家兔颈总动脉血管内膜增生模型的探讨

A model of vascular intimal hyperplasia of the common carotid artery in rabbits

目的探讨家兔颈总动脉血管内膜增生模型的建立方法及影响因素。方法30只新西兰大白兔,雌雄各半,随机分为假手术组、高脂+单侧套管组(按造模时间分为2周、3周亚组)、高脂+双侧套管组(按造模时间分为2周、3周亚组)。单侧套管组在左侧颈总动脉外侧置一硅橡胶管(长度20 mm,内径1.0 mm)包裹血管并固定,双侧套管组在双侧颈总动脉外侧分别置一硅橡胶管包裹血管并固定。两组均于术后次日给予2%胆固醇饲料连续喂养2~3周。假手术组只行手术分离颈总动脉,不进行血管套管术,并饲喂普通饲料。分别于手术后第2周、第3周取损伤段颈总动脉观察病理形态学改变,采用形态计量学方法测定血管内膜增生指标,免疫组化法测定增生内膜中α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、骨桥蛋白(osteopontin,OPN)、Ⅰ型胶原(Col-Ⅰ)、炎性反应因子白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)的表达。结果高脂+颈总动脉硅橡胶管套管干预2周、3周后,颈总动脉出现明显的血管内膜增生,内膜面积(IA)、内膜厚度(IT)、内膜面积增生率(HRIA)、内膜厚度增生率(HRIT)均显著增加,其中双侧套管的内膜增生较单侧明显,干预3周内膜增生较2周严重。在双侧套管3周,血管内膜α-SMA表达显著降低、OPN、Col-Ⅰ、IL-1β、TNF-α表达显著增高。结论应用高脂+颈总动脉硅橡胶管套管法可成功建立血管内膜增生模型,以双侧颈总动脉套管干预3周以上为宜。

Objective To explore an establishment method and influencing factors of an intimal hyperplasia model of common carotid artery in rabbits.Methods Thirty New Zealand white rabbits,half male and half female,were randomly divided into a sham operation group,high fat+unilateral cannula group(divided into 2-and 3-week subgroups in accordance with the modeling time),and hyperlipidemia+bilateral cannula group(divided into 2-and 3-week subgroups in accordance with the modeling time).In the unilateral cannula group,a silicone tube(20 mm in length and inner diameter of 1 mm)was placed on the lateral side of the left common carotid artery and fixed,whereas in the bilateral cannula group,a silicone tube was placed on the lateral side of the bilateral common carotid artery and fixed.Both groups were fed a 2%cholesterol diet for 2-3 weeks starting from the day after the operation.In the sham operation group,the common carotid artery was separated,no vascular cannula was performed,and the rabbits were fed a regular diet.At 2 and 3 weeks after the operation,pathomorphological changes of the injured common carotid artery were observed,the index of intimal hyperplasia was measured by morphometry,and expression ofα-smooth muscle actin(α-SMA),osteopontin(OPN),type I collagen(Col-Ⅰ),inflammatory response factor interleukiN-1β(IL-1β),and tumor necrosis factor-α(TNF-α)in intimal hyperplasia was determined by immunohistochemistry.Results After treatment with high fat and the silicone tube for 2 or 3 weeks,intimal hyperplasia was found in the common carotid artery.The intimal area,intimal thickness,intimal area proliferation rate,and intimal thickness were increased significantly.Intimal hyperplasia in the bilateral cannula was more obvious than that in the unilateral side,and intimal hyperplasia at 3 weeks was more serious than that at 2 weeks.After 3 weeks of the bilateral cannula,expression ofα-SMA in the vascular intima was reduced significantly and expression of OPN,Col-Ⅰ,IL-1β,and TNF-αwas increased significantly.Conclusions A model of intimal hyperplasia can be successfully established using high fat and a common carotid artery silicone cannula,and the bilateral common carotid artery cannula should be applied for more than 3 weeks.