THERMODYNAMIC EFFECTS OF BILE-ACIDS IN THE STOMACH

The surface thermodynamic effects of bile acids in the stomach were assessed in 48 subjects who had undergone gastric surgery for peptic ulcer disease and in 52 controls with medically healed ulcers. We derived values for surface tension of gastric mucosa from contact angle using a goniometer and measured the surface tension of gastric juice by the drop-weight method. Subjects with gastric surgery had higher median fasting bile acid concentrations than controls (1.2 vs. 0.1 mmol/L; P < 0.0001), higher mean mucosal surface tension (51.9 vs. 47.9 mN/m; P < 0.0001), and lower mean surface tension of gastric juice (43.2 vs. 51.7 mN/m; P < 0.0001). Subjects who had had a Billroth II gastrectomy (n = 19) had higher bile acid concentrations (5.8 vs. 0.6 mmol/L; P < 0.01), higher mucosal surface tension (53.7 vs. 50.3 mN/m; P < 0.05), and lower gastric juice surface tension (41.3 vs. 47.1 mN/m; P < 0.05) than those who had a vagotomy and drainage procedure (n = 17). Overall, intragastric bile acid concentration correlated directly with surface tension of gastric mucosa (r = 0.51, P < 0.0001) and inversely with that of gastric juice (r = -0.60, P < 0.0001). In conclusion, the interfacial energy barrier at the surface of the gastric mucosa is overcome in the presence of intragastric bile acids. © 1990.