Oxidative stress and DNA damage responses in rat and mouse lung to inhaled carbon nanoparticles

Abstract

We have investigated whether short-term nose-only inhalation exposure to electric spark discharge-generated carbon nanoparticles (∼60 nm) causes oxidative stress and DNA damage responses in the lungs of rats (152 μg/m³; 4 h) and mice (142 μg/m³; 4 h, or three times 4 h). In both species, no pulmonary inflammation and toxicity were detected by bronchoalveolar lavage or mRNA expression analyses. Oxidative DNA damage (measured by fpg-comet assay), was also not increased in mouse whole lung tissue or isolated lung epithelial cells from rat. In addition, the mRNA expressions of the DNA base excision repair genes OGG1, DNA Polβ and XRCC1 were not altered. However, in the lung epithelial cells isolated from the nanoparticle-exposed rats a small but significant increase in APE-1 mRNA expression was measured. Thus, short-term inhalation of carbon nanoparticles under the applied exposure regimen, does not cause oxidative stress and DNA damage in the lungs of healthy mice and rats.

Keywords::

• Nanoparticles
• inhalation
• oxidative stress
• DNA damage
• rodent

Acknowledgments

We thank Wolfgang Kreyling from the Institut of Lung Biology and Disease at the Helmholtz Center Munich-Research Center for Environmental Health, for providing the Palas Soot Generator. We also thank Irmgard Förster from the Molecular Immunology group and the technical staff from the IUF animal facility for their support as well as John Boere and Paul Fokkens from the RIVM for their experimental assistance.

Declaration of interest: This study was supported by grants from the German Federal Ministry of Environment (BMU), and the Dutch Ministry of Housing, Spatial planning and the Environment (VROM). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.