Objective To explore the possible mechanism of nitric oxide(NO) involved in iron-mediated cytotoxicity on renal tubular cells, meanwhile to estimate the effect of reactive oxygen sepcies scavenger on iron-mediated cytotoxicity and its relation to nitric oxide. Methods in this study, the relationship between NO production and lactate dehydrogenase(LDH) release were observed in primary subconfluent proximal tubular cells coincubated with different doses of NTA-Fe and lipopolysaccharide(LPS) alone or in combination. NO production was monitored by NO2 -- concentration in supernatant based on Griess reaction. Meanwhile, semi-quantitative RT-PCR was applied to detect the inducible nitric oxide synthase (iNOS) mRNA level induced by NTA-Fe and LPS together. In addition, experimental groups were exposed to reactive oxygen species (ROS) scavengers to determine the impact of the interaction between NO and ROS on iron-mediated cytotoxicity. Results After 12-hour coincubation, NTA-Fe could increase both LDH release and NO2 production in a dose-dependent manner (P 0. 05 ) although tubular injury was aggravated (P