title: Lysophosphatidic acid, a growth factor-like lipid, in the saliva.
abstract: Lysophosphatidic acid is a multifunctional phospholipid mediator and elicits a variety of biological responses in vitro and in vivo. Evidence is accumulating that lysophosphatidic acid plays important physiological roles in diverse mammalian tissues and cells. In the present study, we first examined whether lysophosphatidic acid is present in human saliva. We found that a significant amount of lysophosphatidic acid is present in the saliva (0.785 nmol/ml). The predominant fatty acyl moiety of lysophosphatidic acid was 18:1n-9 + n-7 followed by 18:0 and 16:0. A small amount of lysoplasmanic acid, an alkyl ether-linked analog of lysophosphatidic acid, was also detected in the saliva (0.104 nmol/ml). We found that physiologically relevant concentrations of lysophosphatidic acid induced accelerated growth of cells of mouth, pharynx, and esophagus origin in vitro. Lysophosphatidic acid also induced rapid increases in the intracellular free Ca2+ concentrations in these cells. We obtained evidence that lysophosphatidic acid receptor mRNAs are actually present in these cells. These results strongly suggest that lysophosphatidic acid is involved in wound healing in the upper digestive organs such as the mouth, pharynx, and esophagus.
authors.affiliation: Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa 199-0195, Japan. Sugiurat@pharm.teikyo-u.ac.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sugiura
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakane
authors.forename: Seishi
authors.initials: S
authors.lastname: Kishimoto
authors.forename: Keizo
authors.initials: K
authors.lastname: Waku
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: Akira
authors.initials: A
authors.lastname: Tokumura
mesh_terms: D002118:Calcium / Q000378:metabolism; D004848:Epithelium / Q000254:growth & development / Q000378:metabolism; D004947:Esophagus / Q000254:growth & development / Q000378:metabolism; D006801:Humans; D008246:Lysophospholipids / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D012463:Saliva / Q000737:chemistry / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D008246:Lysophospholipids; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D002118:Calcium