Effect of protein kinase A (PKA) inhibitor on H₂O₂-promoted eNOS phosphorylation.

<p>In panel A, cardiac myocytes were incubated with H89 (1 µM, 30 min) or vehicle, then treated with H₂O₂ (25 µM, 15 min) and analyzed in immunoblots probed with antibodies as shown. Below each representative immunoblot are shown the results of densitometric analyses from pooled data, documenting the changes in phospho-eNOS (Ser1177), and phospho-VASP (Ser157) plotted relative to the signals present in unstimulated cells. Each data point represents the mean ± S.E. derived from at least three independent experiments; *indicates p<0.05 (<i>ANOVA</i>). Panel B shows representative immunoblots from experiments documenting the effects of A23187 (40 µM, 5 min) on cardiac myocyte protein phosphorylation responses. Panel C shows the results of immunoblots analyzed in lysates prepared from cells treated with phorbol 12-myristate 13-acetate (10 µM, 15 min). Cell lysates were analyzed in immunoblots probed with antibodies as indicated. The immunoblot images shown are representative of three independent experiments that yