title: Interstitial cells of Cajal and neuromuscular transmission in the rat lower oesophageal sphincter.
abstract: The distribution of interstitial cells of Cajal (ICC) and neurotransmission were investigated in lower oesophageal sphincter (LES) circular muscle strips from Sprague-Dawley (SD) rats, Ws/Ws mutant rats and their wild-type (+/+) siblings. Intramuscular c-Kit-positive cells, confirmed to be ICC-IM by electron microscopy, were observed throughout both muscle layers from SD and +/+ rats. In contrast, c-Kit-positive, ultrastructurally typical ICC-IM were absent in Ws/Ws. LES strips from Ws/Ws rats showed increased spontaneous contractile activity. Strips from SD and +/+ rats, responded to electrical neuronal stimulation with a relaxation that was in part L-NNA and in part apamin sensitive, followed by a contraction which was decreased by atropine. In Ws/Ws rats, similar to +/+ rats, neurally mediated relaxation was L-NNA and apamin sensitive and the contraction was decreased by atropine. We conclude that in the rat LES, relaxation is mediated by NO and an apamin-sensitive mediator, and contraction primarily by acetylcholine. Despite the absence of c-Kit-positive ICC, nerve-muscle interaction can be accomplished likely by diffusion of neurotransmitters to the smooth muscle cells. The lack of c-Kit-positive ICC is related to an increase in the basal tone and spontaneous contractile activity. The presence of fibroblast-like ICC in Ws/Ws rats might represent immature ICC whose possible functions need further investigation.
authors.affiliation: Fundació de Gastroenterologia Dr Francisco Vilardell, Barcelona, Catalunya, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Farré
authors.forename: X-Y
authors.initials: XY
authors.lastname: Wang
authors.forename: E
authors.initials: E
authors.lastname: Vidal
authors.forename: A
authors.initials: A
authors.lastname: Domènech
authors.forename: M
authors.initials: M
authors.lastname: Pumarola
authors.forename: P
authors.initials: P
authors.lastname: Clave
authors.forename: J D
authors.initials: JD
authors.lastname: Huizinga
authors.forename: M
authors.initials: M
authors.lastname: Jiménez
mesh_terms: D000818:Animals; D049630:Esophageal Sphincter, Lower / Q000294:innervation* / Q000378:metabolism*; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D009119:Muscle Contraction / Q000502:physiology; D009126:Muscle Relaxation / Q000502:physiology; D009130:Muscle, Smooth / Q000294:innervation* / Q000378:metabolism*; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D019089:Stem Cell Factor / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D019089:Stem Cell Factor