Pyrrolidine dithiocarbamate prevents IL-1-induced nitric oxide synthase mRNA, but not superoxide dismutase mRNA, in insulin producing cells.

We presently investigated the effects of pyrrolidine dithiocarbamate (PDTC), a potent inhibitor of nuclear factor kappa B (NF-kappa B), on the induction of nitric oxide synthase (iNOS) and manganese superoxide dismutase (MnSOD) mRNAs by IL-1 beta in insulin-producing RIN cells. PDTC decreased by 90% both IL-1 beta-induced increase in medium nitrite accumulation (an indicator of NO production) and induction of iNOS mRNA expression. However, PDTC did not prevent induction of MnSOD mRNA by IL-1 beta. PDTC induced an early (45 min) expression of c-fos mRNA and potentiated IL-1 beta-induced c-fos expression. Our data suggest that NF-kappa B activation is necessary for iNOS, but not for MnSOD, mRNA expression in insulin producing cells.