Compound48/80对载脂蛋白E基因敲除小鼠颈总动脉套环诱导斑块的影响

Effects of Compound 48/80 on Plaque Induced by Perivascular Common Carotid Collar Placement in Apolipoprotein E Gene-Knock Out Mice

目的采用肥大细胞脱颗粒剂———Compound 48/80作用于颈总动脉套环的载脂蛋白E基因敲除小鼠,以探讨肥大细胞脱颗粒对动脉粥样硬化斑块的影响及其可能作用机制。方法载脂蛋白E基因敲除小鼠高脂高胆固醇饲料喂养,行右颈总动脉套环术后分为实验组和对照组,分别腹腔注射Compound 48/80或D-hank’s。第4次注射后30 min,安乐死,取材。全自动生物化学分析仪测定血清中脂质含量,比色法测定血清中类胰蛋白酶活性,苏木素—伊红染色观察颈总动脉病理改变,甲苯胺蓝肥大细胞染色,免疫组织化学检测平滑肌肌动蛋白和巨噬细胞特异性抗原在斑块内的表达。结果Compound 48/80对血清脂质水平无明显影响。Compound 48/80明显刺激肥大细胞脱颗粒(80.6%±17.8%比13.5%±4.1%,P<0.01),升高血清中类胰蛋白酶活性(0.57±0.13 u/L比0.36±0.10 u/L,P<0.05)。套环能加速颈总动脉斑块形成(未套环侧颈总动脉斑块面积均为0,套环侧颈总动脉均有斑块形成),Compound 48/80增大套环侧颈总动脉斑块最大横截面积(58 500±7 500μm2比8 600±2 800μm2,P<0.01),并使管腔最大狭窄程度加重(81%±15%比41%±12%,P<0.05)。Compound 48/80使颈总动脉斑块内α平滑肌肌动蛋白表达量增加(1 219±364 iu比522±137 iu,P<0.05)和巨噬细胞特异性抗原表达量增加(426±133 iu比169±38 iu,P<0.05)。结论套环能加速载脂蛋白E基因敲除小鼠颈总动脉斑块形成。Compound 48/80使套环侧颈总动脉斑块最大横截面积和颈总动脉最大狭窄程度增加,其机制可能与其刺激肥大细胞脱颗粒促使平滑肌细胞增殖和巨噬细胞聚集有关。

Aim To investigate the effects of mast ceils degranulation on plaque development and their possible mechanisms in animal experiments by dealing apohpoprotein E gene-knock out （apoE-/- ） mice which had been placed perivascular common carotid collars with mast ceils degranulator-Compound 48/80. Methods 12-weck-old male apoE^-/- mice were fed a western-type diet and operated with perivascular right common carotid collar placement. 4 weeks after surgery, mice were divided into 2 groups with 20 mice each. The experimental mice were intmperitoneally injected with Compound 48/80, 0.5 μg/g, every other day; the control mice received the same injection of an equal volume of D-Hank＇s. Thirty minutes after 4th injection, animals were sacrificed to obtain carotid sections. Sections were routinely stained with hematoxylin and eosin. Corresponding sections on separate slides were stained with toluidine blue and y with antibodies against a macrophage-specific antigen or a-smooth muscle aetin. Results Administration of Compound 48/80 did not affect the lipid contents of mice serum. However, the percentage of degranulated mast cells （80.6% ± 17.8% vs 13.5% ±4.1%, P 〈0.01） and the activityof tryptase in serum （ 0.57 ± 0.13 u/L vs 0.36 ± 0.10 u/L, P 〈 0.05 ） were significantly increased. There were no pathological changes in common carotids non-collar placement but atheromatous plaques oceured in common carotids collar placement of both groups. Significant increase in plaque area of maximum cross section（58 500±7 500μm^2 vs8 600±2 800μm^2, P〈0.01）, the degree of lumen stenosis （81% ± 15% vs 41% ± 12%, P 〈 0. 05 ） and the expressions of a-smooth muscle actin（ 1 219 ± 364 iu vs 522 ± 137 iu, P 〈 0. 05 ）and macrophage-specific antigen （426 ± 133 iu vs 169 ± 38 iu, P 〈 0. 05） were detected in plaque of common carotids collar placement in the experimental group. Conclusions Perivascular common carotid collar placement can accelerate atherosclerotic plaque formation in apolipoprotein E-knock out mice. Compound 48/80 increases plaque area of maximum cross section and the degree of lumen stenosis by promoting proliferation of smooth muscle cells and acetumulation of macrophages.