国产猪胰弹性蛋白酶联合氯化钙浸泡法构建兔腹主动脉瘤模型

Establishment of abdominal aortic aneurysm model in rabbits by using domestic porcine elastase combined with calcium chloride immersion method

目的采用国产猪胰弹性蛋白酶联合氯化钙浸泡法构建简便稳定的兔腹主动脉瘤(AAA)模型。方法 48只新西兰大白兔随机分为动脉瘤组、蛋白酶组、氯化钙组和假手术组。剖腹手术游离一段长约1 cm腹主动脉,动脉瘤组游离动脉段以氯化钙和国产猪胰弹性蛋白酶浸泡20 min,蛋白酶组、氯化钙组分别仅以猪胰弹性蛋白酶、氯化钙浸泡20 min,假手术组由0.9%氯化钠溶液浸泡20 min。术后5、15、30 d采用彩色超声检测浸泡段腹主动脉直径,术后5、30 d每组分别处死6只实验兔作组织病理学和免疫组织化学检查。结果动脉瘤组实验兔均形成AAA,蛋白酶组仅形成1例,氯化钙组、假手术组均未见形成。动脉瘤组与其余各组组织病理学比较,动脉内膜和中膜较薄,胶原纤维和弹力纤维含量减少且修复增生不明显,基质金属蛋白酶(MMP)-2、MMP-9表达和炎性细胞浸润均明显增强。术后5 d蛋白酶组、氯化钙组可见血管破坏,术后30 d蛋白酶组与动脉瘤组相比可见内膜增生明显,中膜厚度恢复至正常水平,胶原纤维、弹力纤维和平滑肌细胞含量增多明显,MMP-2、MMP-9表达和炎性细胞浸润明显减弱。结论国产猪胰弹性蛋白酶联合氯化钙浸泡法可构建简便稳定的兔AAA模型。

Objective To establish a simple and stable rabbit model of abdominal aortic aneurysm(AAA)by using domestic porcine elastase combined with calcium chloride immersion method.Methods A total of 48 New Zealand white rabbits were randomly and equally divided into four groups with 12 rabbits in each group,including aneurysm group,porcine elastase group,calcium chloride group and sham-operation group.Laparotomy was performed for each rabbit,a abdominal aorta about 1 cm long was separated.The separated segment was immersed in the solution of calcium chloride and domestic porcine pancreatic elastase for 20 min(aneurysm group),in the solution of domestic porcine pancreatic elastase for 20 min(porcine elastase group),in the solution of calcium chloride for 20 min(calcium chloride group),and in 0.9%sodium chloride solution for 20 min(sham-operation group)respectively.At 5,15 and 30 days after treatment the diameter of immersed segment of abdominal aorta was measured with color ultrasound.Every 6 rabbits from each group were sacrificed each time at 5 days and 30 days after treatment,and the specimens were sent for histopathological and immunohistochemical examinations.Results Successful modeling of AAA was obtained in all experimental rabbits of aneurysm group,only one rabbit of porcine elastase group developed AAA,and no formation of AAA was found in both calcium chloride group and sham-operation group.Pathologically compared with other three groups,in aneurysm group the arterial intima and media were thinner,the contents of collagenous fiber and el astic fiber were decreased with less sings of repair and proliferation,the expressions of matrix metallo-proteinase-2(MMP-2)and MMP-9 as well as the degree of inflammatory cell infiltration were all significantly enhanced.Five days after the treatment,vascular destruction was detected in porcine elastase group and calcium chloride group;and 30 days after the treatment in porcine elastase group and aneurysm group obvious intimal hyperplasia was observed,the thickness of tunica media returned to normal level,the contents of collagenous fiber,elastic fibers and smooth muscle cells were markedly increased,while the expressions of MMP-2 and MMP-9 as well as the degree of inflammatory cell infiltration became obviously weakened.Conclusion A simple and stable rabbit model of AAA can be successfully established by using domestic porcine elastase combined with calcium chloride immersion method.