Impaired development of interstitial cells and intestinal
electrical rhythmicity in steel mutants.
Ward, Sean M., Alan J. Burns, Shigeko Torihashi, Sarah C. Harney, and
Kenton M. Sanders.
Department of Physiology, University of Nevada School of Medicine,
Reno, NV 89557 USA, (702) 784-6908 or FAX (702) 784-6903, e-mail:
kent@physio.unr.edu, Department of Anatomy, Nagoya University School
of Medicine, Tsurumai-cho 65, Nagoya 466, Japan, (FAX 052-741
-2196)
APStracts 2:0336C, 1995.
Electrical rhythmicity in the gastrointestinal tract may originate in
interstitial cells of Cajal (ICs). Development of ICs in the small
intestine is linked to signalling via the tyrosine kinase receptor,
c-kit. ICs express c-kit protein and disruption of c-kit signalling
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. ICs were found in the region of the
myenteric plexus (IC-MY) in mice with steel mutations (i.e. Sl/Sld)
at 5-10 day post partum (pp), but these cells formed an abnormal
network. IC-MY were not observed in adult Sl/Sld animals. ICs 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 pp). Neural inputs were intact
in Sl/Sld animals. Steel factor appears important for the development
of certain classes of ICs, and IC-MY appear to be involved in the
generation of electrical rhythmicity in the small intestine.
Received 17 May 1995; accepted in final form 6 September 1995.
APS Manuscript Number C283-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 September 1995.