Sm. Ward et al., IMPAIRED DEVELOPMENT OF INTERSTITIAL-CELLS AND INTESTINAL ELECTRICAL RHYTHMICITY IN STEEL MUTANTS, American journal of physiology. Cell physiology, 38(6), 1995, pp. 1577-1585
Electrical rhythmicity in the gastrointestinal tract may originate in
interstitial cells of Cajal (IC). Development of IC in the small intes
tine is linked to signaling via the tyrosine kinase receptor, c-Kit. I
C express c-kit protein, and disruption of c-Kit signaling causes brea
kdown in IC networks and loss of slow waves. We tested whether mutatio
ns 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/Sl(d)) at 5-10 days postpartum
, but these cells formed an abnormal network. IC-MY were not observed
in adult Sl/Sl(d) animals. IC in the deep muscular plexus (IC-DMP) app
eared normal in Sl/Sl(d) animals. Electrical slow waves, normally pres
ent in the small intestine, were absent in Sl/Sl(d) animals (10-30 day
s postpartum). Neural inputs were intact in Sl/Sl(d) animals. Steel fa
ctor appears important for the development of certain classes of IC, a
nd IC-MY appear to be involved in the generation of electrical rhythmi
city in the small intestine.