Figure 1. IL-1beta-induces NO release (a.) and iNOS expression (b.) in INS cells in an NF-kappaB-dependent manner. a. INS 832/13 cells were incubated in the absence or presence (600 pmol/L; 24 h) of IL-1beta as indicated in the figure. PTDC (0-100 μmol/L) was also present in the incubation medium (2 h prior to the addition of IL-1beta) as indicated in the figure. NO releasedinto the medium was quantitated using Griess reagent. Data, which are expressed as NO released into the medium, were mean±SEM from three independent studies carried out in triplicates. b. INS lysate protein from cells treated with PDTC (50 μmol/L) alone or with IL-1beta were separated by SDS-PAGE, transferred onto nitrocellulose membranes and subjected to immunoblot analysis with an antibody directed against iNOS or alpha-tubulin as described under Material and Methods. Data are representative of three separate experiments with comparable results.