Plaque area in whole aorta from 20-21 weeks old ApoE-/-
mice on a regular diet and exposed to control solution (90% saline and 10% BAL fluid) or nTiO
. The plaque areas were determined in the mice after an exposure period of nTiO2 (20.6 nm) or control solution once a week by intratracheal instillation for four weeks, followed by a period of five weeks without exposure to particles. The data are expressed as means ± SEM (n = 8). We could not detect plaques in two mice from each group and these are not shown in the figure. * denotes a significant effect on plaque progression in exposed mice vs. the control group.