通心络通过降低循环血管紧张素Ⅱ水平及抑制局部氧化应激反应预防血管痉挛

Tongxinluo Prevented Vasospasm Through Lowering Circulation Angiotensin Ⅱ Level and Restraining Local Oxidative Stress

目的探讨通心络超微粉剂预防硅胶管包裹大鼠颈动脉血管痉挛的机制。方法 48只雄性WistarKyoto大鼠分成4组:对照组、小剂量通心络组[200 mg/(kg.d)]、中剂量通心络组[400 mg/(kg.d)]和大剂量通心络组[800 mg/(kg.d)]。用硅胶管包裹大鼠颈动脉造成血管外膜慢性损伤。包管手术前后各给药1周。于术后1周用超声血流量仪测大鼠双侧颈动脉血流量,并观察血管对局部应用5-羟色胺的反应。取大鼠心腔血测血清血管紧张素Ⅱ浓度;取双侧颈动脉标本,用RT-PCR方法检测血管组织AT1R、AT2R及p22phox mRNA的表达。结果硅胶管包裹大鼠颈动脉1周,颈动脉血流量降低(P=0.0002),血管对5-羟色胺的收缩血管反应增强(P<0.05),血管组织AT1R、AT2R及p22phox的表达均明显增加(AT1R增加135%,P=0.0020;AT2R增加76%,P=0.0061;p22pox升高2.89倍,P<0.0001)。大剂量、中剂量通心络超微粉剂均能改善包管侧颈动脉血流量及血管对5-羟色胺的反应敏感性(P<0.05),降低大鼠血清血管紧张素Ⅱ浓度(中剂量通心络组P=0.0480;大剂量通心络组P=0.0183),不影响包管侧颈动脉AT1R mRNA表达(P>0.05);大剂量通心络轻度上调损伤部位血管组织AT2R mRNA的表达(升高26%,P=0.0323)。小剂量通心络超微粉剂对包管侧颈动脉血流量、血管对5-羟色胺的收缩反应、循环血管紧张素Ⅱ水平、血管血管紧张素Ⅱ受体及p22phox mRNA表达均无明显影响(P>0.05)。结论通心络超微粉剂通过降低循环血管紧张素Ⅱ水平以及抑制局部氧化应激反应有效预防血管外膜慢性损伤所致的血流量减少及血管对5-羟色胺收缩反应敏感性增高。

Aim The present study was undertaken to investigate the possible mechanism of Tongxinluo on preventing vasoconstriction and vascular hypersensitivity to 5-hydroxytryptamine induced by the injury of the adventitia. Methods Wistar Kyoto rats were assigned to 4 treatments（n=12 for each group）： vehicle,low dose of Tongxinluo [200 mg/（kg·d）],middle dose of Tongxinluo [400 mg/（kg·d）] and high dose of Tongxinluo [800 mg/（kg·d）].After 1 week of treatment,adventitia injury was induced by positioning a silicone collar around the right carotid artery for one week.Blood flow and vascular reactivity to serotonin were determined 1 week after injury,the blood from the rat＇s heart was taken to measure the concentration of angiotensinⅡ（Ang Ⅱ） in the serum with the ELISA,and both side of carotids were harvested for RT-PCR analysis. Results Collar-induced adventitia injury decreased the carotid blood flow（P=0.0002）,increased the vascular reactivity sensitivity to 5-hydroxytryptamine,and upregulated the expression of AngⅡ type 1（AT1）receptor（135% increase,P=0.0020）,Ang ⅡII type 2（AT2）receptor（76% increase,P=0.0061）,and p22phox（2.89 fold increase,P〈0.0001）in collared arteries.Low dose of Tongxinluo did not affect vasoconstriction function,serum AngⅡconcentration,or the expressions of AngⅡ receptors and p22phox.Treatment with medium dosage and high dosage of Tongxinluo can effectively improve the carotid blood flow,normalize the hypersensitivity to 5-hydroxytryptamine（all with P〈0.05）,lower serum AngⅡ concentration（middle dosage group：26.31±6.82 ng/L vs 45.21±4.52 ng/L,P=0.0480;high dosage group： 20.51±2.51 ng/L vs 45.21±4.52 ng/L,P=0.0183）,restrained the increase of p22phox expressions（79.1% decreasing in middle dosage group,P=0.0002;83.2% decreasing in high dosage group,P=0.0001）,did not affect the AT1 receptor expression,while high dose of Tongxinluo increased AT2 receptor expression. Conclusion Tongxinluo can effectively prevent the vasoconstriction and the vascular hypersensitivity to 5-HT induced by the adventitia injury in rat carotid through lowering serum AngⅡ level and restraining the significantly enhanced oxidative stress induced by the adventitia injury.