Figure 6.

Contribution of LOX to oxidative stress and vascular stiffness in hypertension. (A) The structural and mechanical properties of first-order mesenteric arteries were studied with a pressure myograph (Danish Myo Tech, Aarhus, Denmark) as previously described [78,79]. Stress–strain curves were obtained in arteries from WT and TgLOX^VSMC mice. Vascular stiffness was determined from the stress–strain relationship which is nonlinear; therefore, we obtained the incremental elastic modulus (Einc) by determining the slope of the stress–strain curve of individual animals. Einc values were (mean ± SEM) WT: 4.11 ± 0.12 (n = 6); LOX: 5.17 ± 0.27 (n = 8). *p < 0.05 vs. WT by unpaired student t-test. For simplification, statistical analysis is shown in the stress–strain curves. (B) The elastin organization within the internal elastic lamina was studied in segments of mesenteric arteries from TgLOX^VSMC and WT mice using fluorescence confocal microscopy based on the autofluorescent properties of elastin (ex: 488 nm; em: 500–560 nm), as previously described [78,79]. Serial optical sections from the adventitia to the lumen (z step = 0.5 µm) were captured with a X63 oil objective, by using the 488 nm line of the confocal microscope. (image size 53 × 53 µm). (C) Working model showing that LOX induced-oxidative stress alters elastin structure and promotes vascular stiffness in hypertension.