The duodenojejunal junction and Treitz ligament in the regulation of duodenal emptying.

In chronic experiments in dogs the evacuatory and absorptive duodenal functions and the level of duodenogastric reflux (DGR) in sham-operated dogs and dogs with transected Treitz ligament (TL) and resected duodenojejunal junction (DJJ) were studied. The electrophysiologic characteristics of the antrum, duodenum, and DJJ in sham-operated dogs were examined. It was shown that there is a coordination of gastric and duodenal solid carbohydrate food emptying. The process of evacuation from both organs was characterized by three closely correlated phases, phase 2 of emptying being exponential. In the TL transection and DJJ resection groups the coordination of gastric and duodenal emptying disappeared. The rate of carbohydrate solid food evacuation from the duodenum decreased, on average, by 45.5% +/- 5.5% (P < 0.05); phase 2 of duodenal emptying became unexponential, and the level of DGR considerably increased. The rate of duodenal absorption of main organic chyme components increased significantly in most of the time intervals studied. Significantly higher amplitudes of slow waves and spike potentials were recorded from the DJJ than from the duodenum. We conclude that the DJJ and TL are possible regulators of duodenal emptying. The DJJ is probably a functional sphincter that provides coordinated activity of the stomach and duodenum.