钩藤碱对AngⅡ诱导大鼠血管平滑肌细胞增殖的抑制作用

 目的研究钩藤碱(rhynchophylline,Rhy)对血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)诱导大鼠血管平滑肌细胞(vascular smooth muscle cells,VSMCs)增殖的抑制作用及机制。方法采用细胞计数法和MTT比色法检测Rhy对AngⅡ诱导大鼠VSMCs增殖的影响;测定Rhy对AngⅡ作用的VSMCs上清液一氧化氮(nitric oxide,NO)含量和一氧化氮合酶(constitutive nitric oxide synthase,cNOS)活性的影响;实时定量聚合酶链式反应(RT-PCR)检测VSMCs中c-myc、NOS和高血压相关基因-1(hypertension related gene-1,rHRG-1)mRNA的表达。结果Rhy(3×10^-6～3×10^-7mol·L^-1)呈浓度依赖性地抑制AngⅡ诱导大鼠VSMCs的增殖,升高细胞上清液中NO的含量和NOS活性,降低c-myc mRNA,升高rHRG-1和NOS mRNA的表达。结论Rhy明显抑制AngⅡ诱导大鼠VSMCs的增殖,机制可能与增加VSMCs中NOS活性并促进NO的合成和释放以及下调c-myc、上调NOS和rHRG-1 mRNA的表达有关。

Inhibition of Rhynchophylline on Cultured Vascular Smooth Muscle Cells Proferation Induced by Angiotensin Ⅱ

OBJECTIVE To investigate the inhibition of rhynchophylline(Rhy),components of Uncaria rhyrchophylla(Miq.),on vascular smooth muscle cells(VSMCs) proliferation induced by angiotensin Ⅱ(AngⅡ),and explore the possible mechanisms.METHODS The effects of Rhy on VSMCs proliferation induced by Ang Ⅱ 10^-6 mol·L^-1 were determined by cytometry and methyl thiazolyl tetrazolium(MTT) assay,the effects of Rhy on the expressions of c-myc,constitutive NO synthase(NOS) and rat hypertension related gene-1(rHRG-1) mRNA were detected by RT-real time PCR,respectively.RESULTS Rhy(3×10^-6～3×10^-7 mol·L^-1) depressed VSMCs proliferation induced by Ang Ⅱ in a concentration-dependent manner,and increased the contents of NO and the activities of NOS in cultured cell.Furthermore,Rhy up-regulating the expressions of NOS and rHRG-1 mRNA,and down-regulated the expression of c-myc mRNA,respectively.CONCLUSION Rhy obviously attenuated the cultured rat VSMCs proliferation induced by Ang II.The mechanisms are,at least partly,due to an increase of the NOS activity,and promoting the synthesis and release of NO,and up-regulating the expressions of NOS and rHRG-1 mRNA,and down-regulating the expression of c-myc mRNA.