IMMUNOHISTOCHEMICAL STUDY OF THE C-KIT EXPRESSING CELLS AND CONNEXIN-43 IN THE GUINEA-PIG DIGESTIVE-TRACT

The distribution of the c-kit receptor expressing cells and gap juncti on protein, connexin (Cx) 43 in the guinea-pig stomach (antrum), small intestine (jejunum) and colon (ascending) was studied by immunohistoc hemistry. The anti-c-kit protein immunopositive cells were regularly o bserved in the myenteric region throughout all three organs. The immun opositive cells were also sparsely distributed in the circular muscle layer of both the stomach and the colon, but not in the small intestin e. They were densely located in the regions of the deep muscular plexu s (DMP) of the small intestine and submuscular plexus (SMP) of the col on. In contrast, strong immunoreactivity to anti-Cx 43 antibody was ob served in almost the entire thickness of the circular muscle layer of the stomach and the small intestine, but not in the colon. Dense immun oreaction deposits were observed in the region of the DMP and SMP. How ever, only very weak immunoreactivity to anti-Cx 43 antibody was detec ted in the myenteric region of all three organs. These results suggest that the c-kit receptor expressing cells or interstitial cells of Caj al (ICC) in the myenteric region of the three organs, and in the SMP o f the colon, are poorly coupled with the bulk of circular muscle tissu e by gap junctions, while ICC in the DMP and in the circular muscle la yer of the stomach couple well with the surrounding muscle tissue. (C) 1998 Elsevier Science B.V.