Effect of antioxidant and NFκB on the induction of iNOS gene in rat pulmonary microvascular endothelial cells in vitro

AIM:To investigate the role of nuclear factor κB (NF_κB) in the induction of iNOS gene by TNFα and LPS in endothelial cells and the effect of antioxidant on the induction of iNOS. METHODS:Nitrite was determined based on Griess reaction. iNOS mRNA was analyzed using Northern blot. NF_κB in the cell nucleole was detected with electrophoretic mobility shift assay.RESULTS: (1)NO production and iNOS mRNA expression induced by LPS and TNFα was blocked by pyrrolidine dithiocarbamate(PDTC) or N-acetylcysteine(NAC). (2)LPS and TNFα triggered the activation and translocation of NF_κB, and PDTC or NAC inhibited the activation of NF_κB induced by LPS and TNFα. CONCLUSIONS:(1)The induction of iNOS gene by TNFα and LPS is dependent on the activation of NF_κB.(2)Antioxidants may inhibit the induction of iNOS gene through the inhibition of NF_κB activation.