Figure 1. Plaque growth and size are significantly increased in Hp 2-2 mice as determined from in vivo ultrasound measurements and from morphometric measurements of formalin fixed tissue.

A. Measurement of plaque volume. In green is the three dimensional outline of the aortic arch (AA) with its arterial branches (BC-brachiocephalic, CC-common carotid, SC-subclavian). DA-descending aorta. Plaque (arrow) is visualized in blue at the aortic arch-brachiocephalic artery bifurcation.

B. Brachiocephalic plaque volume was assessed in vivo in the same mouse by ultrasound at both 3 and 6 months in Hp 1-1 ApoE^−/− or Hp 2-2 ApoE^−/− mice with or without DM induced at 3 months of age. Plaque volume measurements are shown only for mice in which ultrasound measurements were obtained from the same mouse at both 3 months and 6 months, with N indicating the number of mice in each of the four groups with measurements at both 3 and 6 months. The change in plaque volume was significantly different between the 4 groups (ANOVA p=0.009). Pairwise comparisons for the change in plaque volume demonstrated significant differences (*) in plaque growth between Hp 1-1 and Hp 2-2 mice and between Hp 1-1 DM and Hp 2-2 DM mice (p<0.005 for both comparisons).

C. Brachiocephalic plaque area is significantly increased in Hp 2-2 mice at 6 months of age in paraffin embedded formalin fixed sections. Plaque area was assessed on formalin fixed plaques at 6 months. Plaque area was significantly different between the four groups (p<0.009) (N, number of mice assessed in each group). Pairwise comparisons for the change in plaque volume demonstrated significant differences in plaque growth between Hp 1-1 and Hp 2-2 mice and between Hp 1-1 DM and Hp 2-2 DM mice (p<0.005 for both comparisons). Their was a borderline significant increase in plaque area at 6 months in Hp 2-2 DM compared to Hp 2-2 mice, p=0.075).