Effect of a Chronic Cholesterol-rich Diet on Vascular Structure and Oxidative Stress in LDLR-/- Mice
Aims: There is conflicting evidence regarding the relationship between hypercholesterolemia and oxidative stress in vessels. To test the potential relationship, a mouse model of hypercholesterolemia was used. Methods: Low density lipoprotein receptor-deficient (LDLR-/-) and control (C57Bl/6) mice were fed a normal or (1.25%) high-cholesterol (HC) diet for 8 weeks, and the incidence of this chronic diet was evaluated on the degree of vascular oxidative stress and vascular structure (collagen content and lipid infiltration expressed in arbitrary units: AU=%/mm2). Results: Animals treated with the HC diet presented an increase in lipid infiltration (0.35±0.13 vs. 1.7±0.18 control and 1.04±0.16 vs. 1.84±0.23 LDLR-/-, AU p<0.05) associated with higher collagen content (control: 2.13±0.40 vs. 3.46±0.36 and LDLR-/-: 2.37±0.36 vs. 3.79±0.60; AU p<0.05 red Sirius staining). Interestingly, ROS production in the aorta was only increased in the LDLR-/- +cholesterol group (0.17±0.04 and 0.16±0.05 in the control groups, 0.14±0.02 vs. 0.34±0.06 in the LDLR-/- groups, p<0.05). C57Bl/6 and LDLR-/- mice presented altered vascular structure associated with the rich cholesterol diet, which was not necessarily associated with increased oxidative stress. Conclusion: These findings highlight the complex interrelation between oxidative stress and lipid metabolism in the circulatory tract.