vasoactive-intestinal-peptide and Irritable-Bowel-Syndrome

Traditional Chinese Medicine (TCM) serves as the most common alternative therapeutic approach for Western medicine and benefits IBS patients globally. Due to the lack of scientific evidence in the past, TCM formulas were not internationally well recognized as promising IBS remedies. In this review, firstly, we present the etiology and therapy of IBS in terms of traditional Chinese medical theory. Secondly, we summarize the clinical randomized controlled trials (RCTs) of TCM formulas for IBS patients that are available in the literature (from 1998 to September 2013), in which 14 RCTs conducted of high quality were discussed in detail. Of the 14 selected trials, 12 of those concluded that TCM formulas provided superior improvement in the global symptoms of IBS patients over the placebo or conventional medicines. As well, all 14 RCTs suggested that TCM formulas have good safety and tolerability. Last but not least, we explore the pharmacological mechanisms of the anti-IBS TCM formulas available in the literature (from 1994 to September, 2013). Collectively, in combating IBS symptoms, most TCM formulas exert multi-targeting actions including the regulation of neurotransmitters and hormones in the enteric nervous system (ENS), modulation of smooth muscle motility in the gastrointestinal (GI) tract, modulation of the hypothalamic-pituitary-adrenal (HPA) axis, attenuation of intestinal inflammation and restoration of intestinal flora, etc. In conclusion, TCM formulas appear to be promising for IBS treatment. This review provides a useful reference for the public in furthering a better understanding and acceptance of TCM formulas as IBS remedies.

Topics: Cholecystokinin; Drugs, Chinese Herbal; Gastrointestinal Motility; Humans; Hypothalamo-Hypophyseal System; Intestines; Irritable Bowel Syndrome; Medicine, Chinese Traditional; Muscle, Smooth; Neurotransmitter Agents; Nitric Oxide; Nitric Oxide Synthase Type II; Pituitary-Adrenal System; Randomized Controlled Trials as Topic; Serotonin; Signal Transduction; Somatostatin; Substance P; Vasoactive Intestinal Peptide

To compare the impacts of electroacu puncture (EA) and moxibustion (Mox) on the prima ry gastrointestinal symptoms and the expressions of colonic mucosa-associated neuropeptide substance P (SP) and vasoactive intestinal peptide (VIP) in patients with either diarrhea-predominant or constipation-predominant irritable bowel syndrome (IBS-D and IBS-C, respectively).. Eighty-five IBS patients were randomly allocated to the EA and Mox groups. Zusanli (ST 36) and Shangjuxu (ST 37) were selected as acupoints for electroacupuncture or warm moxibustion treatment once a day for 14 consecutive days. Before and after the treatment sessions, a Visual Analog Pain Scale and the Bristol Stool Form Scale were used to evaluate gastrointestinal symptoms. There were four dropout cases, leaving 81 participants (41 with IBS-D and 40 with IBS-C) who volunteered to undergo colonoscopy before and after the treatment sessions. During colonoscopy, sigmoid mucosa were collected to detect SP and VIP expression using immunohistochemistry assay.. Both EA and Mox treatments were effective at relieving abdominal pain in IBS-D and IBS-C patients. However, Mox was more effective at reducing diarrhea in IBS-D patients, whereas EA was more effective at improving constipation in IBS-C patients. EA and Mox treatments both down-regulated the abnormally increased SP and VIP expression in the colonic mucosa, with no significant difference shown between the two treatments.. Both EA and Mox treatments are effective at ameliorating gastrointestinal symptoms by reducing SP and VIP expression in the colonic mucosa of IBS patients.

