Figure 4.

Insulin stimulation of TGF-β1 generation is dependent on translation but not on de novo gene transcription. Confluent monolayers of HK-2 cells were growth arrested and insulin (5 μg/ml) added under serum-free conditions in the presence of increasing doses of either actinomycin (filled bars) or cycloheximide (shaded bars). Supernatant samples were collected 48 hours after the addition of insulin and TGF-β1 quantified by ELISA. Data represents mean TGF-β1 concentration corrected for total cell protein ± SD of eight individual experiments (*, P < 0.05).