Effect of peptic digestion on emptying of cooked liver in dogs

By speeding the fragmentation of meat, peptic digestion might accelerate gastric emptying. To examine this possibility, mongrel dogs prepared with chronic duodenal fistulas were fed steak and 99mTc-labeled chicken liver, measuring 99mTc in all chyme exiting from the stomach out the duodenal fistula allowed quantitation of the gastric emptying of 99mTc-liver. Emptying was studied during relatively uninhibited gastric propulsion when the proximal bowel was perfused with chyme or fat. When chyme was diverted, the speed of emptying varied with peptic activity in the stomach--that is, it was increased by orogastric perfusion with acid-pepsin (vs. a control perfusion of pH 7 buffer) or, alternately, was decreased from the unperfusion stomach by i.v. cimetidine (vs. i.v. saline). By contrast, no effect of altering peptic conditions was observed when chyme was allowed access to the proximal bowel (the more normal situation), or when the duodenum was perfused with fat. We conclude that duodenal inhibition may override the effect of peptic digestion on the emptying of liver. We postulate that inhibition of gastric contractions limits the grinding of liver into particles susceptible to peptic digestion.