精氨酸类似物对一氧化氮合酶的影响

目的 研究新精氨酸类似物对一氧化氮及诱导型一氧化氮合酶（iNOS）的影响。方法 脂多糖刺激巨噬细胞，检测不同浓度新精氨酸类似物对诱导型iNOS的抑制程度；胰岛素刺激脐静脉内皮细胞，检测新精氨酸类似物对于内皮细胞的iNOS的抑制作用。结果 （1）新精氨酸类似物可显著抑制脂多糖刺激的巨噬细胞产生一氧化氮，并呈剂量依赖性。而对胰岛素刺激的内皮细胞一氧化氮产生无明显影响。（2）新精氨酸类似物可显著降低巨噬细胞iNOS的活性，对于巨噬细胞的结构型iNOS活性及内皮细胞的iNOS活性无明显影响。（3）新精氨酸类似物对于巨噬细胞iNOS的蛋白表达无明显影响。结论 新精氨酸类似物是一种具有高度选择性的iNOS抑制剂。

Highly selective inhibition of inducible nitric oxide synthase in vitro by a tripeptide as a new arginine analog

Objective To investigate the inhibitory effect of a tripeptide, a new arginine analog, on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS). Methods Macrophages challenged with lipopolysaccharide were cultured to test the inhibitory effect of the arginine analog of different concentrations on iNOS. Primarily cultured human umbilical vein endothelial cells (HUVECs) treated with insulin were used to test the effect of the analog on endothelial NOS (eNOS). Results The new arginine analog significantly inhibited NO production in the macrophages in a dose-dependent manner, but had little effect on insulin-stimulated NO production in HUVECs. The new analog could significantly suppress iNOS activity, but had no significant inhibitory effect on constitutive NOS activity or eNOS activity. Western blot analysis showed that the new analog did not significantly affect the protein expression of iNOS. Conclusion The new analog is a NOS inhibitor with high selectivity on iNOS.