L-精氨酸对高糖引起内皮功能失调的保护作用

Effects of L-Arginine on Human Umbilical Vein Endothelial Cell Induced by High Concentration Glucose

目的通过研究L-精氨酸和NG-硝基-L-精氨酸-甲基酯对人脐静脉内皮细胞产生一氧化氮和超氧阴离子的影响以探讨L-精氨酸对高糖引起内皮功能失调的保护作用。方法不同浓度L-精氨酸、NG-硝基-L-精氨酸-甲基酯、葡萄糖和胰岛素加入体外培养的人脐静脉内皮细胞,24 h后分别测定细胞培养液中一氧化氮合酶和超氧化物歧化酶活性及一氧化氮和超氧阴离子浓度。结果25 mmol/L葡萄糖使内皮细胞一氧化氮合酶活性增高,一氧化氮产生增加,超氧化物歧化酶活性下降,超氧阴离子产生增加;L-精氨酸对一氧化氮合酶、一氧化氮、超氧化物歧化酶的影响与对照组相比无显著性差异(P>0.05),但可以使超氧阴离子产生减少;25 mmol/L葡萄糖+L-精氨酸使内皮细胞一氧化氮合酶活性增强,一氧化氮产生增加,L-精氨酸可以改善高糖引起的超氧阴离子升高。不同浓度的胰岛素使内皮细胞一氧化氮合酶活性增高,一氧化氮产生增加,对超氧化物歧化酶活性和超氧阴离子产生无明显影响;不同浓度胰岛素+L-精氨酸使内皮细胞一氧化氮合酶活性增强,一氧化氮产生增加,对超氧化物歧化酶活性无明显影响,但可以使超氧阴离子水平降低。100μmol/L NG-硝基-L-精氨酸-甲基酯使内皮细胞一氧化氮合酶活性下降,一氧化氮产生减少,对超氧化物歧化酶活性无明显影响,但使超氧阴离子产生增加;25 mmol/L葡萄糖+NG-硝基-L-精氨酸-甲基酯使内皮细胞一氧化氮合酶活性下降,一氧化氮产生减少,但对高糖引起的超氧化物歧化酶活性下降和超氧阴离子升高无明显影响。10 mu胰岛素+10μmol/L NG-硝基-L-精氨酸-甲基酯和100 mu胰岛素+100μmol/L NG-硝基-L-精氨酸-甲基酯使内皮细胞一氧化氮合酶活性下降,一氧化氮产生减少,对超氧化物歧化酶活性无明显影响,但使超氧阴离子升高。结论L-精氨酸对一氧化氮合酶、一氧化氮、超氧化物歧化酶无明显影响,但可以使超氧阴离子产生减少;NG-硝基-L-精氨酸-甲基酯使内皮细胞一氧化氮合酶活性下降,一氧化氮产生减少,对超氧化物歧化酶活性无明显影响,但使超氧阴离子产生增加。

Aim To investigate effects of L-arginine and N^G-nitro-L-arginine methyl ester （L-NAME） on human umbilical vein endothelial cell （ hUVEC ） secreting nitric oxide （NO） and superoxide anion （ O2^- ）. Methods hUVEC was incubated with glucose, insulin, L-arginine and L-NAME respectively for 24 hours. The activity of nitric oxide synthase （NOS） and superoxide dismutase （ SOD ）, the concentration of NO and O2 in the supernatant of cultured hUVEC was measured at the end of the experiment. Results NOS activity, the concentration of NO increased, while SOD activity decreased and the concentration of O2 increased significantly in the presence of 25 mmol/L glucose. NOS, NO, SOD did not change significantly in the presence of L-arginine, while the concentration of O2 decreased significantly. The activity of NOS, the concentration of NO increased in thepresenee of 25mmol/Lglucose＋L-arginine, L-arginine may reverse the elevation of O2 which induced by glucose. NOS, NO increased in the presence of 10, 100, 1 000 mu/L insulin, while SOD and O2 did not change significantly. NOS, NO increased in the presence of L-arginine ＋ insulin, SOD activity did not change significantly while O2^- decreased. NOS activity and the generation of NO decreased in the presence of 100μmol/L L-NAME, while SOD activity did not change signiticanfly, however the. generation of O2 increased. NOS, NO decreased in the presence of 25 mmol/L glucose ＋ L-NAME, however SOD activity and the concentration of O2 did not change significantly. NOS, NO decreased in the presence of 10 mu insulin ＋ 10μmmol/L L-NAME and 100 mu insulin＋ 100μmol/L L-NAME, SOD activity did not change significantly, while the concentration of O2 increased. Conclusion NOS, NO, SOD did not change significantly while O2 decreased in the presence of L-arginine. NOS activity, the generation of NO decreased while O2^- increased in the presence of L-NAME in the supematant of cultured endothelial cell.