Sweet food improves chronic stress-induced irritable bowel syndrome-like symptoms in rats

AIM:To investigate whether palatable sweet foods have a beneficial effect on chronic stress-induced colonic motility and inflammatory cytokines.METHODS:Adult male rats were divided into 3groups:control(CON,n=5),chronic variable stress with chow(CVS-A,n=6),and chronic variable stress with chow and sweet food(CVS-B,n=6).The rats were fed standard rodent chow as the chow food and/or AIN-76A as the sweet food.A food preference test for AIN-76A was performed in another group of normal rats(n=10)for twelve days.Fecal pellet output(FPO)was measured for 6 wk during water bedding stress in the CVS groups.The weight of the adrenal glands,adrenocorticotropic hormone(ACTH)and corticosterone levels in plasma were measured.The expression levels of transforming growth factor-β,interleukin(IL)-2,and interferon-gamma(IFN-γ)were measured in the distal part of colonic tissues and plasma using Western blot analysis.RESULTS:In sweet preference test,all rats initially preferred sweet food to chow food.However,the consumption rate of sweet food gradually decreased and reduced to below 50%of total intake eight days after sweet food feeding.Accumulated FPO was higher in the CVS-A group compared with the CVS-B group over time.All stress groups showed significant increases in the adrenal to body weight ratio(CVS-A,0.14±0.01;CVS-B,0.14±0.01)compared with the control group(0.12±0.01,P<0.05).The plasma corticosterone and ACTH levels were significantly higher in the CVS-A(537.42±32.95,44.44±6.54 pg/mL)and CVS-B(655.07±30.82,65.46±4.44 pg/mL)groups than in the control group(46.96±13.29,8.51±1.35 pg/mL,P<0.05).Notably,the ratio of corticosterone to ACTH was significantly increased in the CVS-A group only.Rats exposed to CVS displayed significantly increased expression of IL-2 and IFN-γin the plasma and distal colon compared to the control group,whereas this effect was significantly attenuated in the CVS-B group.CONCLUSION:These results suggest that concurrent sweet food ingestion during CVS might have an effect on the reduction of stress-induced colonic hyper-motility and pro-inflammatory cytokine production in rats.

Study on the expression of Runx3 and TGF-β_1 protein in the colonic tissue from rats with irritable bowel syndrome

Objective:To investigate the expression of Runx3 and TGF-β1 protein in the colon from rats with irritable bowel syndrome（IBS）.Methods:Rat model for IBS was established by intracolonic instillation with acetic acid and restraint stress methods,which was confirmed by determinating the visceral sensitivity of the animals,including abdominal withdrawal reflex （AWR） score and the electronic behavior of the abdomen wall.The rats were randomly assigned into three groups:IBS,group（restraint stress,n=25）;IBS2 group（both instillation with acetic acid and restraint stress,n=25） and Control group（n=16）.The colonic tissue samples were collected for histological study and the expression of Runx3 and TGF-β1 proteins were detected by immunohistochemistry.Meanwhile,the relationship of these two proteins was calculated. Results:Visceral hypersensitivity（AWR and abdominal electrical activity） was significantly enhanced in IBS,and IBS2 groups than other groups.The colon tissue in all groups did not show any signs of inflammation.Furthermore,the expression of Runx3 and TGF-β1 protein in the colon from all groups show no significant difference（P】0.05）,with no remarkable relevancy between each other（P】0.05）.Conclusions:The rat model for IBS was successfully established. We did not find any significant changes in the expression of Runx3 and TGF-β1 protein in the colon tissue from IBS rats,suggesting that the quantitative changes may be not the way by which Runx3 and TGF-β1 protein play their roles in IBS.The accurate roles of Runx3 and TGF-β1 proteins in the pathogenesis of IBS remains to be further studied.

