the relation between intragastric distribution and gastric emptying in human volunteers

The relation between gastric emptying and the intragastric distribution of300 ml radiolabelied beef consomme with and without 60 g margarine was investigated by performing randomised, paired gammacamera studies in seven healthy male volunteers (aged 20-22 years). The low calorie bland meal emptied rapidly from both the proximal and distal stomach after a short lag period (4-6 min), during which 24-50% of the liquid passed into the distal stomach. Addition of margarine to the liquid test meal increased the lag period (median 32 min, range 7-60 min; p<001) and decreased the slope of emptying (T1⁄2/2 lag period 88 min, 49-146 min v 15 min, 10-57. min; p<001). During the lag period there was an initial filling of the distal stomach, similar to that with the bland liquid, followed by a redistribution of between 19% and 61% (median 46%) of the distal stomach contents back into the proximal stomach. At the onset of emptying, the distal stomach filled (median 30%, range 16-34%) and during this time the proximal stomach emptied twice as fast as the whole stomach (p<005). Thereafter, the distal stomach capacity remained relatively constant while both the proximal and whole stomach emptied at similar rates. This study shows that the delay in gastric emptying of a liquid that has a high fat content is due in part to a redistribution of distal stomach contents back into the proximal stomach. Sub-Department of Gastrointestinal Physiology and Nutrition and Department of Surgery, University of Sheffield, Sheffield S10 2JF L A Houghton Y F Mangnall N W Read Correspondence to: Dr L A Houghton, Sub-Dept of Gastrointestinal Physiology and Nutrition, University of Sheffield, Royal Hallamshire Hospital, Sheffield S10 2JF. Accepted for publication 18 December 1989 It is generally thought that contraction of the gastric fundus is responsible for the emptying of liquids from the stomach, whereas antral contractions control the emptying of solids."2 The evidence for the predominant role of the fundus in the emptying of liquids from the stomach comes from the results of surgical operations. Resection of the fundus3 or vagal denervation of the proximal stomach4 in the dog increases intragastric pressure and hastens the emptying of liquid meals. In the intact stomach fundic tone is greater during the emptying of saline liquid test meals than liquid test meals that contain a high proportion of fat,5 but a pressure gradient between the stomach and duodenum has never been shown. Manometric and scintigraphic observations in humans and dogs suggest that bland liquids empty in gushes associated with coordinated contractions of the antrum and duodenum.67 Moreover, when gastric emptying is delayed by increasing the fat content of a liquid there is suppression of antral contractions,89 enhancement of phasic and tonic pyloric activity,8'10 and relaxation of the fundus.5 " The importance, however, of each of these components in the emptying of liquid meals of high and low lipid content is unclear. This study attempts to elucidate the relative roles of the proximal and distal stomach in retarding gastric emptying of liquid meals of high lipid content by analysing the distribution of radioactive counts in the proximal and distal stomach.