Topics: Adolescent; Adult; Aged; Electroacupuncture; Female; Humans; Irritable Bowel Syndrome; Male; Middle Aged; Moxibustion; Substance P; Vasoactive Intestinal Peptide; Young Adult

Altered gut regulation, including motor and secretory mechanisms, is characteristic of irritable bowel syndrome (IBS). The severity of postprandial symptoms in IBS patients is associated with discomfort and pain; gas-related symptoms such as bloating and abdominal distension; and abnormal colonic motility. The aim of this study was to assess the postprandial response, i.e., gut peptide secretion and gastric myoelectric activity, in patients with constipation-predominant IBS. The study was conducted on 42 IBS patients (14 males, 28 females, mean age 45.1 ± 15.3 years) and 42 healthy participants (16 males, 26 females, mean age 41.1 ± 8.7 years). The study assessed plasma gut peptide levels (gastrin, CCK-Cholecystokinin, VIP-Vasoactive Intestinal Peptide, ghrelin, insulin) and gastric myoelectric activity obtained from electrogastrography (EGG) in the preprandial and postprandial period (meal-oral nutritional supplement 300 kcal/300 ml). Mean preprandial gastrin and insulin levels were significantly elevated in IBS patients compared to the control group (gastrin: 72.27 ± 26.89 vs. 12.27 ± 4.91 pg/ml; p < 0.00001 and insulin: 15.31 ± 12.92 vs. 8.04 ± 3.21 IU/ml; p = 0.0001), while VIP and ghrelin levels were decreased in IBS patients (VIP: 6.69 ± 4.68 vs. 27.26 ± 21.51 ng/ml; p = 0.0001 and ghrelin: 176.01 ± 88.47 vs. 250.24 ± 84.55 pg/ml; p < 0.0001). A nonsignificant change in the CCK level was observed. IBS patients showed significant changes in postprandial hormone levels compared to the preprandial state-specifically, there were increases in gastrin (p = 0.000), CCK (p < 0.0001), VIP (p < 0.0001), ghrelin (p = 0.000) and insulin (p < 0.0001). Patients with IBS showed reduced preprandial and postprandial normogastria (59.8 ± 22.0 vs. 66.3 ± 20.2%) compared to control values (83.19 ± 16.7%; p < 0.0001 vs. 86.1 ± 9.4%; p < 0.0001). In response to the meal, we did not observe an increase in the percentage of normogastria or the average percentage slow-wave coupling (APSWC) in IBS patients. The postprandial to preprandial power ratio (PR) indicates alterations in gastric contractions; in controls, PR = 2.7, whereas in IBS patients, PR = 1.7, which was significantly lower (p = 0.00009). This ratio reflects a decrease in gastric contractility. Disturbances in the postprandial concentration of gut peptides (gastrin, insulin and ghrelin) in plasma may contribute to abnormal gastric function and consequently intestinal motility, which are manifested in the intens

Topics: Adult; Cholecystokinin; Female; Gastrins; Gastrointestinal Hormones; Ghrelin; Humans; Insulins; Irritable Bowel Syndrome; Male; Middle Aged; Postprandial Period; Vasoactive Intestinal Peptide

Atractylodes lancea (Thunb.) DC. is a widely used traditional herb that is well known for treating spleen deficiency and diarrhea. According to traditional Chinese medicine (TCM) theory, diarrhea-predominant irritable bowel syndrome (IBS-D) is caused by cold and dampness, resulting in diarrhea and abdominal pain. Nevertheless, the effect and mechanism of Atractylodes on IBS-D are still unclear.. This study was designed to confirm the therapeutic effect of Atractylodes lanceolata oil (AO) in a rat model of IBS-D, and to determine the mechanisms by which AO protects against the disease.. The chemical components in AO were determined using gas chromatography-mass spectrometry (GC-MS). The expression levels of 5-hydroxytryptamine (5-HT), vasoactive intestinal peptide (VIP), and surfactant protein (SP) in serum and colon tissue were measured using enzyme-linked immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction (RT-PCR), western blotting (WB), immunohistochemistry (IHC), and immunofluorescence (IF) were used to elucidate the mechanism of action of AO toward inflammation and the intestinal barrier in a rat model of IBS-D.. The 15 chemical substances of the highest concentration in AO were identified using GC-MS. AO was effective against IBS-D in the rat model, in terms of increased body weight, diarrhea grade score, levels of interleukin-10 (IL-10), aquaporin 3 (AQP3), and aquaporin 8 (AQP8), and reduced fecal moisture content, levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), 5-HT, VIP, and SP, while also reducing intestinal injury, as observed using hematoxylin-eosin (HE) staining. In addition, the results indicated that AO increased the mRNA and protein expression levels of stem cell factor (SCF) and c-kit and enhanced the levels of zonula occludens-1 (ZO-1) and occludin, as well as decreased the levels of myosin light chain kinase (MLCK) and inhibited the phosphorylation of myosin light chain 2 (p-MLC2).. AO was found to be efficacious in the rat model of IBS-D. AO inhibited the SCF/c-kit pathway, thereby reducing inflammation and protecting against intestinal barrier damage via the MLCK/MLC2 pathway.

