Human postprandial gastric emptying of indigestible solids can occur unrelated to antral phase III

According to animal experiments, postprandial gastric emptying of indigesti ble solids is mainly related to the antral phase III activity of the migrat ing motor complex. Gastric emptying of indigestible solids in humans has no t been directly correlated to pressure recordings. The aim of the present s tudy was to investigate the postprandial emptying pattern of indigestible s olids in humans and its relation to fed and fasted antral motility. Ten hea lthy volunteers participated. After an overnight fast they had a standard b reakfast. Two sizes of radiopaque markers (ROMs) were given with the test m eal; ten cubes each of side measurement 1.5 mm and 3 mm, respectively. Empt ying of the ROMs from the stomach was followed by fluoroscopy with simultan eous antral manometry In six of the subjects, fasting antral manometry was performed on one day and on another day, the emptying of 7 mm cylindrical p articles together with 3 mm cubes, in the absence of a gastric tube was rec orded. All ROMs were emptied within 5 h (range 1.5-4.5 h). In all subjects, the smaller particles (1.5 mm) showed a slight, insignificant tendency to move from the stomach more rapidly than the larger (3 mm) particles. None o f the subjects had an antral phase III before all ROMs were emptied from th e stomach. Instead, the typical irregular postprandial pressure activity wa s present in all subjects until the emptying was completed. Furthermore, th e highest postprandial motility index during the emptying study was far bel ow the motility index during phase III, but comparable 50 the motility inde x during late phase II. Emptying of the 7 mm particles occurred significant ly more slowly at 1.5-2.5 h, but otherwise was similar to the emptying of t he smaller particles. There was no difference between emptying of the 3 mm cubes with or without the presence of the tube. Contrary to common opinion, gastric emptying of indigestible solids after a meal can occur unrelated t o the antral phase III, at least up to a particle size of 3 mm and perhaps even 7 mm. These findings are of great importance for the evaluation of gas tric emptying of indigestible solids, including the pharmacodynamics of ora lly administered drugs.