Exposure to diesel exhaust particles (DEP) is suspected to contribute to @entity2 and @entity66 . In recent years generation of reactive @entity26 species capable of inducing cellular oxidative stress has been in focus as one of the underlying mechanisms behind the genotoxic effects of particles. However, the role of the antioxidative defence system still needs to be clarified, especially in relation to low-dose DEP exposures. The aim of this study was to characterize the effects of short-term exposure to DEP in terms of DNA damage and expression of key response genes towards oxidative stress in lungs of @entity19 . @entity19 were exposed by inhalation to 20 or 80 mg/m3 DEP inhaled as either a single dose, or four lower doses (5 and 20 mg/m3) inhaled on four consecutive days. Our results indicate that @entity10183 mRNA expression in lung tissue was up-regulated after both types of DEP exposures, whereas @entity35308 expression was only up-regulated after repeated exposures. The level of oxidative DNA damage in terms of @entity20821 ( @entity20821 ) was increased in the lung tissue after a single exposure, whereas increased levels of DNA strand breaks was observed in bronchoalveolar lavage cells after repeated DEP exposures. The levels of @entity20821 and @entity35308 mRNA in lung tissue were mirror images. This suggests that after repeated exposures, up-regulation of DNA repair counteracts an increased rate of @entity20821 formation leaving the steady state level of @entity20821 in DNA unchanged. In conclusion, this study indicates that a single high dose of DEP generates @entity20821 in lung tissue, whereas the same dose inhaled as four low-exposures may up-regulate the antioxidative defence system and protect against generation of @entity20821 .

Oxidative DNA damage and defence gene expression in the XXXX lung after short-term exposure to diesel exhaust particles by inhalation.

@entity20821 :: ('MESH:C067134', 'Chemical') :: ["8-oxo-7,8-dihydro-2'-deoxyguanosine", '8-oxodG'] @entity66 :: ('MESH:D004194', 'Disease') :: ['cardiopulmonary diseases'] @entity19 :: ('10090', 'Species') :: ['mice', 'Mice'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity2 :: ('MESH:D008175', 'Disease') :: ['lung cancer'] @entity35308 :: ('18294(Tax:10090)', 'Gene') :: ['OGG1'] @entity10183 :: ('15368(Tax:10090)', 'Gene') :: ['HO-1']
@entity19 :: (10090,Species) :: ['mouse']