Topics: Animals; Aquaporins; Atractylodes; Colitis; Cytokines; Diarrhea; Intestinal Mucosa; Irritable Bowel Syndrome; Myosin Light Chains; Myosin-Light-Chain Kinase; Plant Oils; Proto-Oncogene Proteins c-kit; Rats, Sprague-Dawley; Serotonin; Signal Transduction; Stem Cell Factor; Tight Junction Proteins; Vasoactive Intestinal Peptide

Irritable bowel syndrome (IBS) is associated with intestinal dysbiosis and symptoms of IBS develop following gastroenteritis. We aimed to study the passage of live bacteria through the colonic epithelium, and determine the role of mast cells (MCs) and vasoactive intestinal polypeptide (VIP) in barrier regulation in IBS and healthy individuals.. Colon biopsies from 32 women with IBS and 15 age-matched healthy women (controls) were mounted in Ussing chambers; we measured numbers of fluorescently labeled Escherichia coli HS and Salmonella typhimurium that passed through from the mucosal side to the serosal side of the tissue. Some biopsies were exposed to agents that block the VIP receptors (VPAC1 and VPAC2) or MCs. Levels of VIP and tryptase were measured in plasma and biopsy lysates. Number of MCs and MCs that express VIP or VIP receptors were quantified by immunofluorescence. Biopsies from an additional 5 patients with IBS and 4 controls were mounted in chambers and Salmonella were added; we studied passage routes through the epithelium by transmission electron microscopy and expression of tight junctions by confocal microscopy.. In colon biopsies from patients with IBS, larger numbers of E coli HS and S typhimurium passed through the epithelium than in biopsies from controls (P < .0005). In transmission electron microscopy analyses, bacteria were found to cross the epithelium via only the transcellular route. Bacterial passage was reduced in biopsies from patients with IBS and controls after addition of antibodies against VPACs or ketotifen, which inhibits MCs. Plasma samples from patients with IBS had higher levels of VIP than plasma samples from controls. Biopsies from patients with IBS had higher levels of tryptase, larger numbers of MCs, and a higher percentage of MCs that express VPAC1 than biopsies from controls. In biopsies from patients with IBS, addition of Salmonella significantly reduced levels of occludin; subsequent addition of ketotifen significantly reversed this effect.. We found that colonic epithelium tissues from patients with IBS have increased translocation of commensal and pathogenic live bacteria compared with controls. The mechanisms of increased translocation include MCs and VIP.

Topics: Adult; Bacterial Translocation; Biopsy; Case-Control Studies; Colon; Dysbiosis; Electric Impedance; Escherichia coli; Female; Fluorescent Antibody Technique; Gastrointestinal Microbiome; Humans; Intestinal Mucosa; Irritable Bowel Syndrome; Mast Cells; Microscopy, Confocal; Microscopy, Electron, Transmission; Middle Aged; Receptors, Vasoactive Intestinal Peptide, Type II; Receptors, Vasoactive Intestinal Polypeptide, Type I; Salmonella typhimurium; Symbiosis; Tight Junctions; Vasoactive Intestinal Peptide; Young Adult

