title: Expression of heme oxygenase-1 in the lungs of rats exposed to potassium octatitanate whiskers.
abstract: OBJECTIVE
  Oxidative stress is thought to be the pathogenesis of pulmonary fibrosis induced by asbestos, 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 potassium octatitanate whiskers (PT1), which is one of the asbestos substitutes.
  
  
  METHODS
  Male Wistar rats were administered 1 mg or 2 mg PT1 suspended in saline by a single intratracheal instillation and were sacrificed after recovery for 3 days, 1 wk, 1 mo, 3 mo or 6 mo. Gene expression of HO-1 protein and mRNA and immunostaining were investigated in rat lungs.
  
  
  RESULTS
  HO-1 protein expression was increased from 3 days to 1 mo and at 6 mo in the 1 or 2 mg PT1-exposed groups, and the gene expression of HO-1 mRNA was also increased at 3 days and from 1 mo to 6 mo. HO-1-positive cells were mainly found in the alveolar macrophages and the bronchial epithelial cells in immunostaining.
  
  
  CONCLUSIONS
  These findings suggest that HO-1 is involved in lung damage caused by PT1.
authors.affiliation: Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan. obatasan@med.uoeh-u.ac.jp
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Obata
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Masami
authors.initials: M
authors.lastname: Hirohashi
authors.forename: Akira
authors.initials: A
authors.lastname: Ogami
authors.forename: Takako
authors.initials: T
authors.lastname: Oyabu
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Myojo
authors.forename: Shoko
authors.initials: S
authors.lastname: Kawanami
authors.forename: Seichi
authors.initials: S
authors.lastname: Horie
authors.forename: Hiroko
authors.initials: H
authors.lastname: Nagatomo
authors.forename: Masahiro
authors.initials: M
authors.lastname: Murakami
authors.forename: Isamu
authors.initials: I
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D004847:Epithelial Cells / Q000378:metabolism; D015870:Gene Expression; D051547:Heme Oxygenase-1 / Q000235:genetics* / Q000378:metabolism*; D008168:Lung / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D016676:Macrophages, Alveolar / Q000378:metabolism; D008297:Male; D019016:Mineral Fibers; D018384:Oxidative Stress; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014025:Titanium / Q000633:toxicity*
chemical_list: D019016:Mineral Fibers; D012333:RNA, Messenger; C021028:potassium octatitanate; D014025:Titanium; D051547:Heme Oxygenase-1