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OBJECTIVES: Abnormal motility of the residual colon has been reported in post-pull-through Hirschsprung disease (PT-HSCR) patients with persistent defecation problems. We reviewed the role of colonic manometry (CM) in the management of defecation disorders in these patients. METHODS: We retrospectively reviewed the medical record of PT-HSCR children who underwent CM for persistent symptoms of abnormal defecation. We reviewed their clinical course and its relation to CM findings. RESULTS: Thirty PT-HSCR patients underwent CM, of which five were diagnosed with transition zone pull-through and were excluded. Of the remaining 25 patients, 16 had colonic dysmotility, 8 had normal CM, and one had colonic hypermotility. In patients with dysmotility, five responded to ongoing medical management, three required surgical intervention (ileostomy), three remained symptomatic with medical management but not yet received surgical intervention, and five were lost to follow-up. In patients with normal CM, four responded to ongoing medical therapy, two required additional surgery (antegrade enema procedure), and two were lost to follow-up. The patient with hypermotility improved with adding loperamide. CONCLUSIONS: Colonic dysmotility can occur in PT-HSCR patients with persistent defecation problems. CM was helpful in delineating the degree of colonic neuromuscular dysfunction. CM results were used in conjunction with other clinical data to determine optimal management. Our findings support that medical management should first be optimized before consideration of colonic manometry and surgical interventions.
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Colo , Motilidade Gastrointestinal , Doença de Hirschsprung , Manometria , Humanos , Doença de Hirschsprung/cirurgia , Doença de Hirschsprung/fisiopatologia , Manometria/métodos , Estudos Retrospectivos , Colo/fisiopatologia , Colo/cirurgia , Feminino , Masculino , Lactente , Pré-Escolar , Criança , Defecação , Constipação Intestinal/fisiopatologia , Constipação Intestinal/etiologiaRESUMO
This work aims to investigate the effects and mechanism of emodin in treating diabetic gastroenteropathy and colonic dysmotility in STZ + HS/HF diet induced diabetic gastroenteropathy rats. Diabetic colonic dysmotility model was established by high-fat/high-glucose (HS/HF) feeding combined with streptozotocin (STZ). Emodin was divided into high, medium and low dose groups. After eight weeks of intervention, fasting blood glucose (FBG) and body weight were measured. Gastrointestinal transmission time was evaluated. Serum vasoactive intestinal peptide (VIP) and substance P (SP) were detected. Colonic protein expression of selective autophagy adaptor proteins p62 and beclin1 were detected by immunohistochemistry. Colonic protein expression of beclin1, autophagy related gene 5 (Atg5), C-kit and p62 were detected by Western blot. After treating with emodin, gastrointestinal transmission rate was improved. The expression of serum SP was increased and serum VIP was decreased. Colonic c-kit and p62 were up-regulated. The expressions of beclin1 and Atg5 were down-regulated. Emodin can improve colonic dysmotility and promote the recovery of colonic motility and intestinal defecation in diabetic rats. Its mechanism may involved with up-regulating the expression of C-kit and P62, down-regulating the expression of Beclin1 and Atg5 in colon, which are associated with colon over-autophagy of Cajal interstitial cell (ICC).
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Diabetes Mellitus Experimental , Emodina , Células Intersticiais de Cajal , Ratos , Animais , Células Intersticiais de Cajal/metabolismo , Emodina/farmacologia , Emodina/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Proteína Beclina-1/metabolismo , Autofagia , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Proteínas Proto-Oncogênicas c-kit/farmacologia , Receptores Proteína Tirosina Quinases/metabolismoRESUMO
Angiotensin II (Ang II) regulates colon contraction, acting not only directly on smooth muscle but also indirectly, interfering with myenteric neuromodulation mediated by the activation of AT1 /AT2 receptors. In this article, we aimed to explore which mediators and cells were involved in Ang II-mediated colonic contraction in the TNBS-induced rat model of colitis. The contractile responses to Ang II were evaluated in distinct regions of the colon of control animals or animals with colitis in the absence and presence of different antagonists/inhibitors. Endogenous levels of Ang II in the colon were assessed by ELISA and the number of AT1/AT2 receptors by qPCR. Ang II caused AT1 receptor-mediated colonic contraction that was markedly decreased along the colons of TNBS-induced rats, consistent with reduced AT1 mRNA expression. However, the effect mediated by Ang II is much more intricate, involving (in addition to smooth muscle cells and nerve terminals) ICC and EGC, which communicate by releasing ACh and NO in a complex mechanism that changes colitis, unveiling new therapeutic targets.
