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J Occup Health year 2006 volume 48 number 2 page 124 - 128
Classification Original
Title Expression of Heme Oxygenase-1 in the Lungs of Rats Exposed to Crystalline Silica
Author Hiroko NAGATOMO, Yasuo MORIMOTO, Takako OYABU, Masami HIROHASHI, Akira OGAMI, Hiroshi YAMATO, Kaori KURODA, Toshiaki HIGASHI and Isamu TANAKA
Organization Department of Occupational Pneumology, Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health, Japan
Keywords Crystalline silica, Heme oxygenase-1, Oxidative stress, Pulmonary fibrosis
Correspondence H. Nagatomo, Department of Occupational Pneumology, Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan
(e-mail: nhiroko@med.uoeh-u.ac.jp)
Abstract Expression of Heme Oxygenase-1 in the Lungs of Rats Exposed to Crystalline Silica: Hiroko NAGATOMO, et al. Department of Occupational Pneumology, Institute of Industrial and Ecological Sciences, University of Occupational and Environmental Health-Oxidative stress is thought to be the pathogenesis of pulmonary fibrosis induced by particles, and heme oxygenase-1 (HO-1) protects lung tissue against oxidative stress. We hypothesized that HO-1 is also associated with oxidative lung injury caused by exposure to particles. The present study was conducted to investigate the time course of HO-1 expression of lungs exposed to crystalline silica in vivo. Male Wistar rats were administered 1 mg or 2 mg of crystalline silica suspended in saline by a single intratracheal instillation and were sacrificed at 3 d, 1 wk, 1 month, 3 months and 6 months of recovery time. The expression of HO-1 was observed by western blot analysis and immunostaining. Protein levels of HO-1 were increased compared to the controls at 3 d, and from 1 month to 6 months following intratracheal instillation of 2 mg of crystalline silica. The levels of HO-1 were increased compared to the controls from 1 month to 6 months following intratracheal instillation of 1 mg of crystalline silica. Many HO-1 positive cells were found particularly in the alveolar macrophages during immunostaining. These findings suggest that HO-1 is related to lung injury arising from exposure to crystalline silica.