Chang-Kang-Fang formula (CKF), a multi-herb traditional Chinese medicinal formula, has been clinically used for treatment of irritable bowel syndrome (IBS). The mechanisms of CKF for treating IBS and the components that are responsible for the activities were still unknown.. To investigate the chemical profiles and effects of CKF on IBS model.. The chemical profiles of CKF were investigated by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS/MS). On colon irritation induced rat neonates IBS model, the influence of CKF on neuropeptides, including substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and 5-hydroxytryptamine (5-HT), were measured by ELISA, and the effect on intestinal sensitivity was assessed based on the abdominal withdrawal reflex (AWR) scores. In addition, the activities of CKF against acetic acid-induced nociceptive responses and prostigmin methylsulfate triggered intestinal propulsion in mice were also evaluated.. 80 components were identified or tentatively assigned from CKF, including 11 alkaloids, 20 flavanoids, 4 monoterpenoids, 9 iridoid glycoside, 9 phenylethanoid glycosides, 10 chromones, 7 organic acid, 3 coumarins, 2 triterpene and 5 other compounds. On IBS rat model, CKF was observed to reduce AWR scores and levels of SP, CGRP, VIP and 5-HT. Moreover, CKF reduced the acetic acid-induced writhing scores at all dosages and reduced the intestinal propulsion ration at dosage of 7.5 and 15.0g/kg/d.. CKF could alleviate the symptoms of IBS by modulating the brain-gut axis through increasing the production of neuropeptides such as CGRP, VIP, 5-HT and SP, releasing pain and reversing disorders of intestinal propulsion. Berberine, paeoniflorin, acteoside, flavonoids and chromones may be responsible for the multi-bioactivities of CKF.

Topics: Acetic Acid; Animals; Calcitonin Gene-Related Peptide; Colon; Drugs, Chinese Herbal; Irritable Bowel Syndrome; Male; Mice; Phytochemicals; Rats, Sprague-Dawley; Serotonin; Substance P; Vasoactive Intestinal Peptide; Visceral Pain

Previous studies have revealed that mast cells (MCs) may activate the protease-activated receptors and release of neuropeptides involved in the pathogenesis of irritable bowel syndrome (IBS). The levels of proteaseactivated receptor 2 (PAR-2) and tryptase can contribute to understanding the pathogenesis of IBS.. Colonoscopic biopsies were performed of 38 subjects (20 with IBSdiarrhea [IBS-D], eight with IBS-constipation [IBS-C], and 10 healthy volunteers). The mRNA and protein levels of tryptase and PAR-2 were assessed by real-time PCR and Western blot. The levels of vasoactive intestinal peptide (VIP), substance P (SP), and calcitonin gene-related peptide (CGRP) were measured by immunohistochemistry, and MCs were counted by toluidine blue staining.. Significant increases in the mRNA expression of tryptase (p<0.05, IBS-D, IBS-C vs control) and PAR-2 (p<0.05, IBS-D, IBS-C vs control) and in the tryptase protein level (p<0.05, IBS-D, IBS-C vs control) were detected in IBS. Elevations of MCs, CGRP, VIP and SP (p<0.05, IBS-D vs control) were observed for IBS-D only.. Tryptase levels may upregulate the function of PAR- 2, resulting in the release of neuropeptide and they were correlated with clinical symptoms associated with IBS.

Topics: Abdominal Pain; Adult; Calcitonin Gene-Related Peptide; Case-Control Studies; Colon; Female; Humans; Irritable Bowel Syndrome; Male; Mast Cells; Middle Aged; Receptor, PAR-2; RNA, Messenger; Substance P; Tryptases; Vasoactive Intestinal Peptide

