title: Pulmonary toxicity of well-dispersed multi-wall carbon nanotubes following inhalation and intratracheal instillation.
abstract: Multi-walled carbon nanotubes (MWCNTs), dispersed in suspensions consisting mainly of individual tubes, were used for intratracheal instillation and inhalation studies. Rats intratracheally received a dose of 0.2 mg, or 1 mg of MWCNTs and were sacrificed from 3 days to 6 months. MWCNTs induced a pulmonary inflammation, as evidenced by a transient neutrophil response in the low-dose groups, and presence of small granulomatous lesion and persistent neutrophil infiltration in the high-dose groups. In the inhalation study, rats were exposed to 0.37 mg/m(3) aerosols of well-dispersed MWCNTs (>70% of MWCNTs were individual fibers) for 4 weeks, and were sacrificed at 3 days, 1 month, and 3 months after the end of exposure. The inhalation exposures delivered less amounts of MWCNTs into the lungs, and therefore less pulmonary inflammation responses was observed, as compared to intratracheal instillation. The results of our study show that well-dispersed MWCNT can produce pulmonary lesions, including inflammation.
authors.affiliation: Institute of Industrial Ecological Sciences, School of Medicine, University of Occupational and Environment Health, Japan. yasuom@med.uoeh-u.ac.jp
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: Motoi
authors.initials: M
authors.lastname: Todoroki
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Hashiba
authors.forename: Yohei
authors.initials: Y
authors.lastname: Mizuguchi
authors.forename: Byeong Woo
authors.initials: BW
authors.lastname: Lee
authors.forename: Etsushi
authors.initials: E
authors.lastname: Kuroda
authors.forename: Manabu
authors.initials: M
authors.lastname: Shimada
authors.forename: Wei-Ning
authors.initials: WN
authors.lastname: Wang
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Fujita
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Endoh
authors.forename: Kunio
authors.initials: K
authors.lastname: Uchida
authors.forename: Norihiro
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Kohei
authors.initials: K
authors.lastname: Mizuno
authors.forename: Masaharu
authors.initials: M
authors.lastname: Inada
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tao
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nakazato
authors.forename: Junko
authors.initials: J
authors.lastname: Nakanishi
authors.forename: Isamu
authors.initials: I
authors.lastname: Tanaka
mesh_terms: D000280:Administration, Inhalation; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D019743:Chemokines, CXC / Q000032:analysis / Q000378:metabolism; D008168:Lung / Q000737:chemistry / Q000187:drug effects* / Q000473:pathology; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000473:pathology; D008297:Male; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity*; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D018675:Toxicity Tests
chemical_list: D019743:Chemokines, CXC; D037742:Nanotubes, Carbon; D009195:Peroxidase; D000469:Alkaline Phosphatase