Gastric mucosal damage by taurine and glycine conjugates of chenodeoxycholic acid

Bile damage to gastric mucosa may be demonstrated by means of changes in the transmucosal movement of H+ and Na+ ions. In the present study pure 10 mM solutions of taurine and glycine conjugates of chenodeoxycholic acid were instilled into canine Heidenhain pouches. Solutions were prepared at pH 2, 4, and 8, as previous work had shown a greater damaging effect at low pH. The present study confirmed this pH effect, but only with respect to movement of Na+ ion for taurine conjugates. The magnitude of the changes in ionic movements was much greater with pure bile acid solutions than that seen previously with whole bile. These findings are discussed. The greater damage seen below the pKa of the bile acid conjugates suggests that its nonionized form is the more damaging.