Effects of lipopolysaccharide induction on inducible nitric oxide synthase in RAW264.7 macrophages

Objective To observe the effects of lipopolysaccharide (LPS) induction on inducible nitric oxide synthase(iNOS) in mice peritoneal macrophages. Methods The cells were divided into two groups randomly: control group (cells incubated without LPS), and LPS group (cells cultured in medium containing LPS with 0.01, 0.1, 1.0, 10mg/L respectively), then cells were harvested after 24h incubation. The iNOS gene expression was detected by reverse transcription-polymerase chain reaction (RT-PCR), iNOS protein expression was measured by western blot. Results western blot and RT-PCR analysis showed the expression of both iNOS mRNA and protein in cells from 0.1mg/L LPS group was significantly increased compared with control group (P0.05). Conclusion LPS can significantly increase the expression of iNOS at gene and protein level.