Fig. 1.

Effect of phosphatase inhibitors on p44/42 MAPK activation in cardiac fibroblasts treated with ET-1. A nonselective protein tyrosine phosphatases (PTPs), sodium orthovanadate (Na₃VO₄, 100 μM), significantly increased phosphorylated p44/42 MAPK under both basal condition and ET-1 stimulation, suggesting that PTPs are involved in activation of p44/42 MAPK in cardiac fibroblasts.* p < 0.001, ET-1 or Na₃VO₄ alone vs control; † p < 0.001, Na₃VO₄ plus ET-1 vs ET-1 alone; # p < 0.001, Na₃VO₄ plus ET-1 vs Na₃VO₄ alone (n = 3 - 4 per group)