A NEW MODEL FOR PANCREATICOBILIARY MALJUNCTION WITHOUT BILE-DUCT DILATATION - DEMONSTRATION OF CELL-PROLIFERATION IN THE GALLBLADDER EPITHELIUM

Patients with pancreaticobiliary maljunction without bile duct dilatat ion (PBMWBDD) develop gallbladder carcinoma frequently. No models of P BMWBDD exist, and no previous studies have clearly demonstrated change s in the gallbladder relating to carcinogenesis. We, therefore, examin ed the cell kinetics of the gallbladder epithelium in a new experiment al model of PBMWBDD. A cat model was produced by performing choledocho -pancreatic side-to-side ductal anastomosis in nine animals. Five cats , in which the choledocho pancreatic ducts were exposed only, served a s controls. After 6 months, the gallbladders of these cats were remove d and stained with anti-proliferating cell nuclear antigen (PCNA) anti body (PC10, Dako). The labeling index (LI) was determined from the per centage of positive nuclei in three microscopic fields. The diameter o f the common bile duct was not different between the models and the co ntrols. In the models, the number of PCNA positive cells was significa ntly increased. The mean (+/- standard deviation) PCNA LI was 28.1 +/- 12.2% in the models and 4.3 +/- 1.6% in the controls (P < 0.01). Thes e studies clearly indicate that this model is suitable for studying PB MWBDD and that PBMWBDD has a prominent proliferating effect on the gal lbladder epithelium which may play an important role in gallbladder ca rcinogenesis. (C) 1996 Academic Press, Inc.