title: Chronic pulmonary toxicity study of indium-tin oxide and indium oxide following intratracheal instillations into the lungs of hamsters.
abstract: OBJECTIVE
  The aim of this study was to clarify the chronic toxicological effects of indium-tin oxide (ITO) and indium oxide (In(2)O(3)) on laboratory animals.
  
  
  METHODS
  Male Syrian golden hamsters were intratracheally administered 3 mg/kg or 6 mg/kg of ITO particles, or 2.7 mg/kg or 5.4 mg/kg of In(2)O(3) particles, containing 2.2 mg/kg or 4.5 mg/kg of indium, twice a week, for 8 wk. Control hamsters were given vehicle of distilled water only. The hamsters were euthanized serially up to 78 wk after the final instillation and the toxicological effects were determined.
  
  
  RESULTS
  Body weight gain was significantly suppressed in the ITO 6 mg/kg-treated hamsters compared with the control group, but not in the ITO 3 mg/kg-treated or In(2)O(3)-treated hamsters. Relative lung weights among all the indium-treated groups were significantly increased compared to that in the control group throughout the observation period. The serum indium concentration among all the indium-treated groups gradually increased up to the end of the observation period. Histopathologically, foci of slight to severe pulmonary inflammatory response with diffuse alveolar or bronchiolar cell hyperplasia, expansion of the alveolar spaces and interstitial fibrotic proliferation were present in all the indium-treated hamsters and the severity of these lesions worsened with the passage of time. Lung benign adenomas were only manifest in 3 out of 15 of the ITO 6 mg/kg-treated hamsters.
  
  
  CONCLUSIONS
  The present results clearly demonstrate that ITO and In(2)O(3) particles caused chronic pulmonary toxicity when repeated intratracheal instillations were given to hamsters.
authors: Department of Environmental Medicine, Graduate School of Medical Sciences, Kyushu University, Japan. atanaka@envmed.med.kyushu-u.ac.jp
authors: Akiyo
authors: A
authors: Tanaka
authors: Miyuki
authors: M
authors: Hirata
authors: Toshiaki
authors: T
authors: Homma
authors: Yutaka
authors: Y
authors: Kiyohara
mesh_terms: D000818:Animals; D002908:Chronic Disease; D006224:Cricetinae; D007204:Indium / Q000008:administration & dosage / Q000633:toxicity*; D007322:Instillation, Drug; D007442:Intubation, Intratracheal; D008297:Male; D008647:Mesocricetus; D011014:Pneumonia / Q000139:chemically induced*; D017971:Tin Compounds / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D017971:Tin Compounds; D007204:Indium; C047711:indium oxide; C109984:indium tin oxide