Histopathological Changes in Rat Lung Following Intratracheal Instillation of Silicon Carbide Whiskers and Potassium Octatitanate Whiskers
Source: Inhalation Toxicology, Volume 19, Number 9, July 2007 , pp. 753-758(6)
Publisher: Informa Healthcare
Abstract:We evaluated the pattern of pulmonary inflammation for the assessment of the biological hazards of two man-made mineral fibers. Rats were exposed by intratracheal instillation to a 2 mg dose of each of two kinds of man-made mineral fibers (PT1, potassium octatitanate whisker; and SiCW, silicon carbide whisker), or three kinds of comparable respirable particles (crystalline silica, crocidolite asbestos, and titanium dioxide, TiO2). The lung tissue was evaluated at 3 day, 1 wk, and 1, 3 and 6 mo after exposure. Digital images taken of the lung sections were examined by morphometric point counting method (PCM). PT1 and SiCW showed a similar inflammatory pattern, which contains temporal inflammation such as moderate alveolitis within 1 wk after the exposure, and in later phase aggregation foci of instilled fibers. Differences in repair patterns of these two man-made mineral fibers showed that the toxicity of these two fibers is less toxic than for crocidolite or crystalline silica. Although SiCW showed a higher inflammation score than TiO2 within 1 mo after instillation, the inflammation scores and fibrotic changes of PT1 and SiCW were not significant as TiO2 at 3 mo and 6 mo in this study. Careful use should be recommended when these materials are used in the workplace.
Document Type: Research Article
Affiliations: 1: Department of Occupational Pneumology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Yahatanishi-ku, Kitayushu, Japan 2: Department of Environmental Health Engineering, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Yahatanishi-ku, Kitayushu, Japan
Publication date: 2007-07-01