实验性兔主动脉粥样硬化易损斑块模型的建立与评价

目的探索建立实验性兔主动脉粥样硬化易损斑块模型的新方法。方法24只雄性日本大耳白家兔随机分为对照组8只,实验组16只,对照组给予普通饲料;实验组给予高胆固醇饲料、注射牛血清白蛋白及进行腹主动脉球囊拉伤术,分别于0周、3周、6周、10周检测血脂、ox-LDL、TNF-α、IL-1、IL-10,实验结束时取腹主动脉进行病理形态学分析及NF-κBp65亚基免疫组化染色分析。结果实验组斑块内膜面积比为53.6%,脂核面积与斑块面积比为54.9%,斑块纤维帽厚度与内膜中膜厚度（IMT）比约为8.5%;除甘油三酯变化不大外,实验组TC、LDL-C、HDL-C、LDL-C/HDL-C、TC/HDL-C、ox-LDL、TNF-α、IL-1、IL-10均有明显升高趋势,在3周、6周、10周时与对照组比较差异有统计学意义;且NF-κBp65亚基阳性染色面积较对照组高13.5倍。结论高脂喂养、免疫损伤加球囊拉伤可以成功建立家兔主动脉粥样硬化易损斑块模型。

Establishment and Evaluation of a Rabbit Model of Aortic Vulnerable Atherosclerotic Plaque

Background It was the leading pathological foundation of acute coronary syndrome （ACS） that stable atherosclerotic（AS） plaque develops into vulnerable plaque （VP） and then accompanied by thrombosis. Recently,the research of VP has become a hotspot in cardiovascular disease studies, and the animal model of vulnerable plaque is a critical problem. Therefore, it＇s important to establish an ideal animal model of VP. Various factors are believed to be related to the development of VP, such as mechanical forces, blood lipid and active inflammation, etc. In the past years, many scholars at home and abroad had done their best on the problem, such as the ApoE deficient mice model, gene transfection rabbit model, etc. However, a recognized and reliable VP model hadn＇t taken shape so far. It was reported that hypercholesterolemia and acute immune injury promoted the formation of early atherosclerosis lesions cooperatively. Objective This study intended to explore a method of establishing an aorta vulnerable plaque model in rabbits, similar to that in human body, and its characterization. Methods Twenty-four male Japanese white rabbits aged 2 months with body weight of 2.0± 0.2 kg were purchased from Bei Jin Vital River Laboratory Animal Technology Co., Ltd. All the rabbits were fed for 1 week and then divided into two groups： the control group （8 animals） and the experimental group （16 animals）. Rabbits in the control groups were given normal feed, while rabbits in the experimental group were given a diet containing 1% cholesterol 100 g/d （including 1% cholesterol,5% lard,5% egg yolk and 89% normal feed） from the first week to the tenth week,and injected bovine serum albumin （BSA） 250 mg/kg once via the ear marginal vein at the second week, and then underwent balloon-induced aortic wall injury via the femoral artery at the fourth week. All the rabbits drink water freely. Total cholesterol （ TC ）, triglyceride （ TG）, low-density lipoprotein cholesterol （ LDL-C ）, high-density lipoprotein cholesterol （ HDL-C）, oxidized low density lipoprotein （ ox-LDL）, tumor necrosis factor-α （ TNF-α ）, interleukin-1 （ IL-1 ） and interleukin IO （IL-IO） were tested at 0, 3rd, 6th and 10th week. Histopathological examination and NF-κBp65 subunit immunohistochemical analysis of the aorta were performed at the end of the experiment. The ratio of area of plaqne/intima （PA/ IA）, ratio of area of lipid core/plaque （LCA/PA）, ratio of thickness of fibrous cap/intima-media （FCT/IMT） and the ratio of NF-κB p65 subunit positive area were assessed and calculated by a 2000-high-definition colorful pathological image analysis system. Results 8 rabbits died during the experiment in all, including 2 rabbits in the control group and 6 rabbits in the experimental group. The body weight of the two groups showed an upward trend over time. However, there was no statistically significant difference between the two groups （P 〉 0.05）. Serum TC,LDL-C, HDL-C,TC/HDL-C, LDL-C/HDL-C in the experimental group showed an upward trend over time except TG, and there was a significant difference in comparison with those in the control group at 3,6 and 10 weeks （P 〈 0.01 ）. At the end of experiment, serum TC and LDL-C reached （24.043 ± 4. 725） mmol/L and （11.730 ±3.090） mmol/L,respectively. Serum ox-LDL in the experimental group was 8 times higher than that in the control group at lOth week. Moreover, TNF-α, IL-I, IL-10 at 10th week were 3.4,4,4.7 times higher, respectively, than those at 0 week in the experimental group, and the ascending IL-10 did not show the same extent as TNF-a, IL-1 at 3rd week. In the experimental group, PA/IA was （53.6 ± 10.5） %, LCA/PA was （54.9 ±9.4） %, FCT/IMT was （8.5 ±4.2） %, and the ratio of NF-tcBp65 subunit positive area was （16.2 ±4.6）%, which was 13.5 times higher than that in the control group. Conclusions A rabbit model of aortic vulnerable atherosclerotic plaque has been successfully established by combination of high cholesterol diet, bovine serum albumin injection and balloon injury. This model showing typical hyperlipemia, active inflammation in the atherosclerotic plaque area,and similar morphological changes to those in human vulnerable plaque, may serve as an useful tool in research on atherosclerosis.