title: Unsaturated aldehydes induce CCK secretion via TRPA1 in STC-1 cells.
abstract: METHODS
  Cholecystokinin (CCK) producing cells sense luminal contents to regulate the exocrine pancreas, gastric motility, and appetite. Although long-chain fatty acids (FAs, ≥ C12) are well known to stimulate CCK secretion, the CCK-releasing activities of other aliphatic compounds, such as aldehydes (Alds) or alcohols (Alcs), have not been studied.
  
  
  RESULTS
  We tested the CCK-releasing activities of various aliphatic compounds with various carbon chain lengths (C3-C13) and degrees of unsaturation in the enteroendocrine cell line STC-1. CCK released from the cell was measured using an ELISA, and intracellular calcium concentration was measured using Fura-2. Mono- and di-unsaturated Alds at 100 μM, but not saturated Alds, induced CCK secretion in STC-1 cells. Alcs and FAs failed to induce CCK secretion, regardless of carbon chain length or degree of unsaturation. Unsaturated Alds increased intracellular calcium concentration, but saturated Alds, Alcs, and FAs did not. Intracellular calcium mobilization and CCK secretion induced by unsaturated Alds was abolished in the absence of extracellular calcium. In addition, the inhibition of the transient receptor potential ankyrin 1 (TRPA1) channel suppressed unsaturated Ald-induced CCK secretion and intracellular calcium mobilization.
  
  
  CONCLUSIONS
  Unsaturated Alds are potent aliphatic stimulants for CCK secretion through the activation of TRPA1.
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan; Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Nakajima
authors.forename: Tohru
authors.initials: T
authors.lastname: Hira
authors.forename: Asuka
authors.initials: A
authors.lastname: Yahagi
authors.forename: Chigusa
authors.initials: C
authors.lastname: Nishiyama
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Yamashita
authors.forename: Jun
authors.initials: J
authors.lastname: Imagi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hara
mesh_terms: D000447:Aldehydes / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D002766:Cholecystokinin / Q000378:metabolism*; D019858:Enteroendocrine Cells / Q000187:drug effects / Q000378:metabolism; D005227:Fatty Acids / Q000494:pharmacology; D051379:Mice; D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D005227:Fatty Acids; D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels; C475685:Trpa1 protein, mouse; D002766:Cholecystokinin; D002118:Calcium
keywords: Aldehyde; CCK; TRPA1