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Angiotensina II/genética , Colite/genética , Doenças Inflamatórias Intestinais/genética , Sistema Renina-Angiotensina/genética , Antagonistas de Receptores de Angiotensina/farmacologia , Animais , Colite/fisiopatologia , Colo/metabolismo , Colo/patologia , Sistema Nervoso Entérico/metabolismo , Sistema Nervoso Entérico/patologia , Humanos , Doenças Inflamatórias Intestinais/patologia , Células Intersticiais de Cajal/metabolismo , Células Intersticiais de Cajal/patologia , Masculino , Contração Muscular/genética , Contração Muscular/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Neuroglia/metabolismo , Neuroglia/patologia , Óxido Nítrico/metabolismo , Ratos , Receptor Tipo 1 de Angiotensina/genética , Receptor Tipo 2 de Angiotensina/genética , Transmissão Sináptica/genéticaRESUMO
BACKGROUND: Colonic transit disorder-induced constipation is a major complication in diabetic patients. PDGFRα+ (platelet-derived growth factor receptor α-positive) cells play critical roles in the inhibitory regulation of colonic motility, and FOXO3 (forkhead transcription factor 3) has a broad range of biological functions. The present study was designed to investigate the relationship between FOXO3 and PDGFRα+ cell proliferation in streptozotocin (STZ)-induced diabetic mice. METHODS: The major experimental techniques used in this paper are immunohistochemistry, quantitative RT-RCR and Western blotting for the evaluation of specific protein expression; ChIP assay for identifying the interaction between FOXO3 protein and the PDGFRα promotor; and lentiviral transfection for the overexpression of short hairpin RNAs (shRNAs) to down-regulate FOXO3. RESULTS: In proximal colonic smooth muscle tissue of STZ-induced diabetic mice, there was a significant increase in PDGFRα and Ki67 immunoreactivity. PDGFRα mRNA and protein expression levels were both significantly increased in colonic smooth muscle tissue, but PDGFRß expression was unchanged. Meanwhile, the expression of PDGF ligands, including both PDGFα and PDGFß, was significantly increased in diabetic colonic smooth muscle tissue. In whole cell and nuclear extracts, the expression of FOXO3 protein was also significantly increased; however, the expression of P-FOXO3 (phosphorylated FOXO3) protein was significantly decreased. When NIH cells were incubated with 50 mmol/L glucose for 12 h, 24 h and 48 h, the expression of PDGFRα significantly increased, and in whole cell and nuclear extracts, the expression of FOXO3 protein was significantly increased. However, the expression of P-FOXO3 protein was significantly decreased. FOXO3 could bind to a site on the PDGFRα promoter, and the basal expression of PDGFRα was significantly reduced when endogenous FOXO3 expression was knocked down with FOXO3 short hairpin RNA (shRNA) in NIH cells. The expression of phosphorylated Akt was significantly down-regulated in diabetic colonic muscle tissue. CONCLUSIONS: These results suggest that diabetes-induced colonic PDGFRα+ cell proliferation is mediated by FOXO3 up-regulation. FOXO3 up-regulation may be induced by inhibiting the PI3K/Akt signaling pathway in STZ-induced diabetic mice. PDGFRα+ cell proliferation could be a new target for clinical therapy of diabetes-induced colonic transit disorder.