To investigate the vasoactive intestinal peptides (VIP) expression in irritable bowel syndrome (IBS) and trinitrobenzene sulfonic acid (TNBS) induced colitis.. The VIP gene expression and protein plasma levels were measured in adult participants (45.8% male) who met Rome III criteria for IBS for longer than 6 mo and in a rat model of colitis as induced by TNBS. Plasma and colons were collected from naïve and inflamed rats. Markers assessing inflammation (i.e., weight changes and myeloperoxidase levels) were assessed on days 2, 7, 14 and 28 and compared to controls. Visceral hypersensitivity of the rats was assessed with colo-rectal distension and mechanical threshold testing on hind paws. IBS patients (n = 12) were age, gender, race, and BMI-matched with healthy controls (n = 12). Peripheral whole blood and plasma from fasting participants was collected and VIP plasma levels were assayed using a VIP peptide-enzyme immunoassay. Human gene expression of VIP was analyzed using a custom PCR array.. TNBS induced colitis in the rats was confirmed with weight loss (13.7 ± 3.2 g) and increased myeloperoxidase activity. Visceral hypersensitivity to colo-rectal distension was increased in TNBS treated rats up to 21 d and resolved by day 28. Somatic hypersensitivity was also increased up to 14 d post TNBS induction of colitis. The expression of an inflammatory marker myeloperoxidase was significantly elevated in the intracellular granules of neutrophils in rat models following TNBS treatment compared to naïve rats. This confirmed the induction of inflammation in rats following TNBS treatment. VIP plasma concentration was significantly increased in rats following TNBS treatment as compared to naïve animals (P < 0.05). Likewise, the VIP gene expression from peripheral whole blood was significantly upregulated by 2.91-fold in IBS patients when compared to controls (P < 0.00001; 95%CI). VIP plasma protein was not significantly different when compared with controls (P = 0.193).. Alterations in VIP expression may play a role in IBS. Therefore, a better understanding of the physiology of VIP could lead to new therapeutics.

Topics: Adult; Animals; Biomarkers; Case-Control Studies; Colitis; Colon; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Hyperalgesia; Inflammation Mediators; Irritable Bowel Syndrome; Male; Middle Aged; Pain Threshold; Peroxidase; Pilot Projects; Rats, Sprague-Dawley; RNA, Messenger; Signal Transduction; Time Factors; Trinitrobenzenesulfonic Acid; Vasoactive Intestinal Peptide; Visceral Pain; Weight Loss; Young Adult

The aim of this study was to investigate the mechanism (s) of action of gastrointestinal hormones in the pathogenesis of irritable bowel syndrome (IBS), and the correlation between gastrointestinal hormones and psychological factors. Patients with IBS were divided into IBS with normal emotional state ratings and IBS in anxiety-depressive states groups. The two groups were then subdivided into IBS-constipation predominant (IBS-C) and IBS-diarrhea predominant (IBS-D) groups. Non-IBS patients with normal depression and anxiety ratings were recruited as controls. The expression of somatostatin (SS) and vasointestinalpeptid (VIP), motilin in the colonic mucosa was detected by immunohistochemistry and radioimmunoassay. The anxiety-depression scores of patients with IBS were significantly different from those of the control group. The expression levels of SS and VIP, motilin colonic mucosa of the patients with IBS were higher compared with those of the control.group. Furthermore, the expression level of SS in the IBS-C group demonstrated a significantly larger increase than that in the IBS-D group; however, there was no significant difference in the expression of VIP between the IBS-C and IBS-D groups. In addition, the expression levels of SS and VIP, motilin in the IBS groups with normal emotional state ratings were notably different from those in the IBS groups in anxiety-depressive states. Anxiety-depressive states may lead to changes in the secretion of SS and VIP, motilin, and subsequently to changes in gastrointestinal motility and function.

Topics: Adolescent; Adult; Anxiety Disorders; Colon; Depression; Female; Gastrointestinal Motility; Gene Expression Regulation; Humans; Intestinal Mucosa; Irritable Bowel Syndrome; Male; Middle Aged; Motilin; Neurosecretory Systems; Somatostatin; Vasoactive Intestinal Peptide

Recent studies have shown that mast cells play an important role in irritable bowel syndrome (IBS). We investigated the relationship between mast cells and the gut hormones substance P and vasoactive intestinal peptide (VIP) in irritable bowel syndrome with diarrhea (IBS-D).. Colonoscopic biopsies were performed on the rectal mucosa of 43 subjects (IBS-D patients: 22, healthy volunteers: 21) diagnosed according to the Rome III criteria. Mast cells, and substance P & VIP were evaluated by quantitative immunohistology and image analysis. Mast cells were counted as tryptase-positive cells in the lamina propria, and substance P and VIP levels were expressed as percentages of total areas of staining.. Mast cell counts were higher in IBS-D patients than healthy volunteers (9.6 ± 3.3 vs. 5.7 ± 2.5/high power field (HPF), p < 0.01). Substance P was also elevated (0.11 ± 0.08% vs. 0.03 ± 0.02 %, p < 0.01) while VIP was only high in women with IBS-D. Mast cell counts were positively correlated with levels of substance P & VIP in women but not men (women: r = 0.625, p < 0.01 for substance P and r = 0.651, p < 0.01 for VIP). However, mast cell counts were not correlated with IBS symptoms including abdominal pain.. Mast cells are activated leading to the raised levels of substance P & VIP in IBS-D patients. However, the correlation between mast cells and levels of substance P & VIP differs according to gender.

