The purpose of this study was to establish experimental arteriosclerosis in rabbit, not by hypercholesterolemia but by normolipidemic method, and further to investigate whether or not sclerotic arteries of rabbits by this method have the same properties in the function (viscoelastic properties) and the structure as human arteries with arteriosclerosis. The materials used consisted of 118 rabbits including 75 sclerotic rabbits and 277 cases dissected. Arteriosclerosis of rabbits were induced by the following two methods, namely injury method using 0.1% epinephrine injection and hypoxic method using pure nitrogen gas inhalation. In each material, basic data such as body weight, length of aorta, diameter and thickness of thoracic aorta were measured and also examined were aortic pulse wave velosity (PWV) showing viscoelastic property of arterial wall and medial elastin content of thoracic aorta as a factor of the structure of arterial wall.
Results
1. In comparison with human aorta, rabbit aorta was relatively longer and slender, and the ratio of the length of abdominal aorta to thoracic aorta was higher than that of human aorta. But the ratio of thickness to diameter was almost same in both materials.
2. In the control group, mean value of PWVs was 7.3m/sec in human and 5.7m/sec in rabbit. PWV of sclerotic group was higher than that of control group and human gave higher values than rabbits.
3. In control group, the mean value of medial elastin content of human thoracic aorta was 34v/v% and the corresponding value of rabbits was 44v/v%. The value was poorer in the sclerotic group than in the control group, and in human than in rabbits.
4. The relationship of PWV—1/Elastin in human and rabbit showed almost the same tendency, as PWV increased along with a decrease of medial elastin content, and so, in the final analysis, we could not distinguish human and rabbit in this respect. Namely, we could say that, from a view point of the function and the structure, both arteries had almost the same character.