血管紧张素Ⅱ2型受体对大鼠血管平滑肌增殖的影响及其机制

Effect of AT_2 receptor on the proliferation and the NOS expression in cultured adult rat VSMC

目的观察血管紧张素Ⅱ(AngⅡ)2型受体(AT2R)对培养的大鼠血管平滑肌细胞(VSMC)增殖的影响。方法将AT2RcDNA转染到培养的大鼠VSMC中,分别观察AngⅡ、AngⅡ+losartan、AngⅡ+PD123319等不同处理因素处理对VSMC的细胞数目以及PCNA、NOS表达的影响。结果losartan处理组细胞数目和PCNA表达量少于AngⅡ处理组,NOS表达量高于AngⅡ处理组,而PD123319处理组细胞数目和PCNA表达量显著高于AngⅡ处理,NOS表达量较之为少。结论激活AT2R能拮抗AngⅡ的由AT1R介导的促细胞增殖作用,这种作用可能与激活AT2R后NOS表达增多使NO合成增多有关。

AIM: To observe the effect of angiotensinⅡ subtype 2 receptor (AT_2 receptor) on the cultured rat aortic vascular smooth muscle cells. METHODS: The plasmid contained the cDNA of AT_2 receptor was transfected into cultured rat vascular smooth muscle cells. The effects of AngⅡ, Ang Ⅱ+losartan, Ang Ⅱ+PD123319 on the expression of PCNA, the NOS activity and the cell number were observed. RESULTS: The cell number and the expression of PCNA decreased after the cells were treated with losartan. When treated with PD123319, the cell number and the expression of PCNA increased, but the expression of NOS decreased. CONCLUSIONS: These data suggest that when being activated, AT_2 receptor inhibits the proliferation of vascular smooth muscle cells and antagonizes the effect of AT_1 receptor, such an effect may be related to the activation of NOS. [