title: The role of lipolysis in human orosensory fat perception.
abstract: Taste perception elicited by food constituents and facilitated by sensory cells in the oral cavity is important for the survival of organisms. In addition to the five basic taste modalities, sweet, umami, bitter, sour, and salty, orosensory perception of stimuli such as fat constituents is intensely investigated. Experiments in rodents and humans suggest that free fatty acids represent a major stimulus for the perception of fat-containing food. However, the lipid fraction of foods mainly consists of triglycerides in which fatty acids are esterified with glycerol. Whereas effective lipolysis by secreted lipases (LIPs) liberating fatty acids from triglycerides in the rodent oral cavity is well established, a similar mechanism in humans is disputed. By psychophysical analyses of humans, we demonstrate responses upon stimulation with triglycerides which are attenuated by concomitant LIP inhibitor administration. Moreover, lipolytic activities detected in minor salivary gland secretions directly supplying gustatory papillae were correlated to individual sensitivities for triglycerides, suggesting that differential LIP levels may contribute to variant fat perception. Intriguingly, we found that the LIPF gene coding for lingual/gastric LIP is not expressed in human lingual tissue. Instead, we identified the expression of other LIPs, which may compensate for the absence of LIPF.
authors.affiliation: Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, 14558 Nuthetal, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Voigt
authors.forename: Julia
authors.initials: J
authors.lastname: Stein
authors.forename: Maria Mercedes
authors.initials: MM
authors.lastname: Galindo
authors.forename: Andreas
authors.initials: A
authors.lastname: Dunkel
authors.forename: Jan-Dirk
authors.initials: JD
authors.lastname: Raguse
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Meyerhof
authors.forename: Thomas
authors.initials: T
authors.lastname: Hofmann
authors.forename: Maik
authors.initials: M
authors.lastname: Behrens
mesh_terms: D000328:Adult; D004041:Dietary Fats / Q000494:pharmacology*; D004951:Esterification; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D007783:Lactones / Q000494:pharmacology; D008049:Lipase / Q000235:genetics / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects; D008297:Male; D019301:Oleic Acid / Q000737:chemistry / Q000494:pharmacology; D000077403:Orlistat; D012463:Saliva / Q000187:drug effects / Q000378:metabolism; D012469:Salivary Glands / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D055697:Taste Perception / Q000187:drug effects*; D014304:Triolein / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004041:Dietary Fats; D007783:Lactones; D014304:Triolein; D019301:Oleic Acid; D000077403:Orlistat; D008049:Lipase
keywords: G protein-coupled receptor; free fatty acid; lipase; taste; triglyceride; von Ebner’s gland