Fig. 4. Effect of SB 203580 on p38-MAPK activation by hyperosmotic stress. SB 203580 (1 µmol l–1) was added after a 15 min equilibration period and was present throughout the experiment. Phosphorylated (Ai) and total (Aii) p38-MAPK levels were assayed in extracts (100 µg of protein) from control hearts, as well as from hearts perfused under the various hyperosmotic conditions indicated, in the absence (–) or presence (+) of the inhibitor. The western blots shown are representative of three independent experiments performed with similar findings. Molecular mass markers (kDa) are shown to the right. (B) Densitometric analysis of phospho-p38-MAPK bands by laser scanning. Values are means ± S.E.M. for three independent experiments. *Value significantly different from control value (P<0.001).
