Abstract: ObjectivesTo investigate the role and the mechanism of gallbladder wall thickening in gallstone formation. MethodsA total of 40 healthy adult guinea pigs were selected and randomly divided into a gallstone group fed by lithogenous diet and a control group fed by normal diet. The gallbladder wall thickness, gallbladder emptying rate and the formation of gallstones were examined by B-scan ultrasonography every 2-3 days. The gallbladder specimens were collected after 8 weeks of feeding in order to observe the formation of gallstone and determine the contraction of the gallbladder. Further methods including paraffin embedding, slicing and H-E staining were also used to observe the histopathological changes of the gallbladder and measure the gallbladder wall thickness. The levels of type I collagen, connective tissue growth factor (CTGF), insulin-like growth factors (IGF-1) mRNA and protein in gallbladder tissues were detected by PCR and Western blotting, respectively. ResultsCompared with the control, the gallbladder wall was significantly thickened in the gallstone group with remarkably reduced muscular contraction. The gallstone group also produced higher levels of type I collagen, CTGF, IGF-1 mRNA and protein in gallbladder tissue in the gallbladder wall then the control. ConclusionsGallbladder wall thickening which leads to decreased gallbladder motility is an important cause of gallstone formation, which is related to the fibrosis of the gallbladder wall.