vasoactive-intestinal-peptide and Colonic-Diseases

Topics: Bile Acids and Salts; Colonic Diseases; Diarrhea, Infantile; Exocrine Pancreatic Insufficiency; Gastrointestinal Neoplasms; Humans; Infant; Infant, Newborn; Intestinal Absorption; Intestinal Diseases; Intestinal Mucosa; Intestinal Secretions; Intestine, Small; Intestines; Protein-Energy Malnutrition; Rotavirus Infections; Vasoactive Intestinal Peptide

Topics: alpha 1-Antitrypsin; Bacterial Toxins; Cholestyramine Resin; Colonic Diseases; Deoxycholic Acid; Diarrhea; Humans; Immunoglobulin G; Iodine Radioisotopes; Malabsorption Syndromes; Prostaglandins; Protein-Losing Enteropathies; Serum Albumin; Vasoactive Intestinal Peptide; Water-Electrolyte Imbalance

Previous studies showed increased plasma motilin and substance P concentrations and accelerated motor function in the small bowel and colon in patients with carcinoid diarrhea. Octreotide is beneficial in patients with carcinoid syndrome. Our hypothesis was that octreotide inhibits accelerated motility and gut neuropeptides in carcinoid syndrome.. In 12 patients with metastatic carcinoid syndrome, we investigated the effect of octreotide 50 microg s.c. t.i.d (n = 6) or placebo (n = 6) on postprandial symptoms, GI transit, colonic motility, and circulating levels of selected circulating peptides and amines.. Octreotide reduced postprandial flushing (p = 0.03) but not pain. Octreotide significantly retarded overall colonic transit and proximal colonic emptying (p < 0.05); it tended to prolong small bowel transit time (p = 0.13) and to reduce postprandial colonic tone (p = 0.08) compared with placebo. Octreotide also reduced circulating levels of peptide YY, neurotensin, vasoactive intestinal polypeptide, and substance P but had no effect on plasma motilin, neuropeptide Y, calcitonin gene-related peptide, or histamine after meal ingestion.. Octreotide ameliorates gut motor dysfunctions that characterize carcinoid diarrhea; the potential role of specific antagonism of serotonin, substance P, and vasoactive intestinal polypeptide alone or in combination with agents that inhibit their release in carcinoid diarrhea deserves further study.

Topics: Aged; Antineoplastic Agents, Hormonal; Calcitonin Gene-Related Peptide; Colon; Colonic Diseases; Diarrhea; Digestion; Double-Blind Method; Female; Flushing; Gastrointestinal Agents; Gastrointestinal Motility; Gastrointestinal Transit; Histamine; Humans; Intestine, Small; Male; Malignant Carcinoid Syndrome; Middle Aged; Motilin; Neuropeptide Y; Neuropeptides; Neurotensin; Octreotide; Peptide YY; Placebos; Serotonin Antagonists; Substance P; Vasoactive Intestinal Peptide

Shigella, an enteroinvasive bacteria induces a major inflammatory response responsible for acute rectocolitis in humans. However, early effect of Shigella flexneri (S. flexneri) infection upon the human mucosa and its microenvironement, in particular the enteric nervous system, remains currently unknown. Therefore, in this study, we sought to characterize ex vivo the early events of shigellosis in a model of human colonic explants. In particular, we aimed at identifying factors produced by S. flexneri and responsible for the lesions of the barrier. We also aimed at determining the putative lesions of the enteric nervous system induced by S. flexneri.. We first showed that, following 3 h of infection, the invasive but not the non-invasive strain of S. flexneri induced significant desquamation of the intestinal epithelial barrier and a reduction of epithelial height. These changes were significantly reduced following infection with SepA deficient S. flexneri strains. Secondly, S. flexneri induced rapid neuronal morphological alterations suggestive of cell death in enteric submucosal neurones. These alterations were associated with a significant increase in the proportion of vasoactive intestinal peptide (VIP) immunoreactive (IR) neurons but not in total VIP levels. The NMDA receptor antagonist MK-801 blocked neuronal morphological changes induced by S. flexneri, but not the increase in the proportion of VIP-IR.. This human explant model can be used to gain better insight into the early pathogenic events following S. flexneri infection and the mechanisms involved.

