Fig. 4. ERK1/2 and p90RSK phosphorylation after stretch. As reported previously [25], myocardial stretch (St) significantly increased ERK1/2 (A) and p90RSK (B) phosphorylation compared to non-stretched controls ("Control" or "C"). In the presence of the p38-MAPK inhibitor SB202190 ("SB"), myocardial stretch promoted a greater increase in ERK1/2 and p90RSK phosphorylation, effect that was not observed in muscles pre-treated with the inactive analogous SB202474 ("St+IA"). SB and IA alone did not modify the phosphorylation of either ERK1/2 (90±9 % of control, n=5 and 97 ±6 % of control, n=5, respectively) or p90RSK (105±4 % of control, n=5 and 93±8 % of control, n=4, respectively). * indicates p<0.05 vs. control, # indicates p<0.05 vs. St and St+IA.