Antropyloroduodenal motor responses to intraduodenal lipid infusion in healthy volunteers

Abstract

The delivery of lipid to the duodenum has been shown to slow gastric emptying and to increase the resistance to gastric outflow. To investigate mechanisms responsible for these effects, we have recorded antropyloroduodenal motility in nine healthy volunteers during alternate intraduodenal infusions of normal saline and triglyceride emulsion (Intralipid 10%). During the lipid infusions there were reproducible, major changes in the patterns of motility. Pressure waves, apparently isolated to the pylorus, usually started within 10 min of initiation of the lipid infusion. After 20-25 min of lipid infusion these waves occurred at median rates of 2.4 and 2.8/min (1st and 2nd lipid infusions, respectively); these rates were significantly greater (P less than 0.05) than the median rates (all less than or equal to 0.4/min) observed during the equivalent period of the succeeding saline infusions. During 10 of 22 lipid infusions, isolated pyloric pressure waves were associated with sustained pyloric tone. Infusion of lipid into the duodenum suppressed antral pressure waves in all subjects and initiated brief periods of regular duodenal contractions during 11 of 22 infusions. These studies have demonstrated alterations of antropyloroduodenal motor patterns in response to changes in the duodenal luminal content. The effects on antral and pyloric motility are probably of importance in the regulation of transpyloric flow by nutrients in the duodenal lumen.

Effects of dipeptidyl peptidase IV inhibition on glycemic, gut hormone, triglyceride, energy expenditure, and energy intake responses to fat in healthy males

“…On each visit, participants arrived at the Discipline of Medicine at 0800, where a silicone catheter with antral and duodenal sideholes perfused with saline, and a terminal infusion port, was inserted through an anesthetized nostril in the stomach and allowed to pass into the duodenum (16). Catheter position was monitored by measurement of the transmucosal potential difference in the stomach and duodenum (16), using a saline-filled subcutaneous cannula placed in the left forearm as a reference electrode (16).…”

“…Catheter position was monitored by measurement of the transmucosal potential difference in the stomach and duodenum (16), using a saline-filled subcutaneous cannula placed in the left forearm as a reference electrode (16). Once the catheter was positioned correctly with the infusion port 14.5 cm distal to the pylorus, fasting resting energy expenditure (REE) and respiratory quotient (RQ) were measured over 30 min by indirect calorimetry, using a clear ventilated hood and the TrueOne 2400 metabolic monitoring system (Parvo Medics, East Sandy, UT).…”

Effect of the artificial sweetener, sucralose, on gastric emptying and incretin hormone release in healthy subjects

“…For example, the suppression of energy intake induced by small intestinal fat infusion is much greater than that in response to an equivalent intravenous fat load (46). Exposure of the small intestine to nutrients is also associated with feedback inhibition to slow the rate of gastric emptying (4,20). Both the slowing of gastric emptying and suppression of appetite are mediated by the secretion of gastrointestinal hormones, including glucagon-like peptide-1 (GLP-1) (26,40), the release of which is strongly stimulated by carbohydrate (23).…”

Effects of intravenous fructose on gastric emptying and antropyloroduodenal motility in healthy subjects

“…The motor correlates of the slowing of gastric emptying induced by the presence of nutrients in the small intestine include relaxation of the proximal stomach (2), suppression of antral motility (22), and stimulation of phasic and tonic pyloric contractions (23). Monosaccharides empty from the stomach more slowly than water or isotonic saline because of small intestinal feedback (17), but there may be subtle differences between them.…”