Topics: Adolescent; Adult; Aged; Case-Control Studies; Cell Count; Diarrhea; Female; Humans; Intestinal Mucosa; Irritable Bowel Syndrome; Male; Mast Cells; Middle Aged; Rectum; Sex Factors; Substance P; Vasoactive Intestinal Peptide; Young Adult

To explore the point specificity of eye-acupuncture and the mechanism of eye-acupuncture on diarrhea-predominant irritable bowel syndrome (D-IBS).. Forty male Wistar rats of SPF grade were randomly divided into a normal group, a model group, a eye-acupuncture point (AA) group and a non-point (NA) group. The D-IBS rat model was established with the combination methods of the chronic stress and binding limbs. The AA group was treated by acupuncture at "low energizer area", "large intestine area", "liver area" and "spleen area", and the NA group by acupuncture at 3 mm apart from the same points area mentioned above, and the normal group and the model group with no intervention. The rate of feces moisture content was detected. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA of aquaporin 8 (AQP 8) in colon. Protein expressions of the vasoactive intestinal peptide (VIP) and AQP 8 in colon were detected by SABC immunohistochemistry method.. Compared with normal group, the rate of feces moisture content at the 18th and 25th days, VIP protein in colon mucosa, myenteric nerve plexus and hypo-mucosa nerve plexus increased significantly (all P < 0.01), and AQP 8 mRNA in colon mucosa decreased significantly in model, AA and NA group (P < 0.05, P < 0.01); AQP 8 protein in colon mucosa decreased significantly in model group and NA group (both P < 0.01). Compared with model group, the rate of feces moisture content at the 25th day and VIP protein in colon mucosa decreased significantly (P < 0.01, P < 0.05), and AQP 8 mRNA and protein increased significantly (P < 0.05, P < 0.01) in AA group. Compared with AA group, the rate of feces moisture content at the 25th day and VIP protein in colon mucosa increased significantly (both P < 0.01), and AQP 8 mRNA and protein decreased significantly (both P < 0.01) in NA group.. Eye-acupuncture has a good therapeutic effect on D-IBS. It is suggested that one of the mechanism is relate to increase AQP 8 in colon tissue and restrain the expression of VIP. Non-point area of eye-acupuncture has no obviously therapeutic effect and so to illustrate the point specificity of eye-acupuncture.

Topics: Acupuncture Points; Acupuncture Therapy; Animals; Aquaporins; Colon; Diarrhea; Humans; Irritable Bowel Syndrome; Male; Rats; Rats, Wistar; Vasoactive Intestinal Peptide

To observe the effect of the eye-acupuncture therapy on serum and colonic substance P (SP) and vasoactive intestinal peptide (VIP) contents in rats with irritable bowel syndrome (IBS) so as to explore its underlying mechanism.. Forty male Wistar rats were equally randomized into control group, IBS model group, eye-acupuncture group and medication (Pinaverium bromide, 7.5 mg/kg, twice daily, intragastric administration) group. IBS model was established by giving the rat with chronic stress stimulation (cold-water swimming, tail clamping, electrical shock, etc.) for 18 days. Eye-acupuncture of Xiajiao (Low Energizer) Area, Pi (Spleen) Area, Gan (Liver) Area and Dachang (Large Intestine) Area was given to the rat 20 min, twice daily for 7 d. Histopathological changes of the colon tissue were displayed by HE staining; and serum and colonic SP and VIP contents were detected by enzyme linked immunosorbent assay (ELISA).. No significant difference was found among 4 groups in the histopathological changes of the colon. In comparison with normal control group, both serum and colonic SP and VIP contents in model group increased significantly (P < 0.01), while compared with model group, those in eye-acupuncture and medication groups lowered considerably (P < 0.01).. Eye-acupuncture can reduce serum and coIonic SP and VIP contents in IBS rats, which may play a role in relieving IBS in eye-acupuncture clinic.

