通心络对自发性高血压大鼠血浆NO、ET及血管平滑肌iNOS表达的影响

Effect of Tongxinluo on Expression of Plasma NO,Endothelin and iNOS mRNA in Vascular Smooth Muscle in Spontaneously Hypertensive Rats

目的观察通心络对自发性高血压大鼠(SHR)血压、血浆内皮素(ET)、一氧化氮(NO)、血管紧张素II(Ang II)以及主动脉血管平滑肌组织(VSM)iNOS mRNA表达的变化。方法30只12周龄雄性SHR大鼠,随机分成3组,每组10只,分别为空白对照组、通心络小剂量组、大剂量组,年龄、性别配对的正常雄性WKY大鼠作为对照。各给药组均采用灌胃法给药,对照组给予等量蒸馏水。治疗12周。放免法测定血浆ET、Ang II浓度,NO浓度采用硝酸还原酶法测定,用RT-PCR检测VSM组织iNOS mRNA表达水平。结果与未治疗组SHR相比,大、小剂量通心络治疗均能在一定程度上抑制SHR大鼠血压升高(P<0.05);小剂量通心络治疗可降低血浆ET浓度(P<0.05),升高NO浓度(P<0.05),Ang II浓度无明显变化(P>0.05),VSM iNOS mRNA表达增强(P<0.05);大剂量通心络治疗可使血浆ET明显降低(P<0.01),Ang II浓度下调(P<0.05),NO浓度显著升高(P<0.01),VSM iNOS mRNA表达显著增强(P<0.01)。结论通心络治疗能有效降低SHR大鼠血浆ET、Ang II水平,促进VSM组织iNOS mRNA表达,增加血浆NO浓度,抑制血压的升高。

Objective To evaluate the effect of Tongxinluo on blood pressure, plasma endothelin （ET）, NO, angiotensin Ⅱ （ANG Ⅱ） and nitric oxide synthase （iNOS） mRNA expression in vascular smooth muscle （VSM） in spontaneously hypertensive rats （SHRs）. Methods 12-week-old male SHRs were divided into Tongxinluo low-dose group （n=10）, Tongxiuluo high-dose group （n=10）, and age and sex matched Wistar Kyoto rats were set as control group （n=10）. Tongxinluo groups were gastric perfused with Tongxinluo respectively and the control group with distilled water for 12 weeks. The levels of plasma ET and ANG II were measured by radioimmunoassay, the level of NO were assayed by nitrate reductase method, and iNOS mRNA expression in VSM was determined by RT-PCR. Results Compared with the control group, the increasing of blood pressure of SHRs was inhibited obviously in Tongxinluo groups （P〈0.05）. Compared with the control group, the level of plasma ET was lower （P〈0.05）, the level of NO was higher （P〈0.05）, the level of ANG II had no significant changes （P〉0.05）, and iNOS mRNA expression in VSM was higher in Tongxinluo low-dose group （P〈0.05）. Compared with the control group, the level of plasma ET was obviously lower （P〈0.01）, the level of NO was obviously higher （P〈0.01）, the level of ANG II was lower （P〈0.05） and iNOS mRNA expression in VSM was obviously higher in Tongxinluo high-dose group （/9〈0.01）. Conclusion Tongxinluo could significantly decrease the levels of plasma ET and ANG Ⅱ, promote the expression of iNOS mRNA, increase the level of plasma NO, and inhibite the increasing of blood pressure of SHRs.