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dc.contributor.advisorOlszewski, Pawel K.
dc.contributor.authorAidney, Fraser Charles
dc.date.accessioned2016-09-22T03:25:25Z
dc.date.available2016-09-22T03:25:25Z
dc.date.issued2016
dc.identifier.citationAidney, F. C. (2016). Dietary supplementation and intragastric infusions of L-tryptophan reduce food intake (Thesis, Master of Science (Research) (MSc(Research))). University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/10642en
dc.identifier.urihttps://hdl.handle.net/10289/10642
dc.description.abstractSelect free amino acids have been suggested to promote early satiation. Initial studies indicate that L-tryptophan may play an important role in reducing appetite. The current set of experiments examined whether dietary and intragastrically administered L-tryptophan decreases food consumption and whether this effect is specific to eating stimulated by energy (calorie) needs or by pleasant taste (reward). A link between a satiating action of L-tryptophan and activity of the anorexigenic oxytocin circuit has also been investigated. Supplementation of milk formula-based diets with tryptophan reduced energy deprivation-induced consumption of these formulas in mice. Tryptophan enrichment had no effect on water intake, which precludes the involvement of taste- or thirst-related mechanisms in tryptophan-driven hypophagia. Intragastrically administered L-tryptophan decreased deprivation-induced chow intake. It also reduced hedonics-driven consumption of palatable saccharin and milk, but not of sucrose solutions in non-deprived mice, suggesting a link with feeding reward mechanisms unrelated to sucrose. Finally, oxytocin receptor blockade with very low doses of an antagonist just prior to intragastric L-tryptophan administration, completely abolished early termination of deprivation-induced food intake by this amino acid. Overall, the data indicate that dietary supplementation and intragastric delivery of free L-tryptophan reduce eating behaviour stimulated by energy needs and palatability, and that the effect of L-tryptophan is mediated by the anorexigenic oxytocin system.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.publisherUniversity of Waikato
dc.rightsAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectL-tryptophan
dc.subjectAppetite
dc.subjecthypophagia
dc.titleDietary supplementation and intragastric infusions of L-tryptophan reduce food intake
dc.typeThesis
thesis.degree.grantorUniversity of Waikato
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (Research) (MSc(Research))
dc.date.updated2016-03-18T00:47:13Z
pubs.place-of-publicationHamilton, New Zealand


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