Fig. 2. Time course of the effect of excessive NaCl concentration upon p38-MAPK phosphorylation in the amphibian heart. (Ai) Phospho-p38-MAPK was detected in extracts (100 µg of protein) from control hearts (C), hearts perfused with 0.5 mol l–1 sorbitol for 15 min (S), or hearts perfused with excess of NaCl (206 mmol l–1 final concentration) in bicarbonate-buffered saline for various time periods. (Aii) Total p38-MAPK levels in identical samples, as a control for loading. (Aiii) Phospho-p38-MAPK was also detected in extracts (100 µg of protein) from hearts reperfused with normal buffer after a 2 min perfusion with excess of NaCl. The western blots shown are representative of three independent experiments. Molecular mass markers (kDa) are shown to the right. (B,C) Densitometric analysis of phospho-p38-MAPK bands by laser scanning. The results are means ± S.E.M. for three independent experiments. Asterisks indicate values significantly different from control values; *P<0.001, **P<0.01.
