title: The functional involvement of gut-expressed sweet taste receptors in glucose-stimulated secretion of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY).
abstract: OBJECTIVE
  Enteroendocrine cells are thought to directly sense nutrients via α-gustducin coupled taste receptors (originally identified in the oral epithelium) to modulate the secretion of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY).
  
  
  METHODS
  We measured mRNA expression of α-gustducin and T1R3 along the human gut; immunohistochemistry was used to confirm co-localization with GLP-1. Functional implication of sweet taste receptors in glucose-stimulated secretion of GLP-1 and PYY was determined by intragastric infusion of glucose with or without lactisole (a sweet taste receptor antagonist) in 16 healthy subjects.
  
  
  RESULTS
  α-gustducin was expressed in a region-specific manner (predominantly in the proximal gut and less in ileum and colon, P < 0.05). Both, T1R3 and α-gustducin were co-localized with GLP-1. Glucose-stimulated secretions of GLP-1 (P = 0.026) and PYY (P = 0.034) were reduced by blocking sweet receptors with lactisole.
  
  
  CONCLUSIONS
  Key proteins implicated in taste signaling are present in the human gut and co-localized with GLP-1 suggesting that these proteins are functionally linked to peptide secretion from enteroendocrine cells. Glucose-stimulated secretion of GLP-1 and PYY is reduced by a sweet taste antagonist, suggesting the functional involvement of gut-expressed sweet taste receptors in glucose-stimulated secretion of both peptides in humans.
authors.affiliation: Clinical Research Center, Department of Biomedicine, Switzerland. robert.steinert@unibas.ch
authors.forename: R E
authors.initials: RE
authors.lastname: Steinert
authors.forename: A C
authors.initials: AC
authors.lastname: Gerspach
authors.forename: H
authors.initials: H
authors.lastname: Gutmann
authors.forename: L
authors.initials: L
authors.lastname: Asarian
authors.forename: J
authors.initials: J
authors.lastname: Drewe
authors.forename: C
authors.initials: C
authors.lastname: Beglinger
mesh_terms: D000328:Adult; D000368:Aged; D001555:Benzene Derivatives / Q000008:administration & dosage; D003106:Colon / Q000187:drug effects*; D019858:Enteroendocrine Cells / Q000378:metabolism; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000235:genetics / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007082:Ileum / Q000187:drug effects*; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D019894:Peptide YY / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D013649:Taste; D015293:Transducin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D001555:Benzene Derivatives; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C431926:taste receptors, type 1; D019894:Peptide YY; D052216:Glucagon-Like Peptide 1; D015293:Transducin; D005947:Glucose; C495512:lactisole