液氮冻伤术建立动脉粥样硬化破裂斑块及血栓模型

Establishing an Animal Model of Atherosclerotic Plaque Rupture and Thrombosis by Liquid Nitrogen

目的创建一种操作简单、经济实用的动脉粥样硬化(AS)破裂斑块及血栓动物模型。方法21只雄性纯种新西兰白兔随机分为两组:液氮冻伤+高脂喂养组(A组=11只)和高脂喂养组(B组=10只)。A组实施右颈总动脉内膜液氮冻伤术结合高脂饲料喂养,B组单纯给予高脂饲料喂养。8周末以液氮激发斑块破裂,激发前后分别采血检测血脂、hsC-RP、MMP-9及PAI-1水平;激发48 h后处死所有动物,取出右颈总动脉作HE染色及免疫组化染色等,光镜及电镜观察破裂斑块及血栓形成情况。结果8周后兔血脂水平明显升高;激发后血浆hsC-RP、MMP-9及PAI-1均明显升高;所有A组兔子的右颈总动脉均可见AS破裂斑块及血栓形成,而B组兔子未见斑块或血栓形成;所建立的破裂斑块在组织结构、细胞构成、生长特征和脂质沉积方面与人类斑块相似。结论液氮冻伤术能简便、快速、高效地建立AS破裂斑块及血栓模型,从而为研究人类AS破裂斑块及血栓形成的机理和药物干预治疗提供了一种新型动物模型。

Objective To establish a simple, economical, practical animal model of atherosclerotic plaque rupture and thrombosis suitable for the study of human atherosclerosis. Methods 21 healthy male New Zealand white rabbits were randomly divided into two groups： group A（n = 11） and group B（n = 10）. Rabbits in group A underwent cold-induced endothelial injury with liquid nitrogen in the right carotid arteries, then were given a high-fat diet for eight weeks. Rabbits in group B were only fed a high-fat diet for eight weeks. After completion of the preparatory regimen, triggering of plaque rupture was attempted by local injection of liquid nitrogen in two groups. Before and after triggering, the serum lipid levels, hsC-RP, MMP-9 and PAI-1 of plasma were assayed. 48 hours after triggering, all rabbits were killed by an overdose of intravenous pentobarbital sodium. The right carotid arteries were quickly removed for light microscopy, electron microscopy and immunohistochemistry. Results After 8 weeks of high-fat diet, the serum lipid levels were significantly higher than baseline at the beginning of the experiment. After triggering in group A, the concentration of hsC-RP,MMP-9 and PAI-1 was significantly higher than the levels before triggering. All rabbits in group A had an acutely ruptured plaque and rupture-driven occlusive thrombus formation 48 hours after triggering, but none in group B. Importantly, the cold-induced lesion in our model is reminiscent of human atherosclerotic plaques in terms of architecture, cellular composition, growth characteristics, and patterns of lipid accumulation. Conclusions This study demonstrated that atherosclerotic plaque rupture and thrombosis could be established by cold-induced endothelial injury with liquid nitrogen, which is simple, fast and inexpensive. The novel model can be used to study the pathogenesis and therapies of atherosclerotic plaques lead to acute coronary events and stroke.