title: Gastric enteric neurones that respond to luminal injury.
abstract: Challenge of the rat gastric mucosa with HCl stimulates intrinsic neurones in the myenteric plexus of the stomach as demonstrated by immunohistochemical detection of c-Fos. In multiple labelling experiments of whole-mounts and sections of the gastric corpus we determined the chemical code of the stimulated neurones and investigated further whether neural pathways involving capsaicin-sensitive afferents, cholinergic neurones or the vagal system contribute to the stimulation of these neurones. Intragastric (IG) administration of 0.5 m HCl caused c-Fos expression in 12% of myenteric neurones, whereas IG saline failed to induce c-Fos. All stimulated neurones stained for nitric oxide synthase (NOS), vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY), but not for choline acetyltransferase (ChAT). Fibres coexpressing NOS/VIP/NPY were found predominantly in the external muscle layer and the muscularis mucosae of the stomach wall. Pretreatment with capsaicin or hexamethonium, combination of both pretreatments or vagotomy reduced HCl-induced c-Fos expression by 54%, 66%, 63% and 68%, respectively. The data indicate that mucosal acid challenge of the stomach stimulates inhibitory motor neurones in the myenteric plexus and that capsaicin-sensitive afferents as well as cholinergic neurones participate in the neuronal stimulation probably via a vago-vagal reflex.
authors.affiliation: Department of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria. rudolf.schicho@uni-graz.at
authors.forename: R
authors.initials: R
authors.lastname: Schicho
authors.forename: P
authors.initials: P
authors.lastname: Holzer
authors.forename: I Th
authors.initials: IT
authors.lastname: Lippe
mesh_terms: D000818:Animals; D017615:Enteric Nervous System / Q000166:cytology / Q000502:physiology*; D005753:Gastric Mucosa / Q000187:drug effects / Q000293:injuries; D016762:Genes, fos / Q000187:drug effects*; D006851:Hydrochloric Acid / Q000633:toxicity; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D013270:Stomach / Q000293:injuries / Q000294:innervation*
chemical_list: D006851:Hydrochloric Acid