Nitrogen dioxide inhalation induces genotoxicity in rats

Nitrogen dioxide (NO2) is a ubiquitous reactive free-radical gas, which has been associated with momentary and chronic health effects. In the present study, comet, micronucleus (MN) and DNA-protein crosslinks (DPC) assays were used to investigate the genotoxicity following in vivo inhalation exposure of rats to NO2. The results show that inhalation exposure of rats to NO2 induced DNA strand breakage and the formation of DPC in the cells from various internal organs (brain, lung, liver, spleen, kidney and heart), as well as resulted in obvious increase of MN frequency in the bone marrow cells of rats. Furthermore, above genotoxic responses showed significant linear dose-dependent manners. These results implicate that NO2 is a genotoxic agent and these observations are informative for understanding the mechanisms of adverse effects of nitrogen dioxide. (c) 2012 Elsevier Ltd. All rights reserved.