1. MWCNT-7 administered to the lung by intratracheal instillation induces development of pleural mesothelioma in F344 rats.
- Author
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Numano T, Higuchi H, Alexander DB, Alexander WT, Abdelgied M, El-Gazzar AM, Saleh D, Takase H, Hirose A, Naiki-Ito A, Suzuki S, Takahashi S, and Tsuda H
- Subjects
- Animals, Asbestos, Crocidolite adverse effects, Injections, Intraperitoneal methods, Lung Neoplasms pathology, Male, Mesothelioma pathology, Mesothelioma, Malignant, Pleural Neoplasms pathology, Rats, Rats, Inbred F344, Trachea drug effects, Trachea pathology, Lung drug effects, Lung Neoplasms chemically induced, Mesothelioma chemically induced, Nanotubes, Carbon adverse effects, Pleural Neoplasms chemically induced
- Abstract
Multi-walled carbon nanotube-7 (MWCNT-7) fibers are biopersistent and have a structure similar to asbestos. MWCNT-7 has been shown to induce malignant mesothelioma when administered by intrascrotal or intraperitoneal injection in rats and mice, and an inhalation study demonstrated that rats exposed to respirable MWCNT-7 developed lung tumors. MWCNT-N, which is similar to MWCNT-7, was shown to induce both lung tumors and malignant mesothelioma in rats when administered by trans-tracheal intrapulmonary spraying (TIPS). The present study was performed to investigate the carcinogenicity of MWCNT-7 when administered by the TIPS method. Ten-week-old male F344/Crj rats were divided into 3 groups and administered 0.5 mL vehicle, 0.250 μg/mL MWCNT-7 or 0.250 μg/mL crocidolite once a week for 12 weeks (total doses of 1.5 mg/rat) and then observed for up to 104 weeks. Rats in the MWCNT-7 group began to die from pathologies associated with the development of malignant mesothelioma 35 weeks after the final TIPS administration. Overall, the incidence of malignant mesothelioma in the MWCNT-7 group was significantly higher than in the vehicle or crocidolite groups., (© 2019 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)
- Published
- 2019
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