氯沙坦对颈总动脉损伤大鼠血浆AngⅡ与血管TGF-β_1表达的影响

Effects of Iosartan on angiotensinⅡlevel and transforming growth factor beta expression in rats with carotid artery injury

目的观察氯沙坦对血管损伤大鼠血浆血管紧张素Ⅱ(AngⅡ)水平与血管转化生长因子β_1(TGF-β1)表达的影响。方法采用大鼠颈总动脉挤压术制备血管再狭窄模型,设假手术组、手术组、氯沙坦组,HE染色法观察血管形态学变化,放射免疫法测定血浆AngⅡ含量,免疫组织化学法测定颈总动脉TGF-β1的表达。结果假手术组动脉各层结构正常、清晰,无明显血管平滑机细胞(VSMC)增殖,颈总动脉损伤大鼠VSMC大量增殖,内膜显著增厚,氯沙坦组VSMC增殖程度降低;与假手术组比较,颈总动脉损伤大鼠血浆AngⅡ含量显著升高(P<0.01),血管平滑肌TGF-β_1表达显著增强(P<0.01);与手术组比较,氯沙坦组血浆AngⅡ含量无显著差异,血管平滑肌TGF-β_1表达显著下降(P<0.01)。结论AngⅡ与TGF-β_1参与血管再狭窄的形成,氯沙坦可通过阻断AngⅡ的作用与降低TGF-β_1表达实现抗血管再狭窄的作用。

Objective To study the effects of losartan on angiotensin Ⅱ （ Ang Ⅱ ） level of plasma and transforming growth factor beta（ TGF- β1 ） expression in rats with carotid artery injury. Methods The restenosis model was established by squzeezing rat carotid artery, treatment with losartan from three days before operation as losartan group. The morphologic change was observed by HE staining and Ang Ⅱ level of plasma was measured by radioimmunoassay. The expression of TGF- β1 was detected by immunohistochemical technique. Results Compared with sham group, the sections of injured carotid artery showed significantly intimal thickening with large numbers of VSMCs proliferating throughout intima and media, the Ang Ⅱ level of plasma and expression of TGF-β1 significantly increased（P 〈0.01 ）in operation group. Compared with operation group, there was no great difference in AngI Ⅱ content of plasma but the expression of TGF-β1 decreased obviously in losartan group（P 〈0.01 ）. Conclusions Ang Ⅱ and TGF-β1 take part in the vascular restenosis, Losartan is to be the therapy for vascular restenosis by blocking the effect of Ang Ⅱ and inhibiting TGF-β1 expression.