一氧化氮在17-β雌二醇抑制血管平滑肌细胞增殖和原癌基因c -fos表达中的作用

实验利用大鼠血管平滑肌细胞（vascular smooth muscle cells,VSMC)作为模型,观察17-β雌二醇（E2）对VSMC增殖和原癌基因c-fos表达的影响,并探讨VSMC源性一氧化氮（NO）在基中的作用,检测指标包括NO释放的测定,细胞计数、^3H-Tdr掺入,噻唑蓝（MTT）测定和c-fosmRNA表达,结果显示,E2（10^-12-10^-8mol/L)呈浓度依赖性地促进VSMC中NO的释放;10^-8mol/LE2能明显抑制10%小牛血清（FCS）和10^-7mol/L内皮素-1（ET-1）诱导的细胞增殖和DNA合成,E2的抑制作用均可被雌激素受体（ER）拮抗剂tamoxifen(10^-7mol/L)和一氧化氮合酶抑制剂L-NAME（10^-6mol/L)明显减轻;E2（10^-8mol/L)可明显抑制10^-7mol/LET-1诱导的VSMCc-fos表达,这种抑制作用可被L-NAME（10^-6mol/L)明显减轻,这些结果提示E2能抑制VSMC增殖和原癌基因c-fos表达,这种促进VSMC的NO释放密切相关,而且该作用至少部分通过ER介导。

17beta-Estradiol inhibits vascular smooth muscle cell proliferation and c -fos expression: role of nitric oxide

Rat vascular smooth muscle cells (VSMC) were used to study the effect of 17beta -estradiol (E(2)) on cellular proliferation (cell counting), DNA synthesis ((3)H thymidine incorporation), MTT, c -fos mRNA expression and nitric oxide (NO) release. The results obtained showed that E(2) (10(-12) 10(-8) mol/L) induced NO release from VSMC in a concentration-dependent manner; 10(-8) mol/L E (2)significantly inhibited VSMC cellular proliferation and DNA synthesis induced by 10% FCS and 10(-7) mol/L ET-1, which was obviously reversed by 10(-7)mol/L tamoxifen and 10(-6) mol/L L-NAME; after a pretreatment for 24 hours, 10(-8)mol/L E(2) significantly inhibited VSMC c -fos mRNA expression induced by 10(-7)mol/L ET-1, which was also obviously reversed by 10(-6) mol/L L-NAME. These results suggest that the inhibitory effects of E(2) on VSMC cellular proliferation and c -fos mRNA expression are closely related with NO release in VSMC, which is, at least, partly medicated by ER.