Figure 6. Time-dependent effects of
imatinib on PDGF-induced versus insulin-induced receptor
phosphorylation. Serum-deprived (24 h) RGC-5 cells were pretreated
without (control) or with 10 µM imatinib for increasing time intervals
(3 h and 24 h). Subsequently, control and imatinib-treated cells were
stimulated with either 30 ng/ml PDGF or 30 nM insulin for 6 min. The
cell lysates were subjected to immunoblot analysis for receptor
tyrosine phosphorylation (A,B) using the indicated primary
antibodies (See Methods). To normalize the changes in protein
phosphorylation in the immunoblots, we used β-actin as an internal
control. Note: For data analyses, PDGF- or insulin-induced receptor
phosphorylation in the absence of imatinib was normalized to 100%. The
respective bar graphs shown are the mean±SEM values from 3 to 4
experiments. The asterisk indicates a p<0.05 compared with the
respective PDGF-induced receptor phosphorylation.
