Effects of nutrient liquids on human gastroduodenal motor activity

The effects of intragastric infusion of 10% Intralipid and 10% dextrose on the intraluminal pressures in the antrum, pylorus and duodenal bulb have been examined. Ten studies with each infusate have been performed in 10 normal subjects and the results compared with those obtained previously in 22 studies during intragastric infusion of isotonic saline. During saline infusion, contractile activity varied. In six studies fasting motor activity persisted; in the remainder, variable activity, without recognisable pattern was recorded. With saline, the gastroduodenal region usually functioned as a unit and the pylorus was the least autonomous part. Neither a sustained rise of basal pressure nor rhythmic, independent contractions were recorded from the pylorus. The contractile activity of the gastroduodenal region with Intralipid and dextrose was more uniform than with saline. Fasting motor activity was always abolished. The gastroduodenal region ceased to contract as a unit and the pylorus acquired autonomous activity. Rhythmic, independent contractions of the pylorus were recorded in nine of 10 studies during Intralipid infusion and six of 10 studies with dextrose. In addition, a sustained rise in pyloric basal pressure was recorded in eight of 10 studies with Intralipid and three of 10 studies with dextrose. Pyloric motility indices were significantly greater with fat than with dextrose. The observed differences in gastroduodenal motility are consistent with a role for the pylorus in the control of emptying of liquid from the stomach.