The role of PTKs. The cells were pretreated for 15 minutes with the specific PTK inhibitor genistein (37 μmol/L) or the inactive genistein analog daidzen (39 μmol/L), followed by 1 hour of incubation with 100 nmol/L Et-1; data are shown in an autoradiograph (A) and graphically (B). CNS-EC were pretreated with geldanamycin (178 nmol/L) for 16 hours, followed by 1 hour of incubation with 100 nmol/L Et-1. The autoradiograph of the RPA for IL-8 mRNA is shown (C).