论文部分内容阅读
目的观察非对称性二甲基精氨酸(asymmetric dimethylarginine,ADMA)对培养的大鼠腹腔巨噬细胞诱导型一氧化氮合酶(iNOS)表达的影响,探讨其在脂质沉积中的作用及机制。方法分组①正常对照组以PBS缓冲液与巨噬细胞共孵育,②氧化型低密度脂蛋白(oxLDL)组在巨噬细胞培养液中加oxLDL(50mg/L),③O+A组在巨噬细胞培养液中加oxLDL(50mg/L)和ADMA(20μmol/L),④O+A+L组在培养液中加ox-LDL(50mg/L)、ADMA(20μmol/L)、L-Arg(1.2mmol/L)。以硝酸还原酶法和化学比色法分别测定培养液中一氧化氮(NO)含量与iNOS活力,以RT-PCR和Western Blotting分别检测iNOSmRNA和蛋白表达。结果①OxLDL组与O+A组NO含量降低,iNOS活力升高,且以O+A组明显,与正常对照组比较差异均有统计学意义(均P<0.05);NO与iNOS呈负相关(r=-0.697,P<0.05)。②O+A组iNOS mRNA和蛋白表达增强,与正常对照组相比差异有统计学意义(P<0.05或P<0.01)。结论ADMA抑制大鼠腹腔巨噬细胞合成NO,增强iNOS基因与蛋白表达,可能是ADMA促使巨噬细胞转变为泡沫细胞、促进动脉粥样硬化发生发展的机制之一。
Objective To investigate the effect of asymmetric dimethylarginine (ADMA) on inducible nitric oxide synthase (iNOS) expression in cultured rat peritoneal macrophages and its role in lipid deposition mechanism. Methods ① The normal control group were incubated with PBS and macrophages, oxLDL (50 mg / L) in oxLDL group, macrophage OxLDL (50mg / L) and ADMA (20μmol / L) were added into the cell culture medium. The concentrations of ox-LDL (50mg / L), ADMA (20μmol / L) and L-Arg 1.2 mmol / L). Nitric oxide (NO) content and iNOS activity in culture medium were determined by nitrate reductase and chemical colorimetry, respectively. The expression of iNOS mRNA and protein was detected by RT-PCR and Western Blotting respectively. Results ① The NO content in OLDL group and O + A group were decreased and the iNOS activity was increased. The O + A group was significantly higher than that in normal control group (all P <0.05). NO and iNOS were negatively correlated r = -0.697, P <0.05). ② The expression of iNOS mRNA and protein in O + A group increased significantly compared with the normal control group (P <0.05 or P <0.01). Conclusion ADMA can inhibit the synthesis of nitric oxide synthase (NO) in rat peritoneal macrophages and enhance the expression of iNOS gene and protein, which may be one of the mechanisms by which ADMA can promote macrophages to foam cells and promote the development of atherosclerosis.