Topics: Acupuncture Therapy; Animals; Colon; Disease Models, Animal; Eye; Humans; Irritable Bowel Syndrome; Male; Random Allocation; Rats; Substance P; Vasoactive Intestinal Peptide

The cellular mechanisms of motility dysfunction in postinfectious irritable bowel syndrome (PI-IBS) are not known. We used a rat model of neonatal inflammation to test the hypothesis that gene plasticity in colonic circular smooth muscle cells underlies motility dysfunction in PI-IBS. Mild/moderate or severe inflammation was induced in neonatal and adult rats. Experiments were performed in tissues obtained at 7 days (short term) and 6-8 wk (long term) after the induction of inflammation. Severe inflammation in neonatal rats induced persistent long-term smooth muscle hyperreactivity to acetylcholine (ACh), whereas that in adult rat caused smooth muscle hyporeactivity that showed partial recovery in the long term. Mild/moderate inflammation had no effect in neonatal rats, but it induced smooth muscle hyporeactivity to ACh in adult rats, which recovered fully in the long term. Smooth muscle hyperreactivity to ACh resulted in accelerated colonic transit and increase in defecation rate, whereas hyporeactivity had opposite effects. Smooth muscle hyperreactivity to ACh was associated with increase in transcription rate of key cell-signaling proteins of the excitation-contraction coupling alpha1C subunit of Cav1.2 (L-type) calcium channels, Galphaq, and 20-kDa myosin light chain (MLC20), whereas hyporeactivity was associated with their suppression. Inflammation in adult rats induced classical inflammatory response, which was absent in neonatal rats. Severe neonatal inflammation enhanced plasma norepinephrine and muscularis propria vasoactive intestinal polypeptide in the long term. We conclude that severe, but not mild/moderate, inflammation in a state of immature or impaired stress and immune response systems alters the transcription rate of key cell-signaling proteins of excitation-contraction coupling in colonic circular smooth muscle cells to enhance their contractility and accelerate colonic transit and defecation rate.

Topics: Acetylcholine; Age Factors; Animals; Animals, Newborn; Calcium Channels, L-Type; Cholinergic Agents; Colon; Defecation; Disease Models, Animal; Enteric Nervous System; Enteritis; Gastrointestinal Motility; Gene Expression Regulation; GTP-Binding Protein alpha Subunits, Gq-G11; Inflammation Mediators; Irritable Bowel Syndrome; Male; Myocytes, Smooth Muscle; Myosin Light Chains; Rats; Rats, Sprague-Dawley; Severity of Illness Index; Signal Transduction; Vasoactive Intestinal Peptide

Topics: Antineoplastic Agents, Hormonal; Diagnosis, Differential; Diarrhea; Female; Humans; Hypokalemia; Indium Radioisotopes; Irritable Bowel Syndrome; Liver; Liver Neoplasms; Middle Aged; Octreotide; Pancreatic Neoplasms; Radionuclide Imaging; Tomography, X-Ray Computed; Vasoactive Intestinal Peptide; Vipoma

Irritable bowel syndrome (IBS) is a functional bowel disorder which is characterized by abdominal pain and disturbed bowel habits. The pathophysiological mechanism is complex and still remains incompletely clear. Alterations at both the central and the peripheral level are thought to contribute to the symptoms of IBS, including psychosocial factors, visceral hypersensitivity and abnormal gastrointestinal motility and secretion. Several gut peptides contribute to the regulation of gastrointestinal function, but little is known about gut hormone secretion in IBS.. We evaluated the concentrations of cholecystokinin (CCK), vasoactive intestinal peptide (VIP), somatostatin, substance P, neuropeptide Y (NPY) in plasma and in sigmoid tissue in 40 patients with IBS and 15 age- and gender-matched controls by using radioimmunoassay.. IBS patients had higher plasma level of CCK (p < 0.01), and the level of CCK in the sigmoid was also increased compared with controls (p < 0.05). The levels of somatostatin and substance P in fasting plasma and in the sigmoid were not different between IBS patients and control subjects (p > 0.05), but the levels of VIP in sigmoid tissue or in plasma were higher in IBS patients than in control group (p < 0.01). The NPY levels in both plasma and the sigmoid were significantly lower in IBS patients than in controls (p < 0.05). Plasma NPY level in patients with IBS with diarrhea as a predominant bowel pattern was lower than in patients with IBS with constipation as a predominant bowel pattern.. IBS patients have increased levels of CCK and VIP and decreased NPY levels in fasting plasma and sigmoid tissue. These alterations of VIP, CCK and NPY may play a role in the pathogenesis of IBS.

