Figure 2

Instillation of DEP increases atherosclerosis. (a) Representative images showing lipid-rich lesions in the aorta following staining with Sudan IV (red stain; orange is non-specific staining). Scale bars = 1 mm. (b) Percentage of the intimal surface staining positive for lipids. Mean ± S.E.M. (n = 3-4 for C57bl6, n = 6-7 for ApoE^−/−), ^* P < 0.05, Mann–Whitney test, saline vs DEP in ApoE^−/− mice. (c) Representative transverse sections of atherosclerotic plaques in the brachiocephalic artery stained with United States Trichrome (UST). Scale bars = 100 μm. (d) Plaque size, as a percentage of medial area was increased in DEP-treated ApoE^−/− mice. Mean ± S.E.M. (n = 3-5 for C57bl6, n = 7-9 for ApoE^−/−), ^* P < 0.05, unpaired t-test, saline vs DEP in ApoE^−/− mice. Mean value obtained from analysis of serial sections at 100 μm intervals for each animal; Mean number of sections per group = 4.4 ± 0.6 for ApoE-saline (n = 9), 4.4 ± 0.8 for ApoE-DEP (n = 7). ApoE^−/− were fed Western diet for 8 weeks, whereas wild-type mice were fed normal chow. (e) Plaque size in the brachiocephalic artery correlated with the extent of pulmonary inflammation (BALF total cell count) at time of necropsy (R² = 0.45, P = 0.0043, n = 16).