title: Comparative effects of intraduodenal protein and lipid on ghrelin, peptide YY, and leptin release in healthy men.
abstract: Intraduodenal infusion of lipid or protein potently reduces subsequent energy intake. There is evidence that the underlying mechanisms differ significantly between the two nutrients. While intraduodenal lipid stimulates glucagon-like peptide-1 and CCK much more than protein, the release of insulin and glucagon is substantially greater in response to protein. Ghrelin and PYY are both involved in short-term regulation, while leptin is a long-term regulator, of energy balance; the acute effects of nutrients on leptin release are unclear. We investigated the comparative effects of intraduodenal lipid and protein on plasma ghrelin, PYY, and leptin concentrations. Thirteen lean, young men received 90-min intraduodenal infusions of protein (whey hydrolysate) or lipid (long-chain triglyceride emulsion) at a rate of 3 kcal/min, or saline control, on three separate days. Blood samples were collected at baseline and regularly during infusions. Both lipid and protein potently suppressed plasma ghrelin compared with control (both P < 0.001), with no difference between them. While both lipid and protein stimulated plasma PYY (P < 0.001), the effect of lipid was substantially greater than that of protein (P < 0.001). Neither intraduodenal lipid nor protein affected plasma leptin. In conclusion, intraduodenal lipid and protein have discrepant effects on the release of PYY, but not ghrelin. When considered with our previous findings, it appears that, with the exception of ghrelin, the energy intake-suppressant effects of lipid and protein are mediated by different mechanisms.
authors.affiliation: University of Adelaide Discipline of Medicine, Adelaide, Australia; National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia;
authors.forename: Sina S
authors.initials: SS
authors.lastname: Ullrich
authors.affiliation: Medizinische Klinik, Klinikum Innenstadt, University of Munich, Munich, Germany; and.
authors.forename: Bärbel
authors.initials: B
authors.lastname: Otto
authors.affiliation: University of Adelaide Discipline of Medicine, Adelaide, Australia; National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia;
authors.forename: Amy T
authors.initials: AT
authors.lastname: Hutchison
authors.affiliation: University of Adelaide Discipline of Medicine, Adelaide, Australia; National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia; Food, Nutrition and Bioproducts Flagship, Commonwealth Scientific and Industrial Research Organization, Adelaide, Australia.
authors.forename: Natalie D
authors.initials: ND
authors.lastname: Luscombe-Marsh
authors.affiliation: University of Adelaide Discipline of Medicine, Adelaide, Australia; National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia;
authors.forename: Michael
authors.initials: M
authors.lastname: Horowitz
authors.affiliation: University of Adelaide Discipline of Medicine, Adelaide, Australia; National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia; christine.feinle@adelaide.edu.au.
authors.forename: Christine
authors.identifier: http://orcid.org/0000-0001-6848-0125
authors.initials: C
authors.lastname: Feinle-Bisset
mesh_terms: D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D004311:Double-Blind Method; D004386:Duodenum / Q000187:drug effects* / Q000378:metabolism; D004435:Eating; D004734:Energy Metabolism; D054439:Ghrelin / Q000097:blood*; D064368:Healthy Volunteers; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D008894:Milk Proteins / Q000008:administration & dosage*; D019894:Peptide YY / Q000097:blood*; D019518:Postprandial Period; D011492:Protein Hydrolysates / Q000008:administration & dosage*; D013997:Time Factors; D014280:Triglycerides / Q000008:administration & dosage*; D000067816:Whey Proteins; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D004044:Dietary Proteins; C515349:GHRL protein, human; D054439:Ghrelin; D020738:Leptin; D008894:Milk Proteins; D011492:Protein Hydrolysates; D014280:Triglycerides; D000067816:Whey Proteins; D019894:Peptide YY
keywords: food intake; gastrointestinal function; gut hormones; humans