Topics: Adult; Aged; Cholecystokinin; Female; Gastrointestinal Hormones; Humans; Irritable Bowel Syndrome; Male; Middle Aged; Neuropeptide Y; Somatostatin; Substance P; Vasoactive Intestinal Peptide

The efficacy of electroacupuncture (EA) for treating patients with diarrhea-predominant IBS has been confirmed in the authors' former research, but the regulatory mechanism of EA in IBS is still unknown. The aim of this study was to explore the relationship between the effect of EA on treating IBS rats and the activation and proliferation of mast cell (MC), the secretion of substance P(SP), and vasoactive intestinal polypeptide (VIP). The IBS rat model was set up with stress of binding limbs and colorectal distention. All rats were randomly assigned to four groups (Normal, Model, Tegaserod and EA). Hematoxylin and eosin staining has been used to observe the pathological change in the rats' colonic mucosa and an AWR scoring system has been applied to evaluate improvement of visceral hypersensitivity in various methods of the different groups. Toluidine blue improved method (TBI) and immunohistochemistry have also been involved in observations of mucous mast cells in the colon, change of c-fos positive cells, and secretion of SP, SPR, VIP, VIPR in the local colon. Firstly, the threshold of visceral sensitivity in the rats model with IBS was remarkably reduced (P < 0.01). The MC count in colonic mucosa and c-fos positive cells count increased significantly (P < 0.01) with positive correlation within each. Secondly, EA on ST-25 and Tegaserod pouring into the stomach can inhibit the proliferation and activation of MC in the colon and regulate secretion of SP, SPR, VIP, VIPR (P < 0.01, P < 0.05), while the effect of EA is obviously superior to Tegaserod. We concluded, firstly, that the abnormal proliferation and activation of mucous mast cells in the colon, and oversecretion of neuropeptides such as SP, VIP and their receptors could be one of key mechanisms of etiology of IBS. Secondly, the inhibition of activation and proliferation and the secretion of SP, VIP could be major effects of EA when treating rats with IBS.

Topics: Animals; Electroacupuncture; Immunohistochemistry; Indoles; Irritable Bowel Syndrome; Male; Mast Cells; Rats; Rats, Sprague-Dawley; Substance P; Vasoactive Intestinal Peptide

The aim was to assess the roles of gut hormones and immune dysfunction in irritable bowel. In Study I, rectal mucosal samples examined blindly showed no histological evidence of inflammation in 16 irritable bowel patients compared to 17 healthy controls. The proinflammatory mediators interleukin-1beta and prostaglandin E2 also failed to show evidence of inflammation. Vasoactive intestinal peptide was elevated in irritable bowel (P = 0.01), but substance P, calcitonin gene-related peptide, and somatostatin levels were similar to control values. In Study II, 30 irritable bowel patients had elevated (P = 0.002) plasma concentrations of vasoactive intestinal peptide compared to 30 controls, and peptide levels were unrelated to whether the patient's predominant bowel habit was constipation, diarrhea, or both in alternation. In conclusion, no evidence of inflammation was detected in irritable bowel patients, but elevated vasoactive intestinal peptide concentrations were observed in both studies and might represent a potential diagnostic tool for irritable bowel syndrome.

Topics: Adult; Blotting, Western; Calcitonin Gene-Related Peptide; Dinoprostone; Female; Humans; Immunoassay; Interleukin-1; Intestinal Mucosa; Irritable Bowel Syndrome; Male; Somatostatin; Substance P; Vasoactive Intestinal Peptide