Figure 5. Effect of IGF-I on the binding of DCN to IGF-IR. Aged-1 cells were serum-starved for 16 h, and then either treated with 200 ng/ml IGF-I (IGF-I) for 5 min or left untreated (U). Cells were harvested for co-immunoprecipitation assays and Western blot analyses for DCN and IGF-IR.