title: Effect of different magnitudes of tension force on prostaglandin E2 production by human periodontal ligament cells.
abstract: Periodontal ligament (PDL) cells are known to produce prostaglandin E2 (PGE2) in response to mechanical stress. However, the rate of PGE2 production from PDL cells in response to different magnitudes of tension forces has not been examined. This study, therefore, was undertaken to determine the effect of different magnitudes of tension forces on PGE2 production and inositol trisphosphate (IP3) levels in PDL cells in vitro. Human PDL cells were cultured on flexible-bottomed plates and placed on a Flexercell strain unit. Cells were flexed at six cycles (5-s strain, 5-s relaxation) at six steps of tension force (9, 12, 15, 18, 21, 24% increase in surface area) for 5 days. PGE2 production and IP3 levels were determined by radioimmunoassay. There was a 6- and 25-fold increase in the rate of PGE2 production by cells exposed to low (9%) and high (24%) tension forces, respectively, and these increases were tension force-dependent. Tension force also induced increases in the intracellular levels of IP3 that did not seem to be directly related to the production of PGE2. The different rates of PGE2 production by PDL cells in response to different magnitudes of mechanical stress may be of importance in PDL and alveolar bone metabolism.
authors.affiliation: Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: N
authors.initials: N
authors.lastname: Shimizu
authors.forename: T
authors.initials: T
authors.lastname: Goseki
authors.forename: Y
authors.initials: Y
authors.lastname: Shibata
authors.forename: H
authors.initials: H
authors.lastname: Takiguchi
authors.forename: T
authors.initials: T
authors.lastname: Iwasawa
authors.forename: Y
authors.initials: Y
authors.lastname: Abiko
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002455:Cell Division; D002478:Cells, Cultured; D002648:Child; D015232:Dinoprostone / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007295:Inositol Phosphates / Q000032:analysis / Q000096:biosynthesis; D008297:Male; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D007295:Inositol Phosphates; D010716:Phosphatidylinositols; D015232:Dinoprostone; D007213:Indomethacin