Effects of citropten and bergapten on IB3-1 and CuFi-1 cells. mRNA accumulation was studied by quantitative RT-PCR analysis. IL-8 expression was induced by exposure of IB3-1 (A) and CuFi-1 (B) to heat-inactivated PAO-1. White symbols: untreated IB3-1 or CuFi-1 cells, in the absence (-) or in the presence (+) of heat-inactivated PAO-1. Grey symbols, cells treated with IC25 bergapten; Black symbols, cells treated with IC25 citropten. Results represent the average ± S.D. of three independent experiments. For each experiment duplicate RT-PCR determinations were performed. (*) p < 0.05.