Key factors in developing the trinitrobenzene sulfonic acid-induced post-inflammatory irritable bowel syndrome model in rats

AIM:To investigate the key factors in developing the trinitrobenzene sulfonic acid(TNBS)-induced postinflammatory irritable bowel syndrome(PI-IBS)model in rats. METHODS:TNBS was administered to rats at the following conditions:(1)with different doses(20,10,5 mg/0.8 mL per rat);(2)with same dose in different concentrations(20 mg/rat,25,50 mg/mL);(3)in different ethanol percentage(25%,50%);and(4)at depth either 4 cm or 8 cm from anus.At 5 d and 4 wk after TNBS administration,inflammation severity and inflammation resolution were evaluated.At 4 and 8 wk after TNBS application,visceral hyperalgesia and enterochromaffin(EC)cell hyperplasia were assayed by abdominal withdrawal reflex test,silver staining and capillary electrophoresis. RESULTS:Our results showed that:(1)TNBS induced dose-dependent acute inflammation and inflammation resolution.At 5 d post TNBS,the pathological score and myeloperoxidase(MPO)activity in all TNBS treated rats were significantly elevated compared to that of the control(9.48±1.86,8.18±0.67,5.78± 0.77 vs 0,and 3.55±1.11,1.80±0.82,0.97±0.08 unit/mg vs 0.14±0.01 unit/mg,P<0.05).At 4 wk post TNBS,the pathological score in high and median dose TNBS-treated rats were still significantly higher than that of the control(1.52±0.38 and 0.80±0.35 vs 0,P<0.05);(2)Intracolonic TNBS administration position affected the persistence of visceral hyperalgesia.At 4 wk post TNBS,abdominal withdrawal reflex (AWR)threshold pressure in all TNBS-treated groups were decreased compared to that of the control(21.52 ±1.73 and 27.10±1.94 mmHg vs 34.44±1.89 mmHg,P<0.05).At 8 wk post TNBS,AWR threshold pressure in 8 cm administration group was still significantly decreased(23.33±1.33 mmHg vs 36.79±2.29 mmHg,P<0.05);(3)Ethanol percentage affected the TNBS-induced inflammation severity and visceral hyperalgesia.In TNBS-25%ethanol-treated group,the pathological score and MPO activity were significantly lowered compared to that of the TNBS-50%ethanoltreated group,while AWR threshold pressure were significantly elevated(36.33±0.61 mmHg vs 23.33±1.33 mmHg,P<0.05);and(4)TNBS(5 mg/0.8 mL per rat, in 50%ethanol,8 cm from anus)-treated rats recovered completely from the inflammation with acquired visceral hyperalgesia and EC cell hyperplasia at 4 wk after TNBS administration.CONCLUSION:TNBS dosage,concentration,intraco-lonic administration position,and ethanol percentage play important roles in developing visceral hyperalgesia and EC cell hyperplasia of TNBS-induced PI-IBS rats.

Epidermal growth factor upregulates serotonin transporter and its association with visceral hypersensitivity in irritable bowel syndrome

AIM: To investigate the role of epidermal growth factor(EGF) in visceral hypersensitivity and its effect on the serotonin transporter(SERT).METHODS: A rat model for visceral hypersensitivity was established by intra-colonic infusion of 0.5% acetic acid in 10-d-old Sprague-Dawley rats. The visceral sensitivity was assessed by observing the abdominal withdrawal reflex and recording electromyographic activity of the external oblique muscle in response to colorectal distension. An enzyme-linked immunosorbent assay was used to measure the EGF levels in plasma and colonic tissues. SERT mRNA expression was detected by real-time PCR while protein level was determined by Western blot. The correlation between EGF and SERT levels in colon tissues was analyzed by Pearson's corre-lation analysis. SERT function was examined by tritiated serotonin(5-HT) uptake experiments. Rat intestinal epithelial cells(IEC-6) were used to examine the EGF regulatory effect on SERT expression and function via the EGF receptor(EGFR).RESULTS: EGF levels were significantly lower in th rats with visceral hypersensitivity as measured in plas ma(2.639 ± 0.107 ng/mL vs 4.066 ± 0.573 ng/mL, < 0.01) and in colonic tissue(3.244 ± 0.135 ng/10 mg vs 3.582 ± 0.197 ng/100 mg colon tissue, P 0.01) compared with controls. Moreover, the EGF leve were positively correlated with SERT levels(r = 0.820 P < 0.01). EGF displayed dose- and time-dependen increased SERT gene expressions in IEC-6 cells. A EGFR kinase inhibitor inhibited the effect of EGF o SERT gene upregulation. SERT activity was enhance following treatment with EGF(592.908 ± 31.515 fmo min per milligram vs 316.789 ± 85.652 fmol/min pe milligram protein, P < 0.05) and blocked by the EGF kinase inhibitor in IEC-6 cells(590.274 ± 25.954 fmo min per milligram vs 367.834 ± 120.307 fmol/min pe milligram protein, P < 0.05).CONCLUSION: A decrease in EGF levels may contribute to the formation of visceral hypersensitivity through downregulation of SERT-mediated 5-HT uptake into enterocytes.

