Abstract: Objective To analyze the effect of local unstable atherosclerotic plaque on plaque formation in the carotid and aortic arteries of rabbits. Methods Thirty New Zealand white rabbits were randomly divided into atherosclerosis model group, high-fat diet feeding group, and normal chow feeding group (blank control group). In the model group, carotid artery balloon injury was induced after 4 weeks of high-fat diet feeding. Eight weeks later, all the rabbits were euthanized for histopathological examination of the carotid artery and abdominal aorta, and the mean intimal thickness and plaque to lumen area ratio were measured using image analysis software. Venous blood samples were collected from the rabbits for blood lipid analysis. Result At the ends of 4, 8 and 12 weeks, the rabbits in the model group and high-fat feeding group, but not those in the blank control group, all showed significant weight gain compared with their body weight at 0 week (P<0.05). The mean intimal thickness was significantly greater in atherosclerosis model group than in the other two groups (P<0.05). In atherosclerosis model group, the mean intimal thickness and plaque to lumen area ratio in the injured carotid artery were significantly greater than those in the contralateral carotid artery and abdominal aorta (P<0.05). At the end of the 12 weeks, the levels of triglyceride (TG), total cholesterol (TC), low-density cholesterol (LDL-C), high-density cholesterol (HDL-C) and high-sensitivity C- reactive protein (CRP) were all significantly higher in the model group and high- fat feeding group than in the blank control group (P<0.05); the levels of TG, TC, LDL-C, or HDL-C did not differ significantly between the model group and high- fat feeding group (P>0.05), but the level of CRP was significantly higher in arteriosclerosis model group (P<0.05). Conclusion Local unstable atherosclerotic plaque can increase the level of CRP and promote the formation of atherosclerotic plaques in the carotid artery and abdominal aorta in rabbits.

Key words: atherosclerosis; unstable plaques; peripheral arteries