[Electrophysiological changes related to the exclusion of bile from the small intestine of dogs during the interdigestive period].

The effect of interruption of enterohepatic circulation of bile acids on the interdigestive electrical activity of gastrointestinal tract was studied on 6 dogs. Animals underwent the functional cholecystectomy and cannulation of common bile duct. 9 bipolar electrodes were then implanted into the stomach and small intestine. Electrical activity was recorded during 2-3 and 4-10 hr periods of bile diversion with and without intravenous infusion of sodium taurocholate and also during intraduodenal bile acid infusions. In control group the enterohepatic circulation of bile acids was maintained. During longer bile diversion intervals of the myoelectric cycle increased from 104 +/- 7 min in control group till 133 +/- 8 min (P less than 0.05) mainly due to the prolongation of phase II. During the latter period a specific pattern of spike bursts (bile diversion myoelectric pattern, BDMP) was observed. This phenomenon was induced by the lack or deficiency in bile acids in the intestinal lumen (the bile acid depletion pattern, BADP) and it was inhibited during bile acid administration. When the biliary drainage was continued, 82% of an activity fronts originated in the jejunum. Their propagation velocities in upper jejunum were 9 +/- 1 cm.min-1 as compared to the control value, 6 +/- 0.05 cm.min-1 (P less than 0.05). These changes were approximate to those observed during intravenous taurocholate infusion. However, the cycle duration lasting 90 +/- 9 min was not significantly altered and BADP was less frequently recorded. The results obtained confirm the significant role of bile and bile diversion in modification of the myoelectric activity of stomach and small bowel in dogs.