机分为假手术组(n=10)和慢性胰腺炎组(n=10),用质量浓度为30 g/L TNBS乙醇盐溶液逆行胰胆管灌注制作慢性胰腺炎模型;假手术组注射等体积生理盐水。造模成功后胃内灌服质量浓度为10 g/L台盼蓝溶液,测定小肠推进比。取胰腺组织进行HE染色,观察病理变化。取末段回肠制作肌间神经丛全层标本,应用双重免疫荧光染色法观察肌间神经丛神经元,计算NOS阳性神经元占总神经元的百分比。结果假手术组肌间神经丛NOS阳性神经元的比例为(29.40±2.03)%,慢性胰腺炎组肌间神经丛NOS阳性神经元的比例为(39.62±1.75)%,两组比较,差异有统计学意义(P0.05)。慢性胰腺炎组大鼠小肠推进比显著降低[(49.70±3.74)%vs(31.14±3.23)%,P0.05]。NOS阳性神经元比例与小肠推进比呈负相关(r=-0.853,P0.05)。结论慢性胰腺炎大鼠存在肠动力障碍,同时回肠肌间神经丛NOS阳性神经元发生了重塑,慢性胰腺炎肠动力障碍可能与NOS抑制性神经元的表达上调相关。     

伴高脂血症急性坏死性胰腺炎大鼠胃肠传输与肠肌间神经丛形态改变研究

目的 探讨肠肌间神经丛形态改变与伴高脂血症急性坏死性胰腺炎(ANP)大鼠胃肠传输延迟的关系.方法 将40只雄性SD大鼠均分为4组(正常对照组、单纯ANP组、高脂对照组、高脂ANP组),分组采用高脂饲料喂养4周建立大鼠高脂血症模型,应用逆行胰胆管注射3.5%牛磺胆酸钠制作ANP大鼠模型.用墨汁灌胃法测量各组大鼠胃肠传输距离,计算胃肠传输率,以Karnovsky-Root直接法和NADPH组织化学法观察回肠肌间神经丛胆碱能和氮能神经的组织形态学改变.结果 高脂ANP组较单纯ANP组胰腺炎病理损伤加重(病理学评分12.8±0.63比10.8±1.93,P<0.01),胃肠传输明显延迟(传输率27%±5%比38%±6%,P<0.01),胆碱能神经元密度下降(4.80±1.23比5.80±0.79,P<0.05),氮能神经元密度明显升高(8.70±0.75比6.80±1.48,P<0.01).肌间神经丛乙酰胆碱脂酶和一氧化氮合酶改变与胃肠传输率有线性回归关系(R2=0.531,P<0.01).结论 伴高脂血症ANP的大鼠存在明显胃肠动力障碍,肠肌间神经丛形态改变与其密切相关.

Abstract：

Objective To explore association between the changes of myenteric nerve plexus and the delayed gastrointestinal transit in acute necrotic pancreatitis (ANP) rat complicated with hyperlipemia. Methods Atotal of 40 male Sprague-Dawley (SD) rats were randomly divided into 4 groups (normal control group, ANP group, hyperlipemia (HL) control group and HL with ANP group). HL rat model was established by fed with high-fat diet for 4 weeks, and ANP rat model was induced by retrograde injection of 3.5% sodium taurocholate into pancreatic duct. Gastrointestina1 transit distance was measured by ink gavage method. The histological changes of cholinergic and nitriergic nerves in myenteric plexus were observed by Karnovsky-Root method and NADPH histochemistry method. Results Pathological injuries were more severe in HL with ANP group than in ANP group (12.8±0.63 vs. 10.8±1.93,P<0.01), gastrointestinal transit was obviously delayed (transmission rate was 27%±5% vs. 38%±6%,P<0.01), the density of cholinergic neurons decreased (4.80±1.23 vs. 5.80±0.79, P<0.05), and the density of nitriergic neurons significantly increased (8.70±0.75 vs. 6.80±1.48, P<0.01). There was a linear regression between changes of cholinergic and nitrievgic nerves in myenteric nerve plexus and gastrointestinal transit (R2=0.531, P<0.01). Conclusion There was significant gastrointestinal motility disorder in the ANP rat complicated with hyperlipemia, which may be closely related with the changes of myenteric nerve plexus.     

