FIGURE 1.

ET-1-induced MCP-1 and IL-6 mRNAs require de novo RNA synthesis. ET-1 (100 nm) was added to serum-starved mesangial cells for the times indicated, and mRNA levels for MCP-1 (A) and IL-6 (B) were quantified by qPCR normalized for GAPDH. Vehicle is medium alone without ET-1. Cells were preincubated for 30 min with 5 μg/ml actinomycin D (ActD) to block RNA polymerase II activity before adding ET-1 at time 0. Data are means ± S.D. for four independent experiments performed in duplicate. **, p < 0.01 versus vehicle or ET-1 + actinomycin D.