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Colo/metabolismo , Diabetes Mellitus Experimental/patologia , Proteína Forkhead Box O3/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Animais , Glicemia/análise , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Proteína Forkhead Box O3/antagonistas & inibidores , Proteína Forkhead Box O3/genética , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Glucose/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Músculo Liso/metabolismo , Células NIH 3T3 , Fosfatidilinositol 3-Quinases/metabolismo , Regiões Promotoras Genéticas , Interferência de RNA , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estreptozocina , Regulação para Cima/efeitos dos fármacosRESUMO
BACKGROUND/AIMS: Excessive production of advanced glycation end products (AGEs) has been implicated in diabetes-related complications. This study aimed to investigate the mechanism by which AGEs potentially contribute to diabetes-associated colonic dysmotility. METHODS: Control and streptozotocin (STZ)-induced diabetic groups were treated with aminoguanidine (AG). The colonic transit time and contractility of circular muscle strips was measured. ELISA, immunohistochemistry and western blotting were used to measure Nε-carboxymethyl-lysine (CML) levels. Primary cultured colonic smooth muscle cells (SMCs) were used in complementary in vitro studies. RESULTS: Diabetic rats showed prolonged colonic transit time, weak contractility of colonic smooth muscle strips, and elevated levels of AGEs in the serum and colon tissues. cAMP levels, protein kinase-A (PKA) activities, and inositol 1,4,5-trisphosphate receptor type 3 (IP3R3) phosphorylation were increased in the colon muscle tissues of diabetic rats, whereas RhoA/Rho kinase activity and myosin phosphatase target subunit 1 (MYPT1) phosphorylation were reduced. The inhibition of the production of AGEs (AG treatment) reduced these effects. In cultured colonic SMCs, AGE-BSA treatment increased IP3R3 phosphorylation and reduced intracellular Ca2+ concentration, myosin light chain (MLC) phosphorylation, RhoA/Rho kinase activity, and MYPT1 phosphorylation. The PKA inhibitor H-89 and anti-RAGE antibody inhibited the AGE-BSA-induced impairment of Ca2+ signaling and cAMP/PKA activation. CONCLUSION: AGEs/RAGE participate in diabetes-associated colonic dysmotility by interfering with Ca2+ signaling in colonic SMCs through targeting IP3R3-mediated Ca2+ mobilization and RhoA/Rho kinase-mediated Ca2+ sensitization via the cAMP/PKA pathway.
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Cálcio/metabolismo , Colo/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Diabetes Mellitus Experimental/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Miócitos de Músculo Liso/metabolismo , Transdução de Sinais , Animais , Células Cultivadas , Colo/fisiopatologia , AMP Cíclico/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Trânsito Gastrointestinal , Masculino , Miócitos de Músculo Liso/patologia , Fosforilação , Ratos Sprague-Dawley , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismoRESUMO
PURPOSE: To report outcomes of children with constipation refractory to medical management and manometrically proven distal colonic dysmotility, managed with rectosigmoidectomy followed by Duhamel operation (Duhamel). METHODS: Children who underwent a Duhamel from 2009 onwards for intractable constipation and left colonic dysmotility were retrospectively reviewed. The primary end point was resolution of constipation, and secondary end point was postoperative complications. Continuous data were median (range). RESULTS: 11 patients (4 males) had Duhamel at 11 years (5-16) with constipation started from 2 years (1-8). Hirschsprung's disease was excluded. All Duhamels were performed with a covering ileostomy: 9 following a Hartmann procedure, one following a previously failed reversal of Hartmann, and one Duhamel performed with a pre-existing ileostomy. All ileostomies were subsequently closed. Median resection length was 22 cm (11-31). Length of stay was 8 days (5-23). Follow-up was 5 years (0.5-7). Age at final review was 15 years (10-18). Resolution of constipation occurred in nine patients (4 required antegrade continence enemas (ACE), 5 with laxative); two had persistent constipation and faecal incontinence despite ACE, ultimately requiring an ileostomy. Two postoperative small bowel obstructions required laparotomy. CONCLUSION: Duhamel performed in children with manometrically proven distal colonic dysmotility yielded 82% resolution of refractory constipation; half of them subsequently needed ACE.
