摘要
目的 :探讨炎症过程诱生的一氧化氮 (NO)对内皮细胞的损伤及其作用机制。方法 :黄递酶法及Griess法检测可诱导性NO合酶 (iNOS)活性、NO-2 /NO-3 水平 ,RT -PCR技术分析iNOSmRNA的表达 ;同时观察NO产生后对内皮细胞的损伤作用。结果 :IL - 1β 2× 10 5U/L、TNF -α 5× 10 5U/L、γ -INF 2× 10 5U/L联用LPS(10mg/L)可诱导出高浓度NOS合成及NO产生 ,比单用这些细胞因子或LPS诱导的量高两倍多 ,iNOSmRNA的表达水平也显著增加 ;同时MDA及LDH释放率明显增加 ,细胞存活率下降 ,并伴随细胞受损的形态学改变。而单用上述细胞因子或LPS ,以及降低剂量或缩短处理时间 ,其诱生的NOS及NO与正常对照相比P >0 0 5 ;但MDA及LDH释放率仍增加明显。使用 2倍剂量的这些炎性细胞因子或延长处理时间到 48h ,与标准剂量及 2 4h组相比NOS和NO的增加虽不显著 ,但细胞生长受限更明显。NOS抑制剂能阻止NO的产生及其对细胞的损伤作用。结论 :炎性细胞因子及脂多糖可激活iNOS大量表达诱生高浓度的NO 。
AIM: To explore the mechanism underlying inducible nitric oxide (NO) caused injury of endothelial cells during inflammation. METHODS: The activity of iso-enzymes of NO synthase (NOS), NO level and iNOS expression were examined using NADPH method, Griess reaction and RT-PCR, respectively. Furthermore, the lactate dehydrogenase (LDH) release rate, malondialdehyde (MDA) content were also measured. RESULTS:Co-administration of cytokines (TNF-α 5×10 5 U/L, IL-1β 2×10 5 U/L, INF-γ 2×10 5 U/L) and LPS (10 mg/L) caused an obvious increase in NOS activity, NO levels (about two-fold) and a significant injury of the cells. At the same time, a significant increase in iNOS mRNA was also detected. Wheareas, treatment of the cells separately with cytokines or LPS for 24 h had no significant effect on NOS activity and NO level in cell lysates, however, it caused a significant increase in LDH release and MDA content. Also, the effect of cytokines and LPS on cell viability was concentration-and time-dependent. L-NMMA, a inhibitor of NOS, can suppress inducible NO production and protect cells against NO induced injury. CONCLUSION:Co-administration of cytokines (TNF-α, IL-1β and INF-γ) and LPS significant activated iNOS and NO production which, in turn, induced oxidative reaction in endothelial cells.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2001年第9期893-897,共5页
Chinese Journal of Pathophysiology