增液汤对大鼠泻剂结肠治疗机制的研究

[目的]探讨增液汤对大黄总蒽醌引起大鼠"泻剂结肠"的治疗机制。[方法]实验分2期:第1期建立大鼠泻剂结肠模型;第2期增液汤对大鼠泻剂结肠的治疗作用;分别采用活性炭推进法检测肠道的推进功能、PGP9.5免疫组织化学染色法观察肌间神经元数量的变化和苏木精-伊红染色观察肠道病理改变,依此作为泻剂结肠模型的鉴定和增液汤疗效的观察。[结果]给予大黄总蒽醌灌胃3个月后,大鼠出现肠道推进功能明显减弱(P<0.01)、肌间神经元数目减少(P<0.05)以及黏膜下炎症细胞浸润,模型建立成功;模型治疗组加灌增液汤30d后,各项指标均有明显改善。[结论]增液汤能有效改善长期应用大黄总蒽醌引起的泻剂结肠模型大鼠的肠道传输功能,对肌间神经丛神经元的损伤具有一定的保护作用。增液汤对大黄总蒽醌引起的大鼠泻剂结肠具有治疗作用。     

Ligand-induced 5-HT3 receptor internalization in enteric neurons in rat ileum

BACKGROUND & AIMS: Release of 5-hydroxytryptamine (5-HT) from mucosal enterochromaffin cells and activation of 5-HT(3) receptors (5-HT(3)Rs) on neurons in the gut wall is important in the response of the gut to the luminal environment. Intestinal inflammation is associated with increased levels of mucosal 5-HT. The aims of the study were to determine the following: (1) if 5-HT(3)R undergoes ligand-induced internalization in myenteric neurons, and (2) the effect of long-term increase of mucosal 5-HT on 5-HT(3)Rs. METHODS: Acute effects of exogenous 5-HT or endogenous release of 5-HT by luminal glucose on cellular localization of 5-HT(3)Rs was determined by immunohistochemistry and confocal microscopy. Treatment with the serotonin re-uptake inhibitor, fluoxetine, for 6 days (20 mg/kg daily orally) was used to increase mucosal 5-HT chronically in rats. Net ileal fluid movement was measured in anesthetized rats by the weight change of a 2.5% agarose cylinder. RESULTS: Acute increases in 5-HT induced by exogenous or endogenous 5-HT decreased 5-HT(3)R immunoreactivity at the neuronal cell membrane by 70% and 60%, respectively. Chronic fluoxetine treatment increased mucosal levels of 5-HT and decreased membrane 5-HT(3)R immunoreactivity by 27%. Net fluid absorption was decreased by a 5-HT(3)R agonist or by luminal glucose; this was attenuated 88% and 99%, respectively, by fluoxetine treatment. CONCLUSIONS: Long-term increase in 5-HT in the intestinal mucosa results in increased 5-HT(3)R internalization in myenteric neurons. Chronic changes in mucosal 5-HT may alter gastrointestinal secretory and motor function via ongoing loss of receptor from neuronal membrane, causing a mismatch between luminal content and absorption.     

肠易激综合征患者小肠黏膜5-HT信号系统的研究

目的探讨肠易激综合征（IBS）患者不同部位小肠黏膜5-羟色胺（5-HT）水平及肠嗜铬细胞（EC细胞）数量是否改变。方法选取24例便秘型IBS（IBS-C）、26例腹泻型IBS（IBS-D）患者和26名健康人,行小肠镜及结肠镜检查并取十二指肠降段、近端空肠和回肠末段黏膜,用高压液相色谱-电化学法和免疫组织化学检测5-HT含量和EC细胞。结果IBSC患者近端空肠黏膜的5-HT含量与健康人相比有统计学意义（122±54ng／mg蛋白比188±91ng／mg蛋白,P〈0．05）,而十二指肠降段和回肠末段黏膜5-HT含量（182±90ng／mg蛋白、61±35ng／mg蛋白）与健康人相比（256±84ng／mg蛋白、93±45ng／mg蛋白）无统计学意义（P〉0．05）。IBS-D患者不同部位小肠黏膜5-HT含量与健康人相比均无统计学意义（P〉0．05）。IBS-C和IBSD患者不同部位小肠黏膜EC细胞数量与健康人相比均无统计学意义（P〉0．05）。结论上述结果提示1BS患者小肠黏膜5HT信号系统异常是其发病机制之-,但是在IBS-C和IBS-D之间有差异。     