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Colo/fisiopatologia , Doenças do Colo/complicações , Doenças do Colo/cirurgia , Constipação Intestinal/complicações , Constipação Intestinal/cirurgia , Complicações Pós-Operatórias/fisiopatologia , Adolescente , Criança , Pré-Escolar , Doenças do Colo/fisiopatologia , Constipação Intestinal/fisiopatologia , Feminino , Seguimentos , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Optimal surgical management of patients with intractable constipation and diffuse colonic motility is not well defined. We present a patient with such a history, who ultimately achieved successful surgical management of constipation through a stepwise approach. An 8-year-old female presents with longstanding constipation and diffuse colonic dysmotility demonstrated with colonic manometry. She initially underwent sigmoid resection and cecostomy which failed and required diverting ileostomy. We initially proceeded with an extended resection, colonic derotation (Deloyers procedure), and neo-appendicostomy (neo-Malone) which resulted in successful spontaneous stooling for 1 year. Her constipation recurred and she subsequently underwent completion colectomy with ileorectal anastomosis given that she previously demonstrated ability to stool independently. Six months from surgery the patient continues to stool daily with assistance of fiber and loperamide. This case highlights a stepwise surgical approach to managing constipation due to diffuse colonic dysmotility and demonstrates that diffuse dysmotility may benefit from an upfront subtotal resection; however, it is crucial to assess a patient's ability to empty their rectum prior.
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Ginger (Zingiber officinale) rhizomes are commonly used in foods and employed for many ailments including gastrointestinal disorders. Our main objective was to evaluate the effect of Zingiber officinale aqueous extract (ZOAE) on gastrointestinal (GI) physiological motility and colonic dysmotility. Thereby, Wistar rats were given loperamide (LP, 3 mg/kg, b.w.) and ZOAE (75, 150, and 300 mg/kg, b.w.) or yohimbine (YOH, 2 mg/kg, b.w.). ZOAE-action on intestinal secretion was assessed using Ussing chamber technique and intestinal motility with isometric transducer. GI-transit (GIT) and gastric emptying (GE) were evaluated with the charcoal meal test and the red phenol methods. ZOAE-bioactive components were analyzed by liquid chromatography-high resolution electrospray ionization mass spectrometry (LC-HRESIMS). Constipation was induced with LP and the different indicators such as stool composition, GIT, oxidative stress biological parameters, and colonic mucosa histological alteration were performed. Anti-constipation effect of ZOAE was confirmed on stool composition, GIT (53.42% to 85.57%), GE (55.47% to 98.88%), and re-established oxidative balance. ZOAE induces an amplitude increase of spontaneous intestinal contraction with EC50 of 10.52 µg/mL. No effect of ZOAE was observed on electrogenic transport of intestinal fluid. These findings suggest that ZOAE-bioactive candidates might exert an anti-constipation action and spontaneous intestinal contraction modulation.
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Background: To investigate the effect of the distribution and expression of interstitial cells of Cajal (ICCs) and platelet-derived growth factor receptor-α positive (PDGFRα+) cells in different colon segments on colonic motility in children with Hirschsprung disease (HSCR). Methods: Smooth muscles of the narrow and dilated segments of the colon were obtained from 16 pediatric patients with HSCR. The proximal margin was set as the control section. The mRNA and protein expressions of c-Kit, PDGFRα, ANO1, and SK3 channels were examined. Circular smooth muscle strips of the colon were prepared for performing electrophysiology experiments using electric field stimulation (EFS) and intervention from different drugs (TTX, NPPB, Apamin, L-NAME, and CyPPA). Results: The mRNA and protein expressions of c-Kit, ANO1, PDGFRα, and SK3 were much lower in the narrow segment than those in the dilated and proximal segments of the colon. The narrow segment showed a considerably spontaneous contraction of the muscle strip. After the EFS, the relaxation response decreased from the proximal to the narrow segment, whereas the contraction response increased. TTX blocking did not cause any significant changes in the narrow segment. In contrast, when NPPB, Apamin, L-NAME, and CyPPA were used to intervene in the muscle strips, the proximal segment showed a more sensitive inhibitory or excitatory response than the narrow segment. Conclusions: Downregulation of the ICCs and PDGFRα+ cells from the proximal to narrow segment may be responsible for the dysmotility of the colon in pediatric HSCR.
