温脉通对实验性肢体动脉硬化家兔的防治作用及其机制的研究

目的观察温脉通对实验性家兔肢体动脉硬化性闭塞症(ASO)的疗效,并初步探讨其作用机理。方法将24只雄性日本纯种大耳白兔随机分为正常组、模型组和治疗组,每组8只。用实验性体内血栓形成测定仪对家兔右下肢股动脉定位电流刺激,同时给予高脂、高胆固醇饲料喂养制作ASO模型。治疗组术后第2天开始灌服中药复方温脉通,6周后取出定位血管,运用HE染色、Mas-son染色,光镜观察血管变化。用免疫组织化学方法检测血管平滑肌细胞(VSMC)增殖指标细胞增殖核抗原(PCNA),用TUNEL法检测细胞凋亡情况。用免疫组织化学方法检测血管壁基质金属蛋白酶-2(MMP-2)和其抑制因子(TIMP-1)。结果模型组血管内膜增厚,中膜VSMC明显增殖、迁移;温脉通防治组接近正常。模型组PCNA阳性数明显高于正常组(P<0.01),治疗组PCNA阳性数低于模型组(P<0.01)。模型组凋亡数稍高于正常组,治疗组凋亡数明显高于正常组和模型组(P<0.01)。凋亡与PCNA之比,治疗组明显高于模型组。模型组MMP-2表达明显高于正常组,尤其新生内膜表达增高明显,治疗组MMP-2表达明显低于模型组。正常组TIMP-1有明显表达,模型组新生内膜TIMP-1表达稍高于正常组、中膜表达稍低于正常组;治疗组表达增强,中膜稍高于模型组接近正常组。结论温脉通具有防治实验性家兔ASO作用,并可抑制病变血管VSMC增殖、诱导细胞凋亡。该方可能是通过调整细胞增殖速率与凋亡速率之间的动态平衡,减少内膜过度增生,减轻动脉粥样硬化程度,从而发挥防治ASO作用。该方能使ASO模型组家兔血管MMP-2表达下降,TIMP-1表达相对增加,调节MMPs/TIMPs使之平衡,从而抑制VSMC过度增殖、迁移,达到防治ASO的目的。

Preventive and therapeutic effect of Wenmaitong on experimental arteriosclerosis obliterans in rabbits and its mechanism

Objective To study the curative effect of Wenmaitong on experimental arteriosclerosis obliterans(ASO) in rabbits and its mechanism.Methods Tweenty-four rabbits were randomly divided into normal control group, ASO model group and Wenmaitong treatment group. The ASO model was established by local electric stimulation in femoral artery and high-lipid feeding for 6 weeks. The rabbits in the Wenmaitong treatment group were orally administered with Wenmaitong for 6 weeks. The pathological changes of femoral artery stained by HE and Masson were observed under the light microscope. PCNA expression in vascular smooth muscle cell (VSMC), matrix metalloproteinases-2(MMP-2) and tissue inhibitor of metalloproteinase-1(TIMP-1) expression in vessel wall were detected by immunohistochemistry. Apoptosis of cells in the vessel wall was assayed by TUNEL method.Results The intima of femoral artery was thickened and the VSMC in the media proliferated and migrated obviously in the model group, while in the Wenmaitong treatment group, intima and media tended to as normal as those in the normal control group. PCNA positive cells in the model group were more than those in the normal control group, while PCNA positive cells in the Wenmaitong treatment group were fewer than those in the model group. The apoptosis cells of the Wenmaitong treatment group were greater in number than that of the other two groups.Compared with the normal control group, MMP-2 expression of the model group increased, which was more obvious in newly born intima; Wenmaitong decreased MMP-2 expression significantly. There was TIMP-1 expression in the normal control group. In the model group, TIMP-1 expression was slightly higher in newly born intima and slightly lower in media than that in the normal control group, while Wenmaitong increased TIMP-1 expression.Conclusion The effects of Wenmaitong to prevent and cure ASO were regulating the balance between the rate of cell proliferation and apoptosis, reducing the proliferation of the intima as well as decreasing the procedure of atherosclerosis. Wenmaitong also regulates MMPs/TIMPs balance to inhibit over proliferation and migration of VSMC to prevent and cure ASO.