These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effects of intraduodenal infusion of L-tryptophan on ad libitum eating, antropyloroduodenal motility, glycemia, insulinemia, and gut peptide secretion in healthy men.
    Author: Steinert RE, Luscombe-Marsh ND, Little TJ, Standfield S, Otto B, Horowitz M, Feinle-Bisset C.
    Journal: J Clin Endocrinol Metab; 2014 Sep; 99(9):3275-84. PubMed ID: 24926954.
    Abstract:
    CONTEXT: Changes in gut motor and hormonal function contribute to the eating-inhibitory and glucose-lowering effects of protein. The effect of amino acids, the digestive products of protein, on gastrointestinal function, eating, and glycemia has not been investigated comprehensively. OBJECTIVE: We tested the hypothesis that L-tryptophan (L-Trp) stimulates gastrointestinal motor and hormonal functions, inhibits eating, and modulates glycemia. Design, Settings, Participants, and Intervention: Ten healthy, normal-weight men were studied in randomized, double-blind fashion, each receiving a 90-minute intraduodenal infusion of L-Trp at 0.075 (total 6.75 kcal) or 0.15 (total 13.5 kcal) kcal/min or saline (control). MAIN OUTCOME MEASURES: Antropyloroduodenal motility, plasma ghrelin, cholecystokinin, glucagon-like peptide-1, peptide tyrosine tyrosine, insulin, glucagon, blood glucose, and appetite perceptions were measured. Food intake was quantified from a buffet meal after the infusion. RESULTS: Intraduodenal L-Trp suppressed antral pressures (P < .05) and stimulated pyloric pressures (P < .01) and markedly increased cholecystokinin and glucagon (both P < .001). Glucagon-like peptide-1 and peptide tyrosine tyrosine increased modestly (both P < .001), but there was no effect on total ghrelin. Insulin increased slightly (P < .05) without affecting blood glucose. Plasma L-Trp increased substantially (P < .001). All effects were dose-related and associated with increased fullness and substantially decreased energy intake (P < .001). There was a strong inverse correlation between energy intake and plasma L-Trp (r = -0.70; P < .001). CONCLUSIONS: Low caloric intraduodenal loads of L-Trp affect gut motor and hormonal function and markedly reduce energy intake. A strong inverse correlation between energy intake and plasma L-Trp suggests that, beyond gut mechanisms, direct effects of circulating L-Trp mediate its eating-inhibitory effect.
    [Abstract] [Full Text] [Related] [New Search]