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Palmitoylethanolamide (PEA), an endogenous lipid mediator, is emerging as a promising pharmacological agent in multiple neurodegenerative disorders for its anti-inflammatory and neuroprotective properties. However, its effects on enteric inflammation and colonic dysmotility associated with Alzheimer's disease (AD) are lacking. This study was designed to investigate the beneficial effect of PEA administration in counteracting the enteric inflammation and relieving the bowel motor dysfunctions in an AD mouse model, SAMP8 mice. In addition, the ability of PEA in modulating the activation of enteric glial cells (EGCs), pivotally involved in the pathophysiology of bowel dysfunctions associated with inflammatory conditions, has also been examined. SAMP8 mice at 4 months of age were treated orally with PEA (5 mg/kg/day) for 2 months. SAMR1 animals were employed as controls. At the end of treatment, parameters dealing with colonic motility, inflammation, barrier integrity and AD protein accumulation were evaluated. The effect of PEA on EGCs was tested in cultured cells treated with lipopolysaccharide (LPS) plus ß-amyloid 1-42 (Aß). SAMP8 treated with PEA displayed: 1) an improvement of in vitro colonic motor activity, citrate synthase activity and intestinal epithelial barrier integrity and 2) a decrease in colonic Aß and α-synuclein (α-syn) accumulation, S100-ß expression as well as enteric IL-1ß and circulating LPS levels, as compared with untreated SAMP8 mice. In EGCs, treatment with PEA counteracted the increment of S100-ß, TLR-4, NF-κB p65 and IL-1ß release induced by LPS and Aß. These results suggest that PEA, under a condition of cognitive decline, prevents the enteric glial hyperactivation, reduces AD protein accumulation and counteracts the onset and progression of colonic inflammatory condition, as well as relieves intestinal motor dysfunctions and improves the intestinal epithelial barrier integrity. Therefore, PEA represents a viable approach for the management of the enteric inflammation and motor contractile abnormalities associated with AD.
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BACKGROUND: 'Intractable constipation' (IC) is constipation unresponsive to 3â¯months of optimal conventional treatment. Colonic manometry (CM) is recommended as a diagnostic modality for evaluation of these children. This study aimed to review outcomes of children with IC who were managed surgically at a single tertiary care center. METHODS: Records of children with IC who were treated with ACE (antegrade colonic enema), colostomy, or ileostomy (2006-2018) were reviewed. "Success" was defined as adequate evacuation without need for further unplanned surgery. Data are median (range). RESULTS: Sixty-seven children underwent surgery, of whom 56 with preoperative CM were included. Age at surgery was 8.6 (3.3-15.1) years. Eight had normal manometry and underwent ACE with 75% success. Thirty-six had left-sided dysfunction and underwent ACE (18), colostomy (14) or ileostomy (4) as initial intervention with 61, 70, and 100% success. Twelve with pancolonic dysfunction underwent ACE (6) or ileostomy (6) with 60 and 100% success. Twenty underwent repeat manometry 2.2â¯years (10â¯months-7.6â¯years) after surgery. Of 18 with stoma, 8 had resolution or improvement and of these, 7 underwent stoma reversal with a simultaneous ACE. Two patients with ACE had improvement, 1 is still on ACE washouts, and 1 is off all treatment. Ten with persistent dysfunction remain diverted. At 3.2â¯years (4â¯months-9.9â¯years) follow-up, 18 remain on ACE washouts, 9 have colostomy, 19 ileostomy, and 10 are off treatment and doing well. CONCLUSION: We present a large series of patients who were surgically managed for IC. CM may guide therapy in these children. TYPE OF STUDY: Retrospective comparative study LEVEL OF EVIDENCE: Level III.