Effect of Herb-Partitioned Moxibustion on Structure and Functional Prediction of Gut Microbiota in Rats with Irritable Bowel Syndrome with Diarrhea

Objective:The objective of this study was to observe the effect of herb-partitioned moxibustion(HPM)on the gut microbiota of rats with diarrhea-predominant irritable bowel syndrome(IBS-D).Materials and Methods:A total of 48 male rats were randomly divided into a normal control group and an irritable bowel syndrome(IBS)model group.Using acetic acid irrigation and constraint stress,an IBS-D rat model was developed.After the model was made,the IBS rats were divided into IBS,HPM group,and pinaverium bromide(PB)group.The HPM received HPM for 20 min every day,while the PB was given gastric perfusion once a day for 14 days.After modeling and treatment,the abdominal withdrawal reflex,fecal character score,and fecal water content of rats were scored,and a 16S rRNA sequencing analysis was performed on the gut microbiota.Results:After treatment,the fecal character score and fecal water content in the HPM increased significantly,while visceral sensitivity decreased.Investigation of 16S rDNA sequencing revealed that α-diversity was reduced in the IBS,and HPM could increase the diversity of flora.The flora structure of IBS-D rats changed.HPM can increase the abundance of probiotics such as Akkermansia and reduce the abundance of opportunistic pathogens such as Bacteroides and Prevotella.Functional prediction analysis showed that the HPM was mainly related to the bacillary secret system,tricarboxylic acid cycle,and other pathways.Conclusion:HPM can regulate the gut microbiota of rats with IBS-D.

四神丸对腹泻型肠易激综合征大鼠5-HT信号通路表达的影响

目的通过研究四神丸对腹泻型肠易激综合征(IBS-D)模型大鼠5-羟色胺(5-HT)信号通路表达的影响,进一步揭示其治疗IBS-D的内脏敏感机制。方法SD大鼠32只,随机分为正常组、模型组、四神丸组和得舒特组,采用番泻叶灌胃联合避水应激法制备IBS-D大鼠模型,给药14d后进行Bristol粪便性状量表评分,依据腹壁撤退反射评定内脏疼痛阈值,ELISA法检测血清5-HT、SERT含量,免疫组化法检测结肠组织5-HT的阳性表达,Westernblotting法检测结肠组织5-HT4R的蛋白表达。结果与正常组比较,模型组大鼠Bristol粪便性状量表评分升高,内脏疼痛阈值降低,血清中5-HT含量增加、SERT含量减少,结肠组织中5-HT的阳性表达升高、5-HT4R的蛋白表达降低(P<0.05或P<0.01);与模型组比较,四神丸组大鼠Bristol粪便性状量表评分降低、内脏疼痛阈值升高,血清5-HT含量减少,SERT含量增加,结肠组织5-HT的阳性表达降低、5-HT4R的蛋白表达升高(P<0.05或P<0.01),且对5-HT、5-HT4R表达的影响四神丸组优于得舒特组(P<0.05)。结论四神丸治疗IBS-D的内脏敏感机制可能与调节5-HT信号通路的表达有关。

Effect of Electro-Acupuncture at Different Acupoints on Neuropeptide and Somatostatin in Rat Brain with Irritable Bowel Syndrome

