Time course effects of activin-A on ActRI mRNA levels. IEVT cells were incubated with or without activin-A (10 ng/ml) for 1, 3, 6, 12, 24 hours. cPCR was performed to measure ActRI mRNA levels and data were also normalized for β-actin value. *,(p < 0.05) versus control. **,(p < 0.01) vs control. Data present mean ± SEM of three experiments.