In vitro cytolytic activity of gastric juice from patients with different fasting intragastric bile acid concentrations

Abstract

Objective. Evaluation of the cytolytic effect of intragastric bile acids collected from postoperative patients with different degrees of duodenogastric reflux. Patients and Methods. The study included 60 patients, 26 of whom had undergone cholecystectomy for gallstones (group A), while the other 34 had undergone a Billroth II gastric resection for peptic ulcer disease (group B). Intragastric bile acid concentration was evaluated after a 12-h fast by drainage of gastric contents every 15 min for 1 h using a nasogastric tube. The total bile acid (TBA) concentrations were measured by an enzymatic method. Cytotoxicity of gastric juice was assessed by haemolysis of human erythrocytes and expressed as ü of gastric juice required for 50% haemolysis (C50). Results. Group B patients had higher intragastric TBA levels than those from group A (P< 0.05). This was paralleled by the significantly greater in vitro cytolytic activity exhibited by gastric juice from group B compared with group A patients (P<0.05). There was a negative correlation between TBA levels in gastric juice and C50 values; there was no correlation between pH and C50 values. Conclusions. Our study has demonstrated that gastric juice collected from patients who have undergone cholecystectomy or gastric resection has different cytolytic activity, and that there is a significantly positive, but not absolute, correlation between the intragastric TBA concentration and lytic activity, suggesting that other factors also interact with intragastric TBAs to determine their lytic activity.