Objective： To compare the regulatory effects of electro-acupuncture （EA） at acupoints Zusanli （ST36） and Hegu （LI4） on the visceral hyper-sensitivity in the rat model of irritable bowel syndrome （IBS）, and to explore the acting targets and specialty of acupoints. Methods： Except 8 rats of the normal control group, the rest 32 rats were prepared to set up the IBS models. IBS animal model was prepared by enema with acetic acid. Model rats were divided into three groups. Except for rats in the model group for control, those in the other two groups were treated 20 min by EA on ST36 （EA-ST36） and LI4 （EA-LI4） respectively for 2 weeks to observe the effect on behavior response of viscera sensitivity. The changes of neuropepUde （NPY）, the somatostatin （SS） levels in blood and tissues of brain and intestine were monitored as well. Results： The volume thresholds for abdomen uplifting and beck hunching were obviously increased after EA-ST36 （P〈0.05）, but showed insignificant change after EA-LI4. NPY contents lowered and SS contents increased in model rats; both EA-ST36 and EA-LI4 could raise the level of thalamic NPY （P〈0.01 and P〈0.05, respectively）, but showed insignificant effects on NPY in colonic tissue. As for SS content, its colonic level could be reduced by EA-S36 and EA-LI4 （P〈0.01 and P〈0.05, respectively）, however, its blood level was affected only by EA-ST36 （P〈0.05）. Conclusions： EA-ST36 or EA-LI4 could regulate the NPY in thalamus and SS in colonic tissue, the former could affect blood level of SS as well. It is deemed that NPY and SS may be the key substances for regulating the action of acupuncture in the braln-intastinal axis; their different levels could be regarded as an indicator for the functional differenca between the acupoints.

Visceral hypersensitivity and altered colonic motility after subsidence of inflammation in a rat model of colitis

AIM: Irritable bowel syndrome (IBS) is a functional bowel disorder characterized by visceral hypersensitivity and altered bowel motility. There is increasing evidence suggesting the role of inflammation in the pathogenesis of IBS, which addresses the possibility that formerly established rat model of colitis could be used as an TBS model after the inflammation subsided.METHODS: Colitis was induced by intracolonic instillation of 4 % acetic acid in male Sprague-Dawley rats. The extent of inflammation was assessed by histological examination and myeloperoxidase (MPO) activity assay. After subsidence of colitis, the rats were subjected to rectal distension and restraint stress, then the abdominal withdrawal reflex and the number of stress-induced fecal output were measured,respectively.RESULTS: At 2 days post-induction of colitis, the colon showed characteristic inflammatory changes in histology and 8-fold increase in MPO activity. At 7 days post-induction of colitis, the histological features and MPO activity returned to normal. The rats at 7 days post-induction of colitis showed hypersensitive response to rectal distension without an accompaning change in rectal compliance, and defecated more stools than control animals when under stress.CONCLUSION: These results concur largely with the characteristic features of IBS, visceral hypersensitivity and altered defecation pattern in the absence of detectable disease, suggesting that this animal model is a methodologically convenient and useful model for studying a subset of IBS.

电针单穴与腧穴配伍对肠易激综合征模型大鼠结肠功能的影响

目的通过对比观察电针单穴(上巨虚)和腧穴配伍(天枢+上巨虚)对便秘型肠易激综合征(IBS-C)模型大鼠结肠功能调整作用的差异性,初步探讨天枢配伍上巨虚是否有协同作用。方法选用Wistar大鼠90只,分为空白组(10只)和造模组(80只),造模组大鼠采用慢性和急性应激相结合方法连续干预10 d制备IBS-C模型;造模结束后,造模组大鼠通过腹壁撤回反射(AWR)半定量评分结合应激后大便颗粒数与空白组差异有统计学意义,以此筛选制备成功的模型,再随机分为模型组(10只)、上巨虚组(10只)、腧穴配伍组(10只);2个治疗组连续电针干预治疗14 d,对各组大鼠记录结肠痛敏阈值以及结肠肌电;采用酶联免疫吸附法检测各组大鼠血清中乙酰胆碱(ACh)含量;免疫蛋白印迹法检测近端结肠中胆碱乙酰转移酶(ChAT)蛋白表达。结果与空白组相比,模型组痛敏阈值降低(P<0.0001)、结肠慢波频率以及振幅均升高(P<0.001或P<0.01)、血清ACh含量以及近端结肠ChAT蛋白含量均降低(P<0.01);与模型组相比,电针干预治疗后,结肠痛敏阈值升高(P<0.0001)、结肠慢波频率以及振幅降低(P<0.05或P<0.01)、血清Ach含量以及近端结肠ChAT蛋白含量均升高(P<0.01或P<0.05)。结论电针单穴(上巨虚)和腧穴配伍(天枢+上巨虚)均能有效降低IBS-C模型大鼠内脏敏感性和调节结肠动力作用,但天枢配伍上巨虚并未显示明显腧穴配伍的优势和协同作用,针灸干预治疗IBS-C的腧穴配伍组方规律需进一步研究。

