Figure 1. Benzo(a)pyrene (BaP) enhances atherosclerotic plaques in animals fed an atherogenic diet. Microscopic cross-sections (10 µm) of the aortic root were stained with Oil Red O (ORO) (counterstained with hematoxylin) to reveal lipid deposition. Lipid deposition was identified by its red color. B-E, black arrows indicate fatty streak; F-G, foam cells in the aortic root (green arrow), free lipid droplets in variable sizes (black arrow), intact fibrous cap (yellow arrow), calcification (white arrow), and necrotic core (blue arrow). Scale bar, 100 µm, Original magnification, 40x. H, The ORO positive area among different groups (Kruskal Wallis test, P-value = 0.007) was measured in square micrometers. Different superscript letters (a, b, c, etc.) indicate statistically significant differences at a P-value < 0.05 between the groups. Values represent the average of 3 mice. Error bars indicate S.E. A, control; B, atherogenic diet (AtD); C, 1B (1mg/kg BaP); D, 1BA (AtD + 1mg/kg BaP); E, 5B (5mg/kg BaP); F and G, 5BA (AtD + 5mg/kg BaP).