Topics: Adult; Aged; Aged, 80 and over; Colonic Diseases; Dysentery, Bacillary; Enteric Nervous System; Epithelium; Humans; Intestinal Mucosa; Middle Aged; Neurons; Shigella flexneri; Vasoactive Intestinal Peptide; Young Adult

Intestinal inflammation causes hyporesponsiveness of the inflamed tissue to secretagogues but little is known about the behaviour of the areas proximal to the site of inflammation. We studied the responses of the proximal segment of the colon to carbachol, histamine, isobutylmethylxanthine (IBMX) and vasoactive intestinal peptide (VIP) in rats with trinitrobenzenesulphonic acid (TNBS)-induced, chronic inflammation of the distal colon. Macroscopic and biochemical analysis ruled out the presence of inflammation in the proximal colon. When mounted in Ussing chambers under voltage-clamp conditions, basal transport and conductance were not affected. However, the maximum response in the concentration/response curves (short-circuit current) for carbachol and histamine was reduced in TNBS-treated rats, without changes in the EC(50). This effect corresponded to reduced chloride secretion, as demonstrated by ion substitution experiments. The responses to IBMX and VIP were virtually unaffected. The inhibitory effect was abolished by pretreatment with the neural blockers tetrodotoxin and lidocaine but not indomethacin, suggesting that the enteric nervous system is responsible for the inhibition. In conclusion, chronic distal inflammation of the distal colon results in inhibition of calcium-dependent secretion in the proximal colon via a reduction of the contribution of the enteric nervous system.

Topics: 1-Methyl-3-isobutylxanthine; Animals; Carbachol; Cholinergic Agonists; Colon; Colonic Diseases; Female; Glutathione; Histamine; Inflammation; Patch-Clamp Techniques; Peroxidase; Phosphodiesterase Inhibitors; Rats; Rats, Wistar; Vasoactive Intestinal Peptide

The neuropeptides substance P, vasoactive intestinal polypeptide, and the recently discovered peptide secretoneurin are neurotransmitters of the intrinsic nervous system of the gut and effect gut motility. The aim of this study was to investigate whether these neuropeptides are involved in the pathophysiology of large bowel ileus. Five patients underwent colonic resections for obstructive cancer of the colon. Full-thickness specimens of the resected colon were taken 10 cm proximal and 10 cm distal to the site of tumor obstruction. Substance P-, vasoactive intestinal polypeptide-, and secretoneurin-like immunoreactivities were measured in the specimens by radioimmunoassay. In addition immunocytochemistry was performed. Tissue levels of substance P, vasoactive intestinal polypeptide, and secretoneurin were lower in the prestenotic than in the poststenotic bowel segment. In accordance, immunocytochemistry revealed a denser staining of ganglion cells and fibers for all three neuropeptides in the poststenotic bowel. The decreased tissue levels of substance P, vasoactive intestinal polypeptide, and secretoneurin in the prestenotic bowel segment may contribute to the final decompensation of obstructive ileus.

Topics: Aged; Colon; Colonic Diseases; Colonic Neoplasms; Enteric Nervous System; Female; Humans; Intestinal Obstruction; Neuropeptides; Secretogranin II; Substance P; Vasoactive Intestinal Peptide

Colonic strictures are rare in patients who have cystic fibrosis, but recently have developed in those who have been treated with delayed-release high-dose pancreatic enzyme supplements. Colonic strictures from eight such pediatric patients showed neural abnormalities consisting of ganglion cell hyperplasia and ectopia, and intermyenteric plexus hyperplasia. Cholinergic and adrenergic stains of mucosal nerve fibers were more prominent in histological sections of the cystic fibrosis strictures than in sections from colons of children without cystic fibrosis. The mean grade of staining with acetylcholinesterase in the lamina propria of the strictured cystic fibrosis colons was 2.38 +/- 1.25, compared with .93 +/- .93 (P < .055) in bowels from children without cystic fibrosis. The mean grade for tyrosine hydroxylase staining in the lamina propria was 2 +/- .97 in the strictures and was .79 +/- .81 (P < .05) in the bowels of children who did not have cystic fibrosis. Vasoactive intestinal peptide staining in bowels from children with cystic fibrosis with and without stricture did not differ significantly from that of children without cystic fibrosis. Vasculopathy consisting of fibrointimal hyperplasia in submucosal veins and mesenteric arteries was found only in colonic strictures owing to cystic fibrosis. Colonic strictures in patients with cystic fibrosis who received high-dose pancreatic enzyme supplements contain ganglion cell abnormalities, and mucosal cholinergic and adrenergic activity may be increased in these strictures. The stricture vasculopathy may be drug-related and/or related to increased catecholamine activity.

Topics: Acetylcholinesterase; Adolescent; Adrenergic Fibers; Catecholamines; Child; Child, Preschool; Cholinergic Fibers; Choristoma; Colon; Colonic Diseases; Constriction, Pathologic; Cystic Fibrosis; Female; Ganglia; Humans; Hyperplasia; Infant, Newborn; Intestinal Mucosa; Male; Mesenteric Arteries; Pancreas; Pancreatic Extracts; Peripheral Nervous System Diseases; Tunica Intima; Tyrosine 3-Monooxygenase; Vascular Diseases; Vasoactive Intestinal Peptide