白芍总苷对腹泻型肠易激综合征大鼠5-HT信号通路的影响

目的:探讨白芍总苷对腹泻型肠易激综合征(diarrhea predominant irritable-bowel syndrome,IBS-D)大鼠5-羟色胺(5-hydroxytryptamine,5-HT)信号通路的影响。方法:选无特定病原体健康成年Wistar大鼠68只,雌雄各半,随机分为正常组13只和造模组55只。造模采用束缚联合慢性不可预见性刺激建立IBS-D大鼠模型,正常组大鼠正常饲养。将造模成功的52只大鼠随机分为模型组、匹维溴铵组及白芍总苷低、高剂量组,每组13只。模型组、正常组分别给予蒸馏水灌胃;匹维溴铵组给予匹维溴铵混悬液灌胃;白芍总苷低、高剂量组分别给予对应剂量白芍总苷溶液灌胃。各组大鼠均给药14天。检测比较各组大鼠粪便含水量,不同压力下腹壁撤退反射(abdominal withdrawal reflex,AWR)评分,结肠组织5-HT阳性细胞数及色氨酸羟化酶1(Tryptophan hydroxylase1,TPH-1)、5-羟色胺受体3(5-HT3 receptors,5-HT3R)、5-羟色胺转运蛋白(serotonin transporter,SERT)表达水平。结果:与模型组比较,各组大鼠粪便含水量较低,40 mm Hg(1 mm Hg≈0.133 kpa)、60 mm Hg压力下AWR评分较低,结肠组织5-HT阳性细胞数及TPH-1、5-HT3R表达水平较低,且白芍总苷低剂量组>白芍总苷高剂量组和匹维溴铵组,差异均有统计学意义(均P<0.05)。与模型组比较,各组大鼠结肠组织SERT表达水平较高,且白芍总苷低剂量组<白芍总苷高剂量组和匹维溴铵组,差异有统计学意义(P<0.05)。结论:白芍总苷能剂量依赖性地改善IBS-D大鼠腹泻症状,降低肠道敏感性,抑制结肠组织5-HT表达,其作用可能与调节5-HT信号通路中的TPH-1、5-HT3R、SERT表达有关。

电针足三里对肠易激综合征模型大鼠结肠慢波与整体自主神经平衡性的调控作用

目的观察单独电针足三里穴对肠易激综合征(IBS)模型大鼠结肠慢波放电与整体自主神经平衡性的调节作用,进一步了解单刺足三里穴治疗IBS的效应和机制。方法将36只雄性大鼠随机分为对照组、模型组、电针组,造模后每组选用7只。模型组、电针组大鼠采用避水应激法制作IBS疾病模型。电针组取双侧足三里,连续电针治疗14天,模型组和对照组仅每天在相同时间内进行抓取、固定,不做电针治疗。麻醉状态下记录心电图,记录心率的低频信号(LF)、高频信号(HF),并记录结肠电信号,均使用Powerlab数据采集分析系统进行记录。结果与对照组比较,模型组大鼠结肠慢波频率明显降低(P<0.05);与模型组比较,电针组大鼠结肠慢波频率升高(P<0.05)。与对照组比较,模型组大鼠的LF、LF/HF明显升高(P<0.05),HF明显降低(P<0.05);与模型组比较,电针组大鼠LF、LF/HF均明显降低(P<0.05),HF虽有升高趋势,但比较差异无统计学意义(P>0.05)。结论单独电针足三里穴对IBS模型大鼠的结肠运动功能可起到明显的改善作用,这一作用可能与改善了自主神经系统的平衡性有关。

