Effects of the elevation of serum bile acids on gastric mucosal damage

In this study, we evaluated whether the elevated serum level of bile acids was a trigger of gastric mucosal damage in rats. A degree of mucosal injury was evaluated as an extent of ulcer formation due to HCl. That is, 0.6 N HCl was administered to the stomach via a tube in a rat model 3 h after ligation of the common bile duct, with additional infusion of four different bile acids. Taurocholic acid (TCA), taurodeoxycholic acid (TDCA), taurochenodeoxycholic acid (TCDCA) and tauroursodeoxycholic acid (TUDCA) were used as bile acid samples and saline was administered to rats as a control. Moreover, gastric mucosal blood Row and gastric content of epidermal growth factor (EGF), were evaluated in rats with severe mucosal damage. As a result, significant mucosal damage was detected in rats administered TDCA or TCDCA compared to controls. Gastric mucosal blood flow did not change, but the EGF level was significantly decreased by bile duct obstruction with TDCA infusion. These data indicate that gastric mucosal injury was readily induced by an elevated serum level of TDCA, TCDCA and their unconjugated bile salts and this effect was directly due to cytotoxicity of the bile acid. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.