Interstitial cells of Cajal in the murine gallbladder

Abstract
The presence of interstitial cells of Cajal (ICC) has been described throughout the digestive tract. In this study, we investigated whether ICC also exist in the gallbladder wall of CD1 mice. Immunofluorescent confocal microscopy was used to identify the morphology and distribution of ICC in either whole-mount flat preparations or enzyme-dispersed cells from the gallbladder of CD1 mice. Methylene blue staining and transmission electron microscopy were performed to detect the presence of ICC, and reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to confirm the expressions of ICC-specific marker c-kit in the gallbladder tissues. The presence of c-kit-positive cells was demonstrated in both the gallbladder wall and the enzyme-dispersed cells. The ICC were distributed throughout the wall of the gallbladder and organized into a network. Under transmission electron microscopy, ICC were characterized by their well-developed perinuclear endoplasmic reticulum, abundant mitochondria, free ribosomes and intermediate filaments, and distinctive caveolae and lack of myosin filaments. The expressions of ICC-specific marker c-kit were also confirmed in the gallbladder tissue. The murine gallbladder wall contains ICC.