HSP 70 overexpression in vulnerable plaques of abdominal aorta in model rabbits.

Objective To investigate HSP70 expression in vulnerable plaques in abdominal aorta the role of pravastation on its overexpression in model rabbits.Methods The atherosclerotic plaques were made in 30 rabbits by undergoing balloon-induced abdominal aorta wall injury and then being fed on a diet of high cholesterol.Then 30 rabbits were divided into three groups randomly: one group were fed on a diet of high cholesterol(group C),and another were fed on Pravastatin besides cholesterol(group P1).The third were fed on a diet of high cholesterol in first two months,and Pravastatin was added to the diet in second two months.The intima-media thickness(IMT) and the atherosclerotic plaques were measured with ultrasound imaging before a diet of high cholesterol and half one month、one month、two months、three months and four months after abdominal aorta wall injuried.All rabbits were killed after 4 months,then vulnerable plaques were taken out,and overexpression of HSP70 was detected with SP immunohistochemical technique.Results IMT became thicker and thicker with time after the high cholesterol diet.The IMT of group P was significantly less than that of C group after 4 month post-injury(P0.01).Vulnerable plaques were main from both C and group P2.In group C,HSP70 overexpression cells were mainly focused on shoulder and fibrous cap regions(P0.01,P0.01);while in group P2 they were mainly focused on shoulder region(P0.01),and the positive rate of HSP70 overexpression cells in fibrous cap in group P2 was significantly less than that of group C(P0.01).Conclusions There exists HSP70 overexpression in vnlnerable plaques of abdominal aorla,which can be decreased by pravastatin intervention.