通心络对新西兰兔动脉粥样硬化血小板活化的影响

目的:探讨通心络对动脉粥样硬化新西兰兔血小板的保护作用。方法:SPF级新西兰家兔42只,雌雄各半,随机分为7组:正常组,模型组,通心络超微粉低、中、高剂量组(0.15、0.3和0.6 g·kg~(-1)·d~(-1)),阿托伐他汀组(2.5 mg·kg~(-1)·d~(-1)),阿司匹林组(12.5 mg·kg~(-1)·d~(-1))。正常组给予普通饲料12周,模型组给予高脂饮食12周建立动脉粥样硬化模型,其余各组在给予高脂饲料的同时按剂量连续灌胃给药12周,饮水不限。末次给药后禁食12 h取材。取全血进行血常规检测,取血清、血浆分别进行血脂水平、血小板因子4(PF4)和可溶性CD62P(s CD62P)检测,流式细胞术检测血小板钙离子,电镜观察血小板超微结构,光镜下进行动脉粥样组织病理学观察。结果:与正常组比较,模型组新西兰兔血小板计数及血小板平均体积明显增加,血脂胆固醇(TC)、甘油三酯(TG)和低密度脂蛋白胆固醇(LDL-C)水平显著增高,血清PF4、sCD62P及血小板钙离子浓度表达明显增加(P0.05)。与模型组相比,各用药组均不同程度地降低血小板计数和血小板平均体积,血小板表达PF4、sCD62P水平及血小板内钙离子浓度明显降低,通心络低、中、高剂量组和阿托伐他汀组降低血清TC、TG和LDL-C水平(P0.05);电镜观察见正常组血小板形态规则,细胞器分布均匀,模型组血小板形态畸形,伪足明显,α颗粒及致密颗粒减少,胞浆内空泡增多,提示血小板活化状态,用药组均不同程度改善血小板形态,增加α颗粒及致密颗粒数量,胞质损伤减轻。组织病理学观察正常组内膜光滑完整,模型组内膜显著增厚,泡沫细胞大量聚集,斑块形成,用药组通心络高剂量组内膜增厚显著降低,泡沫细胞明显减少,斑块形成不明显,其它用药组均不同程度改善内膜增厚,降低泡沫细胞含量。结论:通心络可显著抑制动脉粥样硬化过程中血小板的活化状态,对于延缓动脉粥样硬化血栓形成具有重要临床治疗价值。

Effects of Tongxinluo on activation of platelet in rabbit model of atherosclerosis

AIM: To study the effects of Tongxinluo on the activation of platelets in a rabbit model of atherosclerosis. METHODS: New Zealand rabbits were randomly divided into 7 groups: normal group, model group, the groups treated with high, medium and low doses of Tongxinluo micropowder (0.15, 0.3 and 0.6 g·kg^-1·d^-1), atorvastatin group (2.5 mg·kg^-1·d^-1), and aspirin group (12.5 mg·kg^-1·d^-1). The rabbits in normal group was fed with common diet for 12 weeks, and the rabbits in model group were fed with high-fat diet for 12 weeks to establish atherosclerosis model. The rabbits in the rest groups were treated with the corresponding drugs, at the same time to give high-fat diet. Fasting for 12 h after the last treatment, whole blood was collected to perform the blood routine test, and to measure serum and plasma levels of lipids, platelet factor 4 (PF4) and soluble CD62P (sCD62P). Flow cytometry was used to analyze platelet calcium ion concentration. Electron microscopy was used for platelet superfine observations, and light microscopy for observing the pathological changes. RESULTS: Compared with normal group, the levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), platelet counts, and mean platelet volume in model group were significantly elevated, and the levels of PF4, sCD62P and calcium were also significantly increased (P < 0.05). Compared with model group, except aspirin group, the levels of TG, TC and LDL-C in high, medium and low doses of Tongxinluo groups and atorvastatin group were effectively decreased. The platelet counts and mean platelet volume in all treatment groups were markedly decreased, and the serum levels of PF4, sCD62P and Ca²⁺ in platelet (P < 0.05) were reduced. In electron microscopic observation, the shape of platelet was regular and organelles distributed uniform in normal group. However, in model group, the shape of platelet was irregular, pseudopodia forming was obviously observed, and α particles and dense granules decreased, indicating that the platelet was activated. To a different extent, the platelet shape, increase in the number of α particles and dense granules were improved in treatment groups and the damage of the cytoplasm was attenuated. Through histopathological observation, the intimal was smooth and complete in normal group. In the model group, the intimal thickness markedly increased, foam cell aggregated, and plaque was formed. Compared with model group, the intimal thickening and the number of foam cells were significantly decreased, and plaque formation was not obvious in atorvastatin group and high dose of Tongxinluo group. The pathological damages in the other treatment groups were alleviated in different degrees. CONCLUSION: Tongxinluo significantly inhibits the activation of platelets in the process of atherosclerosis, and has important clinical value to delay the atherosclerotic thrombosis.