血管紧张素Ⅰ抑制血管紧张素Ⅱ诱导的血管平滑肌细胞增殖

The role of angiotensinⅠin the proliferation of vascular smooth muscle cells induced by angiotensin Ⅱ

目的探讨血管紧张素-(1-7)[Ang-(1-7)]对血管紧张素Ⅱ(AngⅡ)诱导的大鼠血管平滑肌细胞(VSMCs)增殖的影响。方法采用组织贴块法培养VSMCs,取生长良好的第3～5代细胞用于实验。随机分为对照组、AngⅡ组、Ang-(1-7)组、AngⅡ+Ang-(1-7)组、AngⅡ+Ang-(1-7)+(A-779)组,通过3H胸腺嘧啶(3H-TdR)掺入法测定VSMCs的DNA合成,用结晶染色的方法检测细胞数目,观察VSMCs的增殖情况。结果①与对照组比,AngⅡ(100nmol/L)孵育细胞24h后可明显诱导VSMCs3H-TdR掺入量增加;Ang-(1-7)(1000nmol/L)可减少3H-TdR掺入量。②与AngⅡ组比较,Ang-(1-7)(10nmol/L、100nmol/L、1000nmol/L)呈浓度依赖性的抑制AngⅡ诱导的VSMCs3H-TdR掺入量。加入Ang-(1-7)特异性受体阻断剂A-779后,Ang-(1-7)此作用消失。③结晶染色结果显示,AngⅡ可诱导VSMCs数目明显增加(P<0.05)。Ang-(1-7)可抑制AngⅡ诱导的VSMCs增加,亦呈浓度依赖性(P<0.05)。结论Ang-(1-7)能抑制基础和AngⅡ诱导的VSMCs增殖,通过其特异性受体发挥作用。

Objective To explore the effect of angiotensin-（1-7） [ Ang-（1-7） ] on the proliferation of vascular smooth muscle cells （VSMCs） induced by angiotensin Ⅱ （Ang Ⅱ ）. Methods The primary culture of VSMCs was performed using tissue explant method. Cells at passage 3 to 5 were used for experiment and were randomly divided into control group,Ang Ⅱ group, Ang-（1-7） group, Ang Ⅱ ＋ Ang-（1-7） group and Ang Ⅱ ＋ Ang-（ 1-7 ）＋（A-779） group. The synthesis of DNA was measured by incorporation of 3H -thymidine （3H-TdR） and the proliferation of VSMCs was measured by crystal violet staining. Results （1）Compared with the control, 3H-TdR incorporation was significantly increased after incubating the VSMCs with 100 nmol/L Ang Ⅱ for 24 hours. However 1000 nmol/L Ang-（1-7） decreaced the 3H-TdR incorporation. （2） Compared with the Ang Ⅱ control, Ang-（1-7） with （10 nmol/L, 100 nmol/L, 1000 nmol/L） does-dependently inhibited proliferation of VSMCs with no cytotoxic effect. The effect of Ang-（1-7） could be blocked by its specific receptor blocker A-779. （3）The crystal violet staining result show that Ang Ⅱ increased the cell number （P〈0.05）,and Ang：（1-7） inhibited the increase of cell number induced by Ang Ⅱ .Conclusion Ang-（ 1-7 ） could inhibit the proliferation of cultured rat＇s VSMCs induced by Ang Ⅱ via its specific receptor.