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

ABSTRACT

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.