(a) Effect of bradykinin (24 hours at 0.1μM) on PA activity from primary culture proximal tubular cells pretreated (24 hours) with TNF-α (150 U/ml) and IFN-γ (500 U/ml) (boxed part of the figure) or non-pretreated. TGF-β, 10 ng/ml; HOE-140, 0.1 μM; N^G-nitro-L-arginine methyl ester (L-NAME), 0.5 mM; lovastatine, 5 μM. (b) Western blot of B2 receptor (B2R) expression. (c) Increase in intracellular calcium ([Ca²⁺]_i) following bradykinin (0.1 μM) stimulation (time of stimulation 5 minutes). Values are mean ± SEM of five different experiments. *P < 0.05 compared with control cells. Representative blots or traces are shown.