[Analysis on mechanical properties of aortic artery in rats with atherosclerosis]

To understand the mechanical properties of aortic artery of atheroselerosis (AS), the aortic artery of rat with AS was studied by mechanical test. Wistar rats were used for establishing the model. The mechanical measurements of opening angle in zero-stress state and the vessel loading test were conducted on the isolated aortic arteries of AS rats. Data on the stress-strain of aortic artery were obtained. Determination of percentage of collagen content was made with the use of electron microscope. The relationship between mechanical measurements and collagen concentration was evaluated. The opening angle in the group of AS was significantly smaller than that in control (87.74 degrees +/-9.67 degrees vs. 196.03 degrees +/- 27.76 degrees, P < 0.001). Significant decrease of material constants (alpha0, alpha1, alpha2, b0, b1, b2) in both long axis and radial axis was observed in AS group(campared with control, P < 0.05-0.001). Close relationship between the mechanical constants and the percentage of elastin and collagen content was observed (r = -0.7523 to -0.8423, P < 0.001). In conclusion, mechanical remodeling in aortic artery of AS might be related with histological remodeling.