阿奇沙坦酯对大鼠颈总动脉球囊损伤后内膜增生的抑制作用及机制探讨

Inhibitory Effect and Mechanism of Azilsartan Medoxomil on Carotid Artery Intimal Hyperplasia in Balloon-Injured Rats

目的探讨新型降压药阿奇沙坦酯(azilsartan medoxomil,TAK-491)能否抑制球囊损伤后血管内膜增生及其可能机制。方法选取清洁级雄性200~250g SD大鼠48只,随机分为4组,即假手术组、模型组、阿奇沙坦酯低剂量组、阿奇沙坦酯高剂量组,每组12只。建立模型后,阿奇沙坦酯低剂量组与高剂量组SD大鼠分别按2mg/kg和4mg/kg每天给予3ml药物灌胃,模型组和假手术组大鼠每天用3ml生理盐水灌胃。于术后14、28天取大鼠颈总动脉行HE染色,观察血管形态学变化,同时计算内膜面积(IA)、中膜面积(MA)及内膜/中膜面积比(IA/MA)。免疫组化技术测量增殖细胞核抗原(PCNA)、Toll样受体4(TLR4)、核因子-κB(NF-κB)p65表达变化结果,酶联免疫吸附测定(ELISA)血清中肿瘤坏死因子-α(TNF-α)及白细胞介素-6(IL-6)水平。结果与模型组对比发现,药物低、高剂量组术后14、28天IA、IA/MA明显减少(P<0.05),颈总动脉的PCNA、TLR4、NF-κB p65蛋白的表达明显降低(P<0.05),血清中TNF-α、IL-6表达明显降低(P<0.05)。与假手术组进行对比发现,手术组术后14、28天IA、IA/MA明显增加(P<0.05),颈总动脉的PCNA、TLR4、NF-κB p65的表达明显增加(P<0.05),血浆中TNF-α、IL-6表达明显增加(P<0.05)。结论阿奇沙坦酯可以减轻损伤后血管再狭窄发生率,其作用机制可能是通过抑制TLR4介导的NF-κB通路,减少了下游炎性相关因子TNF-α、IL-6等的表达,继而减少内膜增生而实现的。

Objective To investigate the inhibitory effect of a new antihypertensive drug on carotid artery intimal hyperplasia in balloon-injured rats and its possible mechanism.Methods A total of 48 SD rats were randomly divided as follows：sham operation group,model group,low-dose Azilsartan medoxomil group and high-dose Azilsartan medoxomil group（n=12）. The rats in sham operateion group and model group were treated by by gavage with 3ml normal saline every day,and rats in low-dose Azilsartan medoxomil group and high-dose Azilsartan medoxomil group were treated by by gavage at adose of 2mg/kg and 4mg/kg Azilsartan medoxomil（3ml）every day.14 and 28 days after operation,we can observe the morphological changes of the injured arteries by HE staining and measure intimal area（IA）,medial area（MA）,the intimal/medial area ratio（IA/MA）.The expression of PCNA,TLR4,NF-κB p65 in each group were detected by immunohistochemistry and the plasma level of TNF-α,IL-6 were detected by enzyme-linked immunosorbent assay（ELISA）.Results Compared with the model group,the intimal area and the intimal/medial area ratio were significantly reduced in the low-dose group and hige-dose group （P〈0.05）. The expression of PCNA, TLR4 and NF-κB p65 in carotid artery were significantly lower （P〈0.05）. The plasma level of TNF-α、IL-6 were significantly lower （P〈0.05）. Compared with the sham operation group, the intimal area and the intimal/medial area ratio were significantly increased in the operation group （P〈0.05）and the expression of PCNA, TLR4 and NF-κB p65 in carotid artery were significantly increased （P〈0.05）. The plasma level of TNF-α、IL-6 were significantly increased （P〈0.05）.Conclusion Azilsartan medoxomil can alleviate the incidence of vascular restenosis.The mechanism of action possibly was related to reducing the expression of inflammatory factors such as TNF-α,IL-6 by TLR4/NF-κB pathway and inhibiting the carotid artery intimal hyperplasia.