Local and global mechanical properties of atherosclerotic aorta were measured in 6 Watanabe heritable hyperlipidemic (WHHL) rabbits. Descending thoracic aortas were obtained from animals aged 8 months. Local initial elastic modulus Eiocal and global incremental elastic modulus H θθ were measured with pipette aspiration technique and pressure-diameter tests, respectively. Opening angles were measured as an index of residual strain. Eiocal of atherosclerotic lesion (fatty streak) was 19.1 ±1.9 kPa (mean±SEM), which was significantly smaller than that of preserved area (38.9± 7.5 kPa). Hθθ of the whole specimen was 1 260±140 kpa at 100 mmHg, and was not statistically different from the value measured in age-matched controls, Japanese White rabbits. Opening angle was significantly larger in WHHL rabbits than in their controls. These results suggest that, in the early stages of atherosclerosis, (1) the lesion is more compliant than normal aortic tissues ; ( 2 ) niacroscopic mechanical properties are not sensitive to local mechanical change; (3 ) residual strain increases with the development of the disease. It is important to assess local mechanical properties and residual strain when studying mechanical properties of atherosclerotic aortas.
|ジャーナル||Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A|
|出版ステータス||Published - 1999|
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