A comparison of duodenal osmolality and energy content as controlling factors of gastric emptying in the calf.

1. The relative importance of energy content and osmolality of the duodenal chyme in the feed-back control of gastric emptying was investigated in the milk-fed calf fitted with gastric (abomasal) and duodenal re-entrant cannulae. 2. Duodenal infusion of isosmolal solutions, containing glucose, fructose or galactose, with a range of combustible energy content (0--1.46 MJ/l.) resulted in the same high rate of emptying of test meals from the stomach (abomasum). Abomasal emptying was, therefore, not affected by the energy content of the duodenal infusate. 3. Gastric secretion of acid and pepsinogen, and the volume of gastric secretions produced were also unaffected by the energy content of isosomolal duodenal infusates. 4. The results of the study show that the combustible energy content of the intestinal chyme is not a direct determinant of gastric function and that total osmolality of the lumenal contents is the only parameter influencing duodenal receptors under the conditions of our experiments.