Effects of Intraduodenal Infusions of L-phenylalanine and L-glutamine on Antropyloroduodenal Motility and Plasma Cholecystokinin in Healthy Men.
- Author:
Robert E STEINERT
1
;
Maria F LANDROCK
;
Michael HOROWITZ
;
Christine FEINLE-BISSET
Author Information
- Publication Type:Randomized Controlled Trial ; Original Article
- Keywords: Amino acids; Eating; Gastrointestinal hormones; Gastrointestinal motility; Humans
- MeSH: Amino Acids; Cholecystokinin*; Cross-Over Studies; Dietary Proteins; Eating; Gastric Emptying; Gastrointestinal Hormones; Gastrointestinal Motility; Glutamine*; Humans; Male; Phenylalanine*; Plasma*
- From:Journal of Neurogastroenterology and Motility 2015;21(3):404-413
- CountryRepublic of Korea
- Language:English
- Abstract: BACKGROUND/AIMS: Dietary proteins have potent eating-inhibitory and glucose-lowering effects, which may be mediated via effects of amino acids on gastrointestinal hormone and motor function, although little information is available. We have now evaluated the effects of L-phenylalanine (L-Phe) and L-glutamine (L-Gln) on antropyloroduodenal motility and plasma cholecystokinin (CCK) concentrations. METHODS: Two double-blind, 3-way cross-over studies were performed, each including 10 healthy, normal-weight men. We determined the antropyloroduodenal motor and plasma CCK responses to 90-minute intraduodenal infusions of L-Phe (study A) or L-Gln (study B), each at 0.15 kcal/min (total 13.5 kcal), or 0.45 kcal/min (total 40.5 kcal), or saline (control), in randomized fashion. RESULTS: Intraduodenal L-Phe at 0.45 kcal/min, but not at 0.15 kcal/min, suppressed antral (P < 0.01), and stimulated phasic (P < 0.01), but not tonic, pyloric, or duodenal pressures, while L-Phe at both 0.15 kcal/min and 0.45 kcal/min stimulated plasma CCK. In contrast, L-Gln had no effect on antral, duodenal or pyloric pressures, or plasma CCK. CONCLUSIONS: Intraduodenal infusions of L-Phe and L-Gln, in doses of 0.15 kcal/min and 0.45 kcal/min for 90 minutes, have different effects on antropyloroduodenal motility and CCK in normal-weight men. The modulation of antral and pyloric pressures and CCK may contribute to the eating-inhibitory effects of oral L-Phe, possibly through the slowing of gastric emptying.
