幽门螺杆菌感染致兔动脉粥样硬化模型的超声表现

Ultrasound manifestations of Helicobacter pylori infection-induced atherosclerosis model in New Zealand white rabbit

目的应用二维彩色多普勒超声(2D-CDUS)研究幽门螺杆菌(Hp)感染的高脂血症兔颈动脉血管的物理性状及血流动力学参数的变化。方法 16只正常雄性新西兰大白兔先用高脂饮食喂养6周,采用酶标法测定血脂水平,确认为高脂血症后,随机分为对照组和实验组,每组8只,继续予高脂饲料喂养。实验组经兔耳缘静脉注射Hp标准菌株,对照组经兔耳缘静脉注射等量的0.9%氯化钠溶液。分别于实验前及实验第6、8周测定两组兔的血脂水平。分别于实验前及实验第6、12周,应用2D-CDUS测量兔颈内动脉内径(ICA-D)、颈总动脉内中膜厚度(CCA-IMT)、颈内动脉平均血流速度(ICA-Vmean)和阻力指数(ICA-RI),同时测量血流动力学参数,计算颈内动脉的血流量(ICA-Q)及颅脑总血流量(Q总),并观察内膜面有无斑块及斑块大小。结果实验第6周,两组兔的总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白-胆固醇(LDL-C)均较实验前显著升高(P值均<0.05);实验第8周,实验组TC、TG、LDL-C均较对照组显著升高(P值均<0.05)。实验第6周,两组兔的CCA-IMT、ICA-RI均较实验前显著升高(P值分别<0.01、0.05),ICA-Vmean、ICA-Q及Q总显著降低(P值均<0.05);实验第12周,实验组的CCA-IMT、ICA-RI均较对照组显著增加(P值分别<0.05、0.01),ICA-Vmean、ICA-Q及Q总均显著降低(P值均<0.05)。实验组有较小的颈动脉粥样硬化斑块形成。结论 Hp感染较易建立高脂血症兔颈动脉粥样硬化模型。2D-CDUS成像在建模过程中能便捷、客观地监测兔颈动脉血管的结构及血流动力学各项参数的变化。

Objective To apply two-dimensional color Doppler ultrasound（2D-CDUS）in studying the physic characteristics of carotid arteries and hemodynamic parameters changes in Helicobacter pylori（Hp）infection-induced hyperlipidemic rabbits.Methods Sixteen normal male New Zealand white rabbits were fed with high-fat diet for six weeks.Serum lipid levels were measured with enzyme linked immunosorbent assay（ELISA）and hyperlipidemia was confirmed.The animals were then equally randomized into a control group and an experimental group;both groups were continuously given high fat diet.The experimental group was injected with standard Hp strain into the ear vein and the control group was treated with normal saline.The blood lipids were determined before and during the 6th and 8th week of experiment.2D-CDUS was used to detect the rabbits＇ carotid artery diameter（ICA-D）,intima-media thickness（CCA-IMT）,plaque size,hemodynamic parameters and to calculate the internal carotid artery blood flow（ICA-Q）and cerebral blood flow（Qtotal）before the injection and six,twelve weeks after the treatment.Results The levels of total cholesterol（TC）,triglyceride（TG）,and low density lipoprotein-cholesterol（LDL-C）were significantly increased in both groups during the 6th week compared with those before experiment（P〈0.05）.The levels of TC,TG,and LDL-C in the experiment group were significantly higher than those of the control group during the 8th week of experiment（P〈0.05）.The CCA-IMT and ICA-RI in both groups during the 6th week were significantly higher than those before experiment（P〈0.01,0.05）,and ICA-Vmean,ICA-Q and Q were significantly decreased（P〈0.05）.During the 12th week after injection,the CCA-IMT and ICA-RI in the experimental group were significantly increased（P〈0.05,0.01）,and ICA-Vmean,ICA-Q and Q were significantly decreased（P〈0.05）.There were small atherosclerotic plaques in the carotid artery of the experiment group.Conclusion It is quite easy to use Hp infection to establish carotid artery atherosclerosis model in hyperlipidemic rabbit.2D-CDUS can easily and objectively monitor the changes of rabbits＇ carotid artery structure and hemodynamic parameters in the modeling process.（Shanghai Med J,2010,33：757-760）