N-乙酰半胱氨酸对人离体中性白细胞释放超氧阴离子的影响

Effect of N-acetylcysteine on the Stimulus-induced Superoxide Generation of Human Neutrophils in Vitro

目的用人离体中性白细胞研究N-乙酰半胱氨酸(N-acetylcysteine,NAC)对中性白细胞释放超氧阴离子的影响。方法细胞色素C还原法测定NAC对三种刺激剂介导的中性白细胞释放超氧阴离子量。用抗原抗体法检测丝或苏氨酸磷酸化。结果NAC可呈浓度依赖性抑制N-甲酰甲硫氨酰-亮氨酰-苯丙氨酸(fMLP)和佛波豆蔻醚乙酸盐(PMA)介导的中性白细胞释放超氧阴离子;而对花生四烯酸(AA)介导的中性白细胞释放超氧阴离子无影响。Western blot结果显示NAC可呈浓度依赖性抑制fMLP和PMA介导的丝氨酸或苏氨酸的磷酸化。结论NAC可能通过膜受体通道抑制细胞内的蛋白激酶C及其上游的蛋白质激酶,抑制中性白细胞释放超氧阴离子的产生。

Objective To study the effect of N-acetylcysteine on the stimulus-induced superoxide generation and the phosphorylation of human neutrophils in vitro. Methods We examine the effect of t N-acetylcysteine on sueproxide generation using the method of the reduction of cythrome.c.The stimulation of human neutrophils with N-acetylcysteine was induced by 3 stimuli,N-formyl-methionyl-leucyl-phenylalanine （fMLP）, phorbol 12-myristate 13-acetate （PMA） and arachidonic acid （AA）.The level of serine/threonine phosphorylation of neutrophil proteins detected using western blotting.Results N-acetylcysteine inhibits superoxide generation induced by fMLP and PMA in a concentration-dependent manner, however, do not affect AA-induced superoxide generation. Furthermore, in parallel to the effect on the fMLP- and PMA-induced superoxide generation,N-acetylcysteine inhibits fMLP- and PMA-induced serine/threonine phosphorylation in a concentration-dependent manner.Conclusion The inhibitory effect of N-acetylcysteine on fMLP- and PMA- superoxide anion generation is dependent on PKC or upstream of PKC signaling pathway.