刺蒺藜对老年自发性高血压大鼠胸主动脉血管重塑的影响

Effect of Tribulus Terrestrisl on Thoracic Aorta Vascular Remodeling of Spontaneous Hypertension Rats

目的观察刺蒺藜对老年自发性高血压大鼠(SHR)胸主动脉血管重塑的影响及其可能作用机制。方法将30只SHR随机分为刺蒺藜组、缬沙坦组和模型组各10只,10只WKY大鼠作为正常组。刺蒺藜组给予刺蒺藜浓缩液17.2 mg/(kg·d),缬沙坦组给予缬沙坦胶囊13.35 mg/(kg·d),模型组和正常组给予等量生理盐水。各组灌胃给药,每周给药6天,每日1次,连续8周。实验结束后比较各组大鼠血压情况(包括收缩压、舒张压、平均动脉压、脉压),观察大鼠胸主动脉形态改变,检测胸主动脉中羟脯氨酸含量、血管紧张素Ⅱ1型受体(AT1)、转化生长因子β(TGF-β)蛋白表达和核因子κB(NF-κB)通路重要分子mRNA表达(包括NF-κB p65、IKKα、IKKβ、IKBα)。结果与正常组比较,模型组大鼠收缩压、舒张压、平均动脉压、脉压均明显升高(P<0.05);与模型组比较,刺蒺藜组及缬沙坦组收缩压、舒张压、平均动脉压均显著下降,刺蒺藜组脉压亦明显下降(P<0.05)。刺蒺藜组和缬沙坦组大鼠血管形态、血管内壁及内皮细胞较模型组有不同程度缓解和改善,胶原纤维沉积状态减轻。与模型组比较,刺蒺藜组和缬沙坦组羟脯氨酸含量下降,AT1和TGF-β蛋白明显减少,NF-κB p65、IKKβ、IKBα的mRNA表达显著下调,IKKα显著上调(P<0.05);而刺蒺藜组和缬沙坦组组间比较,差异无统计学意义(P>0.05)。结论刺蒺藜具有降低老年SHR血压、抑制主动脉血管重塑的作用,其机制可能与降低胸主动脉胶原含量和调控NF-κB信号通路有关。

Objective To examine the impact of Tribulus Terrestrisl on thoracic aorta vascular remodeling of spontaneous hypertension rats（ SHR） and the possible mechanism. Methods Thirty SHR were randomized into Tribulus Terrestrisl group,valsartan group and model group,10 rats in each group. Ten Wistar Kyoto（ WKY） rats were the normal group. The Tribulus Terrestrisl group was given Tribulus Terrestrisl concentrated solution 17. 2 mg /（ kg·d）. The valsartan group was given valsartan capsule 13. 35 mg /（ kg·d）. The model group and the normal group were given equivalent normal saline. All groups were given drugs by intragastric administration,6 days every week,once every day,for 8 weeks. After the experiment was finished,blood pressure situation including systolic pressure,diastolic pressure,mean arterial pressure and pulse pressure in all groups was compared. The shape changes of thoracic aorta were examined. The content of hydroxyproline in thoracic aorta was detected,so were the protein expressions of angiotensinⅡtype 1 receptor（ AT1） and transforming growth factorβ（ TGF-β）,as well as the mRNA expressions of important molecules（ including NF-κB p65,IKKα,IKKβ and IKBα） of nuclear factorκB（ NF-κB）pathway. Results Compared with the normal group,systolic pressure,diastolic pressure,mean arterial pressure and pulse pressure in the model group increased（ P〈0. 05）. Compared with the model group,systolic pressure,diastolic pressure and mean arterial pressure in the Tribulus Terrestrisl group and the valsartan group decreased; pulse pressure in the Tribulus Terrestrisl group decreased（ P〈0. 05）. Compared with the model group,rats＇ vascular shape,vessels inter wall and endothelial cells in the Tribulus Terrestrisl group and the valsartan group were relieved and improved by different levels; collagen fiber accumulation reduced. Compared with the model group,the content of hydroxyproline in the Tribulus Terrestrisl group and the valsartan group decreased; AT1 and TGF-βproteins reduced. The mRNA expressions of NF-κB p65,IKKβ and IKBαdown-regulated,while the mRNA expression of IKKαup-regulated（ P〈0. 05）. The difference of the Tribulus Terrestrisl group and the valsartan group was not significant（ P〉0. 05）. Conclusion Tribulus Terrestrisl might decrease the blood pressure of elderly SHR and inhibit aorta vascular remodeling. The mechanism might relate to reducing the content of collagen in thoracic aorta and regulating NF-κB signal pathway.