Ang-Ⅱ对血管内皮细胞ET-1 mRNA表达水平的影响及茶多酚的保护作用

Effects of Ang-Ⅱ on expression of ET-1 mRNA in vascular endothelial cell and the protective effect of tea polyphenol

目的观察Ang-Ⅱ对血管内皮细胞ET-1 mRNA表达水平的影响及茶多酚的保护作用。方法将培养的血管内皮细胞随机分为四组:空白对照组(仅给予细胞培养液)、单纯Ang-Ⅱ组(细胞培养液中加入Ang-Ⅱ,使其终浓度为10-7mol/L)、Ang-Ⅱ+小剂量茶多酚组(在单纯Ang-Ⅱ组的基础上加入茶多酚,使茶多酚的终浓度为5 mg/L)、Ang-Ⅱ+大剂量茶多酚组(在单纯Ang-Ⅱ组的基础上加入茶多酚,使茶多酚的终浓度为25 mg/L)。以RT-PCR方法检测血管内皮细胞的ET-1 mR-NA表达水平。结果①与空白对照组相比,单纯Ang-Ⅱ组血管内皮细胞的ET-1 mRNA表达水平显著增高(P<0.01);②与单纯Ang-Ⅱ组相比,两个Ang-Ⅱ+茶多酚组大鼠的心肌ET-1 mRNA表达水平显著降低(P<0.01);③Ang-Ⅱ+大剂量茶多酚组的ET-1 mRNA表达水平显著低于Ang-Ⅱ+小剂量茶多酚组(P<0.01)。结论Ang-Ⅱ可使血管内皮细胞ET-1mRNA表达水平显著增高,茶多酚可抑制这一作用,且其作用与剂量有关。

Objective To investigate the effects of Ang- Ⅱ on the expression of ET-1 mRNA in vascular endothelial cell（ VEC） and the protective effect of tea polyphenol. Methods Cultured VECs were randomly divided into 4 groups： control group, Ang-Ⅱ group,Ang- Ⅱ ＋ low dose of tea polyphenol group and Ang- Ⅱ ＋ high dose of tea polyphenol group. The VECs were given cell culture medium in control group,and Ang- Ⅱ with the last concentration of 10^-7 mol/L in Ang- Ⅱ group. After administration of Ang- Ⅱ, VECs were given tea polyphenol with the last concentration of 5 mg/L and 25 mg/L in Ang- Ⅱ ＋ low dose of tea polyphenol group and Ang- Ⅱ ＋ high dose of tea polyphenol group,respectively. The expression of ET-1 mRNA was evaluated by RT-PCR. Results （1）The expression level of ET-1 mRNA in Ang- Ⅱ group was significantly higher than in control group（P〈0.01）. （2）The expression levels of ET- 1 mRNA in Ang- Ⅱ ＋ low dose of tea polyphenol group and Ang- Ⅱ ＋ high dose of tea golyphenol group were significantly lower than in Ang- Ⅱ group（ P 〈 0.01）. （3）The expression level of ET-1 mRNA in Ang- Ⅱ ＋ high dose of tea polyphenol group was significantly lower than that in Ang- Ⅱ ＋ low dose of tea polyphenol group（P 〈 0.01）. Conclusion Ang-Ⅱ could increase the expression of ET-1 mRNA in VEC, but tea polyphenols inhibits the expression of ET-1 mRNA in a dose-dependent manner.