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Colo/cirurgia , Constipação Intestinal/cirurgia , Manometria , Adolescente , Criança , Pré-Escolar , Colo/fisiopatologia , Colostomia , Constipação Intestinal/fisiopatologia , Enema , Feminino , Humanos , Ileostomia , Masculino , Estudos Retrospectivos , Estomas CirúrgicosRESUMO
We present a case of a 14-year-old boy with chronic distension, poor growth, and chronic constipation. He undergoes anorectal manometry and rectal biopsy, confirming the diagnosis of Hirschsprung disease (HD). The case is presented with a key image and associated questions to prompt discussion on strategies for management and treatment of HD in late-diagnosed children.
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Colonic dysmotility as a complication of diabetes affects public health; however, the underlying molecular mechanisms have remained elusive. Insulin-like growth factor-1 (IGF-1) was previously demonstrated to prevent apoptosis of colonic smooth muscle cells (SMCs) and alleviate colonic dysmotility in diabetic rats. However, the regulatory mechanisms upstream of IGF-1 in colonic dysmotility have remained to be determined. The present study reports on microRNA-155 (miR-155), initially identified using bioinformatics, as a direct upstream regulator of IGF-1. In colonic SMCs, miR-155 negatively regulated IGF-1 expression at the post-transcriptional level, as identified through ectopic overexpression and knockdown experiments. A luciferase reporter assay further demonstrated that miR-155 inhibits IGF-1 through binding to its 3'-untranslated region. Furthermore, overexpression of miR-155 led to increased apoptosis of colonic SMCs and a decrease in the thickness of colonic smooth muscle tissues of diabetic mice, indicating miR-155 aggravates colonic dysmotility. By contrast, knockdown of miR-155 induced the opposite effect. Overall, the results of the present study suggest a role of miR-155 in colonic dysmotility, thereby providing a novel therapeutic target.
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The detailed process and mechanism of colonic motility are still unclear, and colonic motility disorders are associated with numerous clinical diseases. Colonic manometry is considered to the most direct means of evaluating colonic peristalsis. Colonic manometry has been studied for more than 30 years; however, the long duration of the examination, high risk of catheterization, huge amount of real-time data, strict catheter sterilization, and high cost of disposable equipment restrict its wide application in clinical practice. Recently, high-resolution colonic manometry (HRCM) has rapidly developed into a major technique for obtaining more effective information involved in the physiology and/or pathophysiology of colonic contractile activity in colonic dysmotility patients. This review focuses on colonic motility, manometry, operation, and motor patterns, and the clinical application of HRCM. Furthermore, the limitations, future directions, and potential usefulness of HRCM in the evaluation of clinical treatment effects are also discussed.
