【摘要】 ①目的　了解在炎症递质脂多糖 (LPS)及细胞因子的刺激下 ,一氧化氮合酶 (NOS)的底物精氨酸的来源。②方法　采用Northern印迹杂交及Western免疫印迹杂交方法 ,检测LPS、干扰素γ(IFNγ)及肿瘤坏死因子α(TNFα)刺激大鼠星状胶质C6细胞中精氨酸的再生体系———瓜氨酸 NO循环相关酶的表达。③结果　LPS及细胞因子刺激C6细胞后 ,iNOS被诱导生成 ;同时精氨酸代琥珀酸合成酶 (AS)在mRNA及酶蛋白水平表达增高 ;培养液中加入精氨酸 ,可见NO的合成 ;用瓜氨酸代替精氨酸 ,亦可出现NO的合成。④结论　在活化的C6细胞中 ,精氨酸的再生体系———瓜氨酸 NO循环对于合成NO是非常重要的。更多还原

【Abstract】 Objective\ To verify whether NO synthase(NOS ) can be synthesized by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL) via citrulline NO cycle in rat astroglioma C6 cells. \ Methods\ C6 cells were treated with bacterial lipopolysaccharide ( LPS), interferon γ (IFNγ) and tumor necrosis factor α (TNFα) and the expre ssion of the enzymes of the citrulline NO cycle was investigated by RNA blot an d immunoblot analyses. NO production from arginine and citrulline was also asses sed. \ Results\ iNOS mRNA and apoenzyme were induced 6-12 h after stimul ation with LPS and cytokines and decreased at 24 h. AS mRNA increased up to 12 h and decreased at 24 h. AS apoenzyme increased gradually up to 48 h. AL mRNA rem ained unchanged by stimulation. NO production from arginine was enhanced by trea tment with LPS and cytokines. NO production observed when arginine was replaced by citrulline. \ Conclusion\ NO production is enhanced in LPS and cytokine stimulat ed C6 cells due to induction of iNOS and that the citrulline arginine recycling is important for NO production.更多还原