neuropeptide-y and Ileitis

Properties of enteric neurons are transformed by inflammation and protein kinase C (PKC) isoforms are involved both in long-term changes in enteric neurons, and in transducing the effects of substances released during inflammation. We investigated roles of PKCepsilon in submucosal neurons by studying translocation in response to inflammatory mediators, effects on neuron excitability, and the changes in PKCepsilon distribution in a trinitrobenzene sulphonate model of ileitis.. Immunohistochemical detection and analysis of association with membrane and cytosolic fractions, and Western blot analysis of cytosolic and particulate fractions were used to quantify translocation. Electrophysiology methods were used to measure effects on neuron excitability.. All submucosal neurons were immunoreactive for the novel PKC, PKCepsilon, and direct PKC activators, phorbol 12,13-dibutyrate, ingenol 3,20-dibenzoate, and the PKCepsilon-specific activator, transactivator of transduction-Psiepsilon receptor for activated C kinase, all caused PKCepsilon translocation from cytoplasm to surfaces of the neurons. Electrophysiologic studies showed that the stimulant of novel PKCs, ingenol (1 micromol/L), increased excitability of all neurons. Stimulation of protease-activated receptors caused PKCepsilon translocation selectively in vasoactive intestinal peptide secretomotor neurons, whereas a neurokinin 3 tachykinin receptor agonist caused translocation in neuropeptide Y and calretinin neurons. In all cases translocation was reduced significantly by a PKCepsilon-specific translocation inhibitor peptide. Increased PKCepsilon at the plasma membrane occurred in all neurons 6-7 days after an inflammatory stimulus.. Major targets for PKCepsilon include ion channels near the plasma membrane. PKCepsilon is likely to have a significant role in controlling the excitability of submucosal neurons and is probably an intermediate in causing hyperexcitability after inflammation.

Topics: Action Potentials; Animals; Blotting, Western; Calbindin 2; Cell Membrane; Cytoplasm; Disease Models, Animal; Diterpenes; Dose-Response Relationship, Drug; Enzyme Activation; Enzyme Activators; Guinea Pigs; Ileitis; Ileum; In Vitro Techniques; Inflammation Mediators; Kinetics; Neuropeptide Y; Oligopeptides; Peptide Fragments; Phorbol 12,13-Dibutyrate; Protein Kinase C-epsilon; Protein Transport; Receptor, PAR-2; Receptors, Neurokinin-3; S100 Calcium Binding Protein G; Signal Transduction; Submucous Plexus; Substance P; Trinitrobenzenesulfonic Acid; Trypsin; Vasoactive Intestinal Peptide

In the present study the ELISA test was used to investigate the influence of chemically-induced ileitis on the dorsal root ganglia (DRG) neurons in the pig. The preliminary retrograde fluorescent tracing study revealed that ileum-projecting sensory neurones (IPN) are located in the thoracic ganglia (Th; Th8-Th13). The ileum wall in experimental (E) pigs was subjected to multiple injection with 4% paraformaldehyde to induce inflammation, while in the control (C) animals the organ was injected with 0.1 M phosphate buffer. Three days later the DRGs (Th8-Th13) collected from all the animals were evaluated for VIP, SP, CGRP, NPY, GAL and SOM content with an ELISA test. It was found that the inflammation increased clearly the tissue level of SP, GAL and SOM.

Topics: Animals; Calcitonin Gene-Related Peptide; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Dyes; Formaldehyde; Galanin; Ganglia, Spinal; Ileitis; Ileum; Neurons, Afferent; Neuropeptide Y; Neuropeptides; Polymers; Somatostatin; Substance P; Sus scrofa; Thoracic Vertebrae; Up-Regulation; Vasoactive Intestinal Peptide; Visceral Afferents

There have been conflicting results regarding the effect of Crohn's disease on the neurochemical composition of the enteric nervous system.. To examine the effect of Crohn's disease on the neurochemical composition of enteric nerve fibres and cell bodies using whole mount preparations of human ileum.. Whole wall ileum from seven normal subjects and nine patients with Crohn's disease was used to investigate the neurochemical composition of neurones and nerve fibres in the myenteric plexus, circular muscle, and serosa layer of ileum using immunohistochemical techniques.. Increased tyrosine hydroxylase, 5-hydroxytryptamine, and neuropeptide Y immunoreactivity was exclusively seen in the myenteric plexus. There was increased neurofilament immunoreactivity in the myenteric plexus and nerve fibres of the circular muscle layer, and thick bundles of immunoreactive nerve fibres in the serosa layer. Increased vasoactive intestinal polypeptide, nitric oxide synthase, and pituitary adenylate cyclase activating peptide immunoreactivity was seen in the myenteric plexus and nerve fibres of the circular muscle layer, and aggregates of inflammatory cells in the serosa layer of the afflicted segment of Crohn's ileum. In addition, there was a chaotic display of nerve fibres containing some of the neuroactive substances with a high frequency of enlarged varicosities in the myenteric ganglia and/or nerve fibres of the circular muscle layer of Crohn's ileum.. Results show quantitative as well as qualitative changes in the neurochemical composition of enteric nerve fibres and nerve cell bodies of Crohn's ileum. These changes and the presence of nitric oxide synthase and peptides immunoreactive inflammatory cells in the serosa layer suggest that nerve-immune interactions may have a significant role in the process of the inflammatory changes seen in Crohn's ileitis.

Topics: Adult; Aged; Crohn Disease; Enteric Nervous System; Fluorescent Antibody Technique, Indirect; Humans; Ileitis; Ileum; Image Processing, Computer-Assisted; Middle Aged; Neuropeptide Y; Neuropeptides; Neurotransmitter Agents; Nitric Oxide Synthase; Pituitary Adenylate Cyclase-Activating Polypeptide; Serotonin; Tyrosine 3-Monooxygenase; Vasoactive Intestinal Peptide