title: Accumulation of element Ti in macrophage-like RAW264 cells cultured in medium with 1 ppm Ti and effects on cell viability, SOD production and TNF-alpha secretion.
abstract: The adverse effect of Ti on body-defense macrophage is not well understood. The aims of this study were twofold: (1) to examine the intracellular accumulation of Ti element; and (2) to measure the cell viability, superoxide dismutase (SOD) production, and TNF-alpha secretion of macrophage-like RAW264 cells cultured for two days in medium with 1 ppm Ti prepared from acidic ICP Ti standard solution. PIXE analysis showed that element Ti was accumulated up to 7.3 ppm in RAW264 cells when cultured in the medium with 1 ppm Ti. Further, RAW264 cells cultured in the medium with 1 ppm Ti exhibited cell viability of about 60%, SOD production of about 180%, and TNF-alpha secretion of about 170% relative to those of control cells cultured in the medium without Ti. It was speculated that phagocytosis of minute Ti-containing complex (mostly TiO2) by macrophage caused oxidative stress and inflammatory reaction, leading to cell proliferation arrest and increased production of SOD and TNF-alpha.
authors.affiliation: Dept. of Dental Materials Science and Technology, Iwate Medical University School of Dentistry, 1-3-27 Chuo-dori, Morioka, Iwate 020-8505, Japan. mtaira@iwate-med.ac.jp
authors.forename: Masayuki
authors.initials: M
authors.lastname: Taira
authors.forename: Kaori
authors.initials: K
authors.lastname: Sasaki
authors.forename: Setsuo
authors.initials: S
authors.lastname: Saitoh
authors.forename: Takashi
authors.initials: T
authors.lastname: Nezu
authors.forename: Minoru
authors.initials: M
authors.lastname: Sasaki
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Kimura
authors.forename: Kazunori
authors.initials: K
authors.lastname: Terasaki
authors.forename: Kouichiro
authors.initials: K
authors.lastname: Sera
authors.forename: Takayuki
authors.initials: T
authors.lastname: Narushima
authors.forename: Yoshima
authors.initials: Y
authors.lastname: Araki
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D017077:Culture Media, Conditioned; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D018384:Oxidative Stress; D013052:Spectrometry, X-Ray Emission; D013482:Superoxide Dismutase / Q000096:biosynthesis*; D014025:Titanium / Q000032:analysis / Q000633:toxicity*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D017077:Culture Media, Conditioned; D014409:Tumor Necrosis Factor-alpha; D014025:Titanium; D013482:Superoxide Dismutase