title: Effect of titanium dioxide on the oxidative metabolism of alveolar macrophages: an experimental study in rats.
abstract: Metallic implants of titanium are used therapeutically in biomedicine because of its excellent biocompatibility. However, no metal or alloy is completely inert. We have previously shown that titanium oxide (TiO(2)) is transported in blood by phagocytic monocytes and deposited in organs such as liver, spleen, and lung 6 months after intraperitoneal injection (ip). Furthermore, it is well known that exposure to metal traces alters the cellular redox status. Thus, the aim of the present study was to determine the presence of titanium in target organs after chronic exposure, assess the potential structural alterations, and evaluate the oxidative metabolism of alveolar macrophages (AM) in the lung. Rats were ip injected with 1.60 g/100 g body wt of TiO(2) in saline solution. Organs (liver, spleen, lung) were processed for histological evaluation. Reactive oxygen species (ROS) in AM obtained by bronchoalveolar lavage (BAL) were evaluated using the nitroblue tetrazolium test and quantitative evaluation by digital image analysis. The histological analysis of organs revealed the presence of titanium in the parenchyma of these organs with no associated tissue damage. Although in lung alveolar macrophages TiO(2) induced a significant rise in ROS generation, it failed to cause tissue alteration. This finding may be attributed to an adaptive response.
authors.affiliation: Department of Oral Pathology, School of Dentistry, University of Buenos Aires, Buenos Aires, Argentina. dolmedo@argentina.com
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Olmedo
authors.forename: Deborah R
authors.initials: DR
authors.lastname: Tasat
authors.forename: María B
authors.initials: MB
authors.lastname: Guglielmotti
authors.forename: Rómulo L
authors.initials: RL
authors.lastname: Cabrini
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002470:Cell Survival / Q000187:drug effects; D008168:Lung / Q000166:cytology / Q000187:drug effects; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010084:Oxidation-Reduction / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000494:pharmacology*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium