Calcitonin Gene-related Peptide Immunoreactivity in the Muscle Layer of Small Intestine; Its Action on Interstitial Cell / 체질인류학회지

In addition to the central and the peripheral nervous system, calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) has been identified throughout the enteric nervous system. Several functions of the CGRP in gastrointestinal (G-I) tract has been identified, but the effect of CGRP on G-I motility is unclear. The distribution of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) in the murine small bowel were studied by using immunohistochemistry, also analyzed functionally by using electrophysiological method. Immunohistochemical studies demonstrated that CGRP-LI is localized in both nerve fibers and myenteric ganglion cells in the whole-mount preparation of murine small intestine. Double labelling with CGRP and c-kit investigated by confocal microscope was shown that CGRP-LI enteric nerve fiber surrounded the c-kit positive interstitial cells of Cajal (ICC). Electrophysiological finding revealed that treatment of CGRP inhibited electrical activity on culture ICC. Our results suggest a CGRP innervation of murine small bowel ICC. The released CGRP from enteric nerve terminals may induce relaxation of small bowel through the inhibition of ICC.

Change of Interstitial Cells of Cajal (ICC) and Intestinal Motility in Murine Small Bowel Obstruction / 대한해부학회지

Interstitial cells of Cajal (ICC) are the pacemakers in gastrointestinal slow wave, and also transduce signal inputs from the enteric nervous system to smooth muscle. The abnormal motility corresponded to a lack or decreasing of ICC and a disruption of electrical slow waves. So we developed partial obstruction model in murine small intestine and investigated changes in the ICC networks and electrical activity in the obstructed bowel using c-kit immunohistochemistry and intracelluar electrophysiological techniques. Two weeks following the onset of a partial obstruction, the small intestine increased in diameter and muscular hypertrophy was developed oral to the obstruction site. ICC were absent or only weak at 1 ~25 mm oral to the occlusion site, and this disruption was accompanied by the loss of electrical slow wave. ICC networks and slow waves were normal appearance aboral to the clip. In conclusion, The present results showed that partial intestinal obstruction induced the loss of ICC networks and slow waves. These result will provide a valuable aid for understanding pathogenesis of intestinal motility disorder, and this model may be an important tool for evaluating genetic or molecular factor for the therapeutic opportunities of motility disorder in human.