FIG. 4.

p38 mediates the stimulatory effects of ET-1, PE, and LIF on ANF expression in myocytes. Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding p38 and MKK6b (300 ng each). The cells were treated with hypertrophic agonists ET-1 (10 nM) (A), PE (50 μM) (B), or LIF (1 nM) (C), in the presence (+) or absence of the specific p38 inhibitor SB202190 (20 μM), as indicated. The ANF-Luc activity was determined as described in the legend to Fig. 3. The results are presented as means ± standard errors (error bars) and represent six individual experiments.