title: Impaired development of interstitial cells and intestinal electrical rhythmicity in steel mutants.
abstract: Electrical rhythmicity in the gastrointestinal tract may originate in interstitial cells of Cajal (IC). Development of IC in the small intestine is linked to signaling via the tyrosine kinase receptor, c-kit. IC express c-kit protein, and disruption of c-kit signaling causes breakdown in IC networks and loss of slow waves. We tested whether mutations in steel factor, the ligand for c-kit, affect the development of IC networks. IC were found in the region of the myenteric plexus (IC-MY) in mice with steel mutations (i.e., Sl/Sld) at 5-10 days postpartum, but these cells formed an abnormal network. IC-MY were not observed in adult Sl/Sld animals. IC in the deep muscular plexus (IC-DMP) appeared normal in Sl/Sld animals. Electrical slow waves, normally present in the small intestine, were absent in Sl/Sld animals (10-30 days postpartum). Neural inputs were intact in Sl/Sld animals. Steel factor appears important for the development of certain classes of IC, and IC-MY appear to be involved in the generation of electrical rhythmicity in the small intestine.
authors.affiliation: Department of Physiology, University of Nevada School of Medicine, Reno 89557, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Ward
authors.forename: A J
authors.initials: AJ
authors.lastname: Burns
authors.forename: S
authors.initials: S
authors.lastname: Torihashi
authors.forename: S C
authors.initials: SC
authors.lastname: Harney
authors.forename: K M
authors.initials: KM
authors.lastname: Sanders
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002874:Chromosome Mapping; D007421:Intestine, Small / Q000166:cytology* / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D008854:Microscopy, Electron; D009154:Mutation; D009197:Myenteric Plexus / Q000378:metabolism; D016065:Myoelectric Complex, Migrating; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D015398:Signal Transduction; D019089:Stem Cell Factor / Q000235:genetics*
chemical_list: D019089:Stem Cell Factor; D019009:Proto-Oncogene Proteins c-kit