大承气汤治疗大鼠实验性急性胰腺炎肠功能障碍的机制研究

目的 探讨大承气汤治疗大鼠实验性急性胰腺炎(AP)肠功能障碍的可能机制.方法 将72只成年SD大鼠随机分为假手术组(SO组)、胰腺炎组(AP组)和大承气汤治疗组,每组24只.经胆胰管内加压注射3.5%牛磺胆酸钠0.1 ml/100 g体重制备AP模型,治疗组在造模前给予大承气汤按2 g/100 g体重剂量灌胃1次,AP组和SO组则灌注等量0.9%氯化钠溶液.每组于造模后3、6、12 h各处死8只大鼠并立即心脏取血,检测血清淀粉酶水平,酶联免疫吸附试验检测血清5-羟色胺(5-HT)含量.同时取6 h时间点各组大鼠距屈氏韧带10 cm空肠、末端回肠及乙状结肠组织,采用RT-PCR和Western印迹法检测肠黏膜中5-HT_3、5-HT_4mRNA及蛋白表达情况.结果 ①造模后AP组和治疗组血清淀粉酶、5-HT水平均明显高于SO组(P<0.01),且每个时间点治疗组均较AP组显著降低(P<0.05);AP组和治疗组5-HT水平均呈现出先升后降趋势.②与SO组相比,AP组5-HT_3、5-HT_4mRNA及蛋白表达水平在空肠、末端回肠及乙状结肠均明显下降(P<0.01);与AP组比较,治疗组各部位5-HT_4mRNA及蛋白表达均增高(P<0.05),而5-HT_3 mRNA 及蛋白表达则未增加.结论 5-HT升高及其受体降低可能是AP发生肠功能障碍的原因之一,而大承气汤治疗的主要作用可能是通过增加5-HT_4表达以改善肠功能,可作为AP肠功能障碍的治疗方法之一.     

Immediate insulin treatment prevents gut motility alterations and loss of nitrergic neurons in the ileum and colon of rats with streptozotocin-induced diabetes

The streptozotocin-induced diabetic rat model was used to investigate the relation between the deranged gut motility and the segment-specific quantitative changes in the nitrergic myenteric neurons. Additionally, we studied the effectiveness of early insulin replacement to prevent the diabetes-induced changes. Rats were divided into three groups: controls, diabetics and insulin-treated diabetics. Ten weeks after the onset of diabetes, animals were chosen from each group for intestinal transit measurements. The remainder were killed and gut segments were processed for NADPH-diaphorase histochemistry and HuC/HuD immunohistochemistry. The diabetic rats displayed faster transit than that for the controls. In the insulin-treated group, the transit time was the same as that in the controls. In the duodenum of the diabetic rats, the number of nitrergic neurons was decreased, while the total neuronal number was not altered. In the jejunum, ileum and colon, both the total and the nitrergic neuronal cell number decreased significantly. Insulin treatment did not prevent the nitrergic cell loss significantly in the duodenum and jejunum, but it did prevent it significantly in the ileum and colon. These findings comprise the first evidence that the nitrergic neurons located in different intestinal segments exhibit different susceptibilities to a diabetic state and to insulin treatment.     

Enteric nerves in diabetic rats: increase in vasoactive intestinal polypeptide but not substance P

The distribution of vasoactive intestinal polypeptide (VIP) and substance P-like immunoreactivities was studied by immunohistochemistry in the myenteric plexus and circular muscle layer of the ileum and proximal colon of rats 8 wk after induction of diabetes with streptozotocin. A consistent increase was observed in fluorescence intensity of VIP-like immunoreactivity in the nerve fibers, and intensely stained cell bodies were significantly more frequent in the myenteric plexus of the ileum (p less than 0.001) from diabetic animals. Some varicosities of VIP-like immunoreactive fibers in the myenteric plexus appeared to be enlarged. Vasoactive intestinal polypeptide-like immunoreactivity was increased and VIP-like immunoreactive nerves appeared thicker in the circular muscle layer of both diabetic ileum and proximal colon. The VIP levels were measured biochemically in tissue consisting of the smooth muscle layers and myenteric plexus. A significant increase in the VIP content per centimeter of intestine was found in both the ileum (p less than and proximal colon (p less than 0.01) from diabetic rats. In contrast, no apparent change in substance P innervation was observed immunohistochemically in the myenteric plexus and circular muscle layer of either diabetic ileum or proximal colon when compared with controls. The results are discussed in relation to the symptoms of autonomic neuropathy of the gut in diabetes.     

