Effect of antioxidant and NF_κB 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.