胰岛素促进血管内皮细胞产生一氧化氮的实验研究

EFFECTS OF INSULIN ON PRODUCTION OF NO AND NOS mRNA EXPRESSION IN BOVINE AORTIC ENDOTHELIAL CELLS

目的 :探讨胰岛素对血管内皮细胞增殖、NO产生和NOS基因表达的影响。方法 :培养牛主动脉内皮细胞 ,测定培养上清液中NO氧化产物NO-2 的水平并应用定量RT/PCR技术检测内皮细胞NOSmRNA的表达水平。结果 :①胰岛素对大血管内皮细胞无细胞毒作用 ,也不影响细胞增殖 ;②在 1～ 15 μg/ml浓度范围内 ,胰岛素加强内皮细胞释放NO ,且呈剂量依赖的方式 ,NOS特异性抑制剂L NAME可阻抑之 ;③胰岛素轻度增加NOSmRNA表达水平 ,但无统计学意义。结论 :胰岛素既不影响大血管内皮细胞增殖 ,也不影响内皮细胞NOSmRNA表达水平 ,但以剂量依赖的方式加强内皮细胞产生NO ,推测其诱导NO产生的机制可能是通过酶活性的诱导 。

Aim: In order to explore the regulation of the production of nitric oxide (NO) and the expression of nitric oxide synthase (NOS) gene in bovine aortic endothelial cells (BAEC) by insulin. Methods:The NO - 2 which is the production of NO in the culture medium was determined based on Griess reaction. Quantitative RT/PCR technique was performed to quantitate the levels of NOS mRNA in BAEC. Results: ① Insulin neither affected BAEC proliferation, nor had cytotoxic effect. ②Over a concentration range of 1～15 μg/ml, insulin stimulation of BAEC resulted in a dose dependent production of NO in the culture supernatants 2 hours later, with a maximum at 12 hours and this effect was completely blocked by L NAME.(3) NOS mRNA was slightly greater in BAEC after exposed to insulin, but without statistical significance. Conclusion: Since the endothelial cell proliferation and the expression of NOS mRNA was not affected with insulin, our data suggested that the insulin-induced NO production was mediated via the activation of NOS activity.