胃起搏对大鼠胃窦肌间神经丛5-羟色胺能神经的影响

背景:胃起搏治疗胃动力障碍性疾病已引起广泛关注,但其作用机制尚不清楚。目的:观察胃起搏后胃窦肌间神经丛5-羟色胺(5-HT)能神经的活性变化,探讨胃起搏促胃动力作用的神经化学机制。方法:建立Wistar大鼠胃起搏模型,将大鼠分为起搏组(n=10)和对照组(n=6)。选用适宜的起搏参数以控制起搏组胃电慢波,1h后取胃窦组织,以免疫组化方法结合图像分析技术分析5-HT免疫反应阳性产物的分布、数量和免疫反应强度。结果:对照组大鼠5-HT免疫反应阳性神经纤维以肌间神经丛和节间束中稍多,神经节内阳性神经细胞体少见。起搏组大鼠胃窦组织5-HT免疫反应阳性神经纤维较对照组明显增多,神经节内阳性神经细胞体和带膨体的神经纤维也明显增多,免疫反应增强;肌间神经丛5-HT免疫反应阳性产物面积和平均光密度值均显著高于对照组(P<0.001)。结论:胃起搏后,胃窦肌间神经丛5-HT免疫反应阳性神经纤维和神经细胞体分布增多,5-HT能神经活性增强,表明5-HT能神经可能参与了胃起搏的促胃动力作用。     

Decreased expression of serotonin in the jejunum and increased numbers of mast cells in the terminal ileum in patients with irritable bowel syndrome

AIM： To investigate if there are changes in serotonin （5-HT） levels, enterochromaffin （EC） cells and mast cells in small intestinal mucosa of patients with irritable bowel syndrome （IBS）. METHODS： Diarrhea-predominant （IBS-D, n = 20）, or constipation-predominant （IBS-C, n = 18） IBS patients and healthy controls （n = 20） underwent colonoscopy and peroral small intestinal endoscopy, and mucosal samples were obtained at the descending part of the duodenum, proximal end of jejunum and terminal ileum. High-performance liquid chromatographyelectrochemistry and immunohistochemical methods were used to detect 5-HT content, EC cells and mast cells. RESULTS： （1） There were no differences in the number and distribution of EC cells between IBS patients and the normal group. （2） The mucosal 5-HT contents at the duodenum, jejunum and ileum in IBS-C patients were 182 ± 90, 122 ± 54, 61 ± 35 ng/mg protein, respectively, which were all lower than those in the normal group （256 ± 84, 188 ± 91, and 93 ± 45 ng/ mg protein, respectively）, with a significant difference at the jejunum （P 〈 0.05）. There were no differences in the small intestinal mucosal 5-HT contents between IBS-D patients and the normal group. The mucosal 5-HT contents at the duodenum were significantly higher than those at the ileum in the three groups （P 〈 0.001）. （3） The numbers of mast cells in patients with IBS-C and IBS-D at the ileum were 38.7 ± 9.4 and 35.8 ± 5.5/highpower field （hpf）, respectively, which were significantly more than that in the normal group （29.8 ± 4.4/hpf） （P 〈 0.001）. There was no significant difference in the numbers of mast cells at the other two parts between IBS patients and the normal group. The numbers of mast cells in IBS-C, IBS-D, and normal groups were all significantly higher at the ileum （38.7 ± 9.4, 35.8 ± 5.5, 29.8 ±4.4/hpf, respectively） than at the duodenum （19.6± 4.7, 18.5 ± 6.3, 19.2 ±3.3/hpf, respectively, P 〈 0.001）. CONCLUSIO