Changes in the interstitial cells of Cajal in the gallbladder of guinea pigs fed a lithogenic diet.

Cholesterol cholelithiasis is a common disease and gallbladder hypomotility may underlie its pathogenesis. Interstitial cells of Cajal (ICCs) in the gallbladder serve vital roles in regulating gallbladder motility. The aim of the present study was to investigate changes in gallbladder ICCs during the development of cholesterol cholelithiasis. A total of 40 male guinea pigs were randomly assigned to four groups and fed a standard diet (SD) or lithogenic diet (LD) for 2 or 8 weeks. The LD significantly increased the total cholesterol levels in the serum and bile, as well as the serum levels of high-density lipoprotein-cholesterol and low-density lipoprotein-cholesterol after 2 and 8 weeks. The LD also significantly increased and decreased the number of gallbladder ICCs at 2 and 8 weeks, respectively, by regulating the stem cell factor/C-kit pathway. Moreover, the ultrastructure of gallbladder ICCs was significantly altered after 8 weeks, and the protein expression levels of connexin 43 in the gallbladder were differentially altered after 2 and 8 weeks. Finally, cholecystokinin receptor type A (CCK1R) expression in the gallbladder was assessed. In gallbladder ICCs, its expression was significantly increased and decreased after 2 and 8 weeks, respectively. In conclusion, these results demonstrate that the density, ultrastructure and CCK1R expression levels of gallbladder ICCs are differentially altered at various stages of cholesterol cholelithiasis progression, indicating that gallbladder ICCs may be considered a potential therapeutic target for treatment of cholesterol cholelithiasis.