Inhibition of Gastric Motility by Duodenal Contents in Turkeys

Twenty young turkeys were prepared with two fistulas in the duodenum, one at the flexure and a second in the distal duodenum. Pressures were measured and recorded in the glandular and muscular stomachs and in the duodenal flexure by means of open-tipped polyethylene tubes connected to pressure transducers. Several stimuli were applied to the mucosa of the distal duodenum while recording. Corn oil, mineral oil, hypertonic and isotonic solutions, and dilute HCl were injected, and balloons were inflated, within the distal duodenum. Inhibition of gastric motility was evident within seconds after injection of 4 to 10 ml. of 0.1N HCl and 6 to 12 ml. of 1600 mOsM NaCl solutions or after balloon inflation. Within minutes after an injection of 6–12 ml. of corn oil the frequency of gastric contractions was slowed. Mineral oil (10 ml.) did not inhibit motility. Sufficiently large quantities of neutral isotonic saline (>30 ml.) slightly depressed normal gastric motility. Recorded pressure changes characteristic of intestinal refluxes were observed frequently during most of the responses to these stimuli. It is hypothesized that the inhibition of gastric motility which occurs within seconds after application of an intraduodenal stimulus may be the result of a neural mechanism while that caused by the injection of corn oil may be humorally mediated.