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BACKGROUND: The mechanism underlying gastrointestinal (GI) dysmotility associated with chronic pancreatitis (CP) has not been fully elucidated, and enteric nervous system (ENS) has an important regulatory role in gastrointestinal motor function. The aim of this study is to investigate the effect of ENS in the colonic hypomotility induced by trinitrobenzene sulfonic acid (TNBS) infusion which mimics CP. METHODS: Male Sprague-Dawley rats were submitted to CP which was induced by pancreatic infusion of 2% TNBS, or sham group with treatment of equal saline. Three weeks after induction of CP, we pathologically examined the inflammation of pancreas and counted the number of withdrawal events stimulated by Von Frey filaments to evaluate hyperalgesia. The gastrointestinal transit rate was measured using Carbon inkl driving test, and the contraction activities of colonic muscle strip were studied in an organ bath system. The expression of choline acetyltransferase (ChAT) and nitric oxide synthase (NOS) in colonic myenteric plexus (MP) of ENS were investigated by Western blotting and double immunofluorescence staining. KEY RESULTS: In TNBS-treated group, rats had the signs of chronic pancreatitis 3 weeks after intraductal infusion and had increased sensitivity to mechanical stimulation of the abdomen. For rats with CP, the gastrointestinal transit rate was reduced; in addition, the contractile activities of longitudinal muscle (LM) and circular muscle (CM) strips of distal colon in TNBS group were lower than those in sham group. Immunofluorescence demonstrated that the percentage of ChAT-immunoreactive (IR) neurons in the MP was decreased, but the proportion of NOS-IR neurons in the MP was increased when compared with sham-operated group. Western blotting proved that TNBS infusion down-regulated ChAT but up-regulated NOS expression in the colon MP. CONCLUSIONS & INFERENCES: Decreased ChAT-IR neurons and increased NOS-IR in the MP of colon ENS may contribute to the pathogenesis of colonic dysmotility in CP.
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Colo/fisiopatologia , Motilidade Gastrointestinal/fisiologia , Plexo Mientérico/fisiopatologia , Neurônios/fisiologia , Pancreatite Crônica/fisiopatologia , Animais , Colo/patologia , Sistema Nervoso Entérico/patologia , Sistema Nervoso Entérico/fisiopatologia , Masculino , Plexo Mientérico/patologia , Neurônios/patologia , Técnicas de Cultura de Órgãos , Pancreatite Crônica/patologia , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND/AIMS: Abnormal visceral sensitivity and disordered motility are common in patients with diabetes mellitus. The purpose of the present study was to investigate whether visceral sensation and bowel motility were altered in a rat model of type 2 diabetes mellitus accompanied by weight loss. METHODS: A type 2 diabetic rat model in adulthood was developed by administrating streptozotocin (STZ; 90 mg/kg, i.p.) to neonatal rats. Eight weeks after STZ administration, rats with blood glucose level of 200 mg/dL or higher were selected and used as diabetic group (n = 35) in this study. Abdominal withdrawal reflex and arterial pulse rate were measured to examine visceral nociception induced by colorectal distension (0.1-1.0 mL). The amplitude, frequency, and area under the curve (AUC) of spontaneous phasic contractions of colonic circular muscles were recorded in vitro to examine colonic motility. RESULTS: STZ-treated diabetic rats gained significantly less weight for 8 weeks than control (P < 0.01). Forty-eight percent of the diabetic rats showed enhanced visceral nociceptive response to colorectal distension. Diabetic rats did not differ from control rats in colorectal compliance. However, the frequency and AUC, not the amplitude, of colonic spontaneous contraction in vitro was significantly decreased in diabetic rats compared to control rats (P < 0.01 in frequency and P < 0.05 in AUC). CONCLUSIONS: These results demonstrate visceral hypersensitivity and colonic dysmotility in a rat model of type 2 diabetes mellitus accompanied by weight loss.
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Cellular apoptosis and colonic dysmotility are involved in diabetes mellitus (DM) complications. Insulin-like growth factor-1 (IGF-1) is known to affect apoptosis and proliferation. Here, we demonstrated that the treatment of 1500 ng/kg IGF-1 partly recovers the decrease of the muscle thickness, body weight and gastrointestinal transit rate in DM rats. The gastrointestinal transit rate is positively correlated with the IGF-I level, but negatively correlated with the level of colonic cellular apoptosis. The DM-induced colonic apoptosis is also attenuated by the IGF-1 stimulation. Moreover, IGF-1 inhibits the apoptosis of the isolated colonic SMCs in vitro via the activation of PI3K/Akt and ERK1/2 signaling pathways. Taken together, our data indicated that IGF-1 inhibits the DM-induced colonic SMC apoptosis and might be involved in the alleviation of colonic dysmotility in diabetic rats.