The NF-κB inhibitors pyrrolidine dithiocarbamate (PDTC) and quinazoline (6-Amino-4-(4-phenoxypheny lethylamino), QNZ) blocked the effects of GRO/KC on K currents. QNZ was dissolved in Ethanol. PDTC or QNZ was added 1 h before GRO/KC and was present throughout the incubation period. Neither PDTC nor QNZ had an effect on K currents in control cells (P = 0.867 and 0.999, respectively). *, significantly different from all other groups at this voltage. In PDTC experiments, GRO/KC (N = 18 cells), GRO/KC+PDTC (N = 18) were from 4 cultures, control (N = 13) and PDTC (N = 11) were from 4 cultures; in QNZ experiments, GRO/KC (N = 26), GRO/KC+QNZ (N = 26) were from 7 cultures, control (N = 6) and QNZ (N = 9) were from 2 cultures.