电针不同穴位对腹泻型肠易激综合征大鼠不同肠道症状的比较性研究

目的观察电针合谷、天枢穴对腹泻型肠易激综合征(IBS-D)大鼠肠道痛敏和动力异常的影响,观察其疗效差异并探讨相关机制。方法新生Wistar大鼠随机分为正常组、模型组、合谷组和天枢组,每组10只。采用母婴分离、醋酸灌肠和结直肠扩张(CRD)联合制备IBS-D模型。第9周时,两穴位组分别对双侧合谷、天枢穴进行电针干预,隔日1次,每次20 min,共5次。通过Bristol便型分类法及腹部回撤反射法(AWR)进行肠道动力与敏感性的评估;通过免疫组化法检测结肠内肌层ICC特异性标志物C-kit与黏膜层5-HT3A受体的阳性表达。结果与正常组比较,模型组Bristol评分明显上升(P<0.01),潜伏期明显缩短、收缩波个数明显增多(P<0.01),肌层C-kit和结肠黏膜层5-HT3A受体的阳性表达均明显升高(P<0.01),说明IBS-D模型制备成功;与模型组比较,两穴位组的Bristol评分明显降低(P<0.01),且潜伏期明显增长、收缩波个数减少(P<0.01),肌层C-kit和结肠黏膜层5-HT3A受体表达明显降低(P<0.01);与合谷组比较,天枢组的大便评分明显降低(P<0.01),肌层C-kit表达降低(P<0.05),两组黏膜层5-HT3A受体的阳性表达无明显变化。结论电针合谷、天枢能有效调节IBS模型大鼠肠道痛敏和动力异常,两者对肠道痛敏症状的改善均有明显效果,电针天枢对IBS-D模型大鼠肠道痛敏和动力异常的调节作用明显优于合谷。

肝郁证便秘型肠易激综合征模型的建立与评价

目的采用单因素造模法和多因素联合造模法分别制备肝郁证便秘型肠易激综合征(IBS-C)大鼠模型,通过比较不同指标,提供理想的IBS-C实验动物模型。方法42只SD大鼠随机分为空白组(Normal组)、冰水灌胃组(Cold组)、束缚组(Restrain组)、夹尾组(Tail组)、冰水灌胃+束缚组(C+R组)和冰水灌胃+夹尾组(C+T组)。造模期间观测各组体重、进食量、饮水量和存活情况,进行旷场行为学、粪便Bristol评分、内脏敏感性、小肠推进等指标观测,HE染色观察大鼠结肠病理改变,ELISA法检测血清、结肠中5-HT、VIP含量。结果造模后,各模型组大鼠体重下降(P<0.05,P<0.01),进食量、饮水量减少,各模型组血清中的5-HT含量均有上升。其中Cold组排便粒数及Bristol得分减少,结肠5-HT含量增加(P<0.05,P<0.01);Restrain组旷场总路程及平均速度减少(P<0.01);Tail组糖水偏好降低(P<0.01);C+T组糖水偏好率、旷场总路程、小肠推进率、排便粒数及Bristol得分减少,结肠中5-HT含量增加,VIP含量减少(P<0.05,P<0.01);C+R组旷场总路程、平均速度、结肠中VIP含量减少(P<0.05);除Tail组,其余模型组与空白组相比,在造模7、14 d,各压力值下均出现内脏高敏感性(P<0.05,P<0.01);病理形态学观察显示,各模型组未见明显的炎性细胞浸润或病理学改变。结论采用冰水灌胃结合夹尾法可以成功建立肝郁证IBS-C大鼠模型,是5种方法中的首选,为系统深入研究中医药防治IBS-C机制奠定了基础。

肠激安方对腹泻型肠易激综合征模型大鼠T淋巴细胞和5-羟色胺的影响

【目的】观察肠激安方对腹泻型肠易激综合征(IBS)模型大鼠T淋巴细胞水平和5-羟色胺(5-HT)分泌的影响。【方法】选用新生SD大鼠46只,随机分成正常组,模型组,肠激安方低、中、高剂量组(中药低、中、高剂量组,剂量分别为0.94、1.88、3.76 g.kg-1.d-1),补脾益肠丸组(剂量为6.76 g.kg-1.d-1);采用直肠内醋酸刺激法复制肠道高敏感大鼠模型,经大鼠排便统计及肠道敏感性评估确认造模成功后,采用流式细胞术检测各组外周血CD3+、CD4+、CD8+T淋巴细胞亚群水平,采用免疫组化法观察各组大鼠肠组织5-HT阳性细胞数和免疫染色强度。【结果】模型组大鼠排便量显著增加,肠道敏感性显著升高,CD4+水平及CD4+/CD8+比值显著降低,CD8+水平显著升高,5-HT阳性细胞数及染色强度显著增加(均P<0.01);中药低、中、高剂量组可减少大鼠排便量(治疗第14天),降低肠道敏感性,升高CD4+水平及CD4+/CDS+比值,降低CD8+水平,减少5-HT阳性细胞数及染色强度(均P<0.01)。【结论】肠激安方治疗IBS的作用可能与改善细胞免疫功能和肠道敏感性,减少5-HT分泌有关。

慢性应激致肠易激综合征大鼠模型的建立与评价

目的建立一种模拟肠易激综合征临床症状的动物模型,为相关药物的研究提供实验基础。方法采用孤养附加慢性不可预见性刺激建立IBS模型,每只大鼠受到的刺激因子包括:24h禁水、24h禁食、昼夜颠倒、4℃冰水游泳15min、45℃高温5min、钳尾致痛1min、束缚制动5～8h、高速震荡15min等共8种,每种刺激因子出现5次,共40d。用腹部回撤反射压力阈值(AWR)和排便粒数检测动物的内脏感觉和胃肠运动功能变化;用敞箱行为评分和蔗糖水偏嗜度评价动物神经精神活动变化。结果造模2～3周腹部回撤反射压力阈值明显降低,排便粒数明显增加;造模3～4周模型组动物敞箱实验行为评分和蔗糖水偏嗜度明显降低。造模40d时,上述变化趋势仍存在。结论慢性应激加孤养可诱导动物胃肠运动亢进、内脏感觉致敏和神经精神活动的改变,模拟IBS患者的临床特征,可作为一种有效的IBS动物模型,用于评价相关药物。

肠易激综合征大鼠模型脊髓后角神经递质表达的改变

目的利用便秘型肠易激综合征(C-IBS)大鼠模型,对该模型中P物质(SP)、血管活性肠肽(VIP)、γ-氨基丁酸(GABA)、乙酰胆碱、去甲肾上腺素在脊髓后角的分布及表达进行研究,探讨IBS中脊髓后角神经系统在发病机制中的可能作用。方法采用以往本研究小组建立的C-IBS大鼠模型,取模型组及正常对照组大鼠的脊髓后角标本,进行常规组织固定、包埋、切片。分别应用抗SP、VIP、GABA、乙酰胆碱酯酶(AchE)、酪氨酸羟化酶(TH)抗体进行免疫组织化学染色,应用彩色病理图像分析系统对阳性表达的面积、不透光率密度值进行半定量分析。结果C-IBS大鼠模型脊髓后角中SP、AchE表达的阳性面积、不透光率密度值均明显增高(P<0.05);C-IBS大鼠模型脊髓后角中VIP、GABA、TH表达的阳性面积、不透光率密度值与正常对照组无显著差异(P>0.05)。结论C-IBS大鼠模型中脊髓后角SP及AchE表达具有改变,提示脊髓后角中P物质能及胆碱能神经系统可能参与C-IBS的病理生理过程。

肠易激综合征内脏感觉过敏大鼠脊髓诱发电位的研究

背景:内脏感觉过敏是肠易激综合征(IBS)的主要发病机制之一,临床上缺乏客观、无创的内脏敏感性检测方法。目的:建立直肠球囊扩张下脊髓诱发电位(SEP)的检测方法,并通过IBS内脏感觉过敏大鼠与正常大鼠的比较以及雌雄大鼠之间的比较,取得IBS存在内脏感觉过敏的客观证据。方法:通过直肠球囊有节律的充气、放气,给予直肠一定频率的反复刺激,记录诱发得到的脊髓相应节段(L6～S2)的SEP。结果:实验组雌雄大鼠分别与对照组同性别大鼠相比,SEP各波潜伏期显著缩短(P<0.05),峰间波幅显著增高(P<0.01)。实验组雌性大鼠的各波潜伏期显著短于雄性大鼠(P<0.05),峰间波幅也低于雄性大鼠(P<0.05);对照组雌性与雄性大鼠的各波潜伏期和峰间波幅无显著差异。结论:通过有节律的直肠球囊扩张,能诱发得到重复性好、易识别的SEP,可作为内脏敏感性的客观依据。

化学刺激引起的两种大鼠内脏高敏感性模型的建立

目的本文采用两种化学刺激建立两种新的大鼠内脏高敏感性肠易激综合征(IBS)模型。方法采用成年大鼠,经肠道连续6d给予冰醋酸或芥末油刺激后,进行直肠扩张,评估肠道敏感性,记录胃肠电频率、峰电位、峰峰值和面积,检测血清5-HT含量。结果与对照组相比,冰醋酸模型肠敏感性(P<0.05)、胃肠电频率(P<0.01)均升高;芥末油模型肠敏感性(P<0.01),胃肠电频率(P<0.01)、峰电位(P<0.05)、峰峰值(P<0.01)、峰面积(P<0.01),血清5-HT含量(P<0.05)均有变化,提示模型组敏感性增高。与模型组比较,反证药物组肠敏感性、胃肠电及血清5-HT含量均有一定恢复。结论通过对成年大鼠肠道进行化学刺激,成功建立了新的大鼠内脏高敏感性IBS模型。

痛泻要方及有效成分对肠易激综合征大鼠模型的治疗作用

目的观察痛泻要方及其有效成分对复合应激诱导的肠易激综合征(IBS)大鼠模型的治疗作用。方法应用新生鼠母子分离与避水应激复合方法建立IBS大鼠模型,观察药物对大鼠的止痛止泻作用。结果痛泻要方总挥发油、痛泻要方水提液可提高肠道扩张引起的腹壁收缩反射阈值,减少水应激诱导的排便粒数。结论痛泻要方总挥发油与水提液对IBS大鼠模型有明显的治疗效果,且总挥发油效果优于水提液。

戊己丸对炎症后肠易激综合征大鼠脑肠肽的调控作用

目的寻找诊断和治疗肠易激综合征(IBS)的生物学指标。方法采用乙酸加束缚应激法建立炎症后肠易激综合征(PI-IBS)动物模型;采用大鼠结肠运动指数(MI)、2 h内排出的粪粒数以及玻璃小球排出时间评价大鼠结肠的运动能力;观察PI-IBS模型大鼠的形成以及戊己丸对其的治疗作用;采用ELISA法检测PI-IBS大鼠脑和结肠组织中的降钙素基因相关肽(CGRP)、胃动素(MTL)、神经肽Y(NPY)、P物质(SP)、生长抑素(SS)、血管活性肠肽(VIP)、胆囊收缩素(CCK)水平。结果成功建立PI-IBS大鼠模型。模型大鼠体重降低;摄食量减少;排便量增多;出现稀便和无定形软便;自主运动量减少;结肠MI显著增加(P<0.05);大鼠排出的粪粒数显著增加(P<0.05);玻璃小球排出时间显著缩短(P<0.05)。戊己丸治疗7 d后能够明显改善以上症状。与正常对照组相比,PI-IBS大鼠脑组织中的CGRP、SS和VIP水平显著增加(P<0.05),NPY浓度显著降低(P<0.05);而戊己丸给药可以显著降低CGRP、SS和VIP浓度水平(P<0.05),显著升高NPY浓度水平(P<0.05)。与正常对照组相比,PI-IBS大鼠结肠组织中的CCK、NPY、MTL、SS和VIP均显著降低(P<0.05);戊己丸给药能够显著升高CCK和VIP水平(P<0.05)。结论戊己丸可通过调节IBS大鼠脑和结肠组织内多种脑肠肽的水平用来治疗IBS,这些可被调节的异常变化的脑肠肽可以成为潜在的诊断和治疗IBS的生物学指标。