Figure 3
Chronic effects in mice treated with varied elastase concentrations. Ultrasound-based 3D segmentations at day 56 compare well with end-of-study histology (MPC shown). (a) In mice treated with heat-inactivated elastase, the aortas showed no degradation of the elastin and remained the same size throughout the study. In contrast, mice treated with (b) 2.5 mg/ml, (c) 5 mg/ml, and (d) 10 mg/ml elastase-treated groups had fragmented elastin and varying-sized aneurysms. In addition, although not all mice in the 5 and 10 mg/ml groups had thrombus, those that did have thrombus tended to have a thin proximal wall and a thrombus-laden distal portion. (e) Diameter measurements indicated a graded effect of elastase concentration, with the 2.5 mg/ml group having moderately-sized aneurysms, and the 5 and 10 mg/ml groups having large aneurysms. (f) Despite differences in diameter, circumferential strain was statistically indistinguishable among elastase-treated groups, and was only different from the heat-inactivated control. (g) MMP activity was also increased in aneurysmal mice, which correlated linearly with diameter (h). Of interest, mice with thrombus tended to have higher MMP activity (not statistically assessed). *p < 0.05; **p < 0.01; ***p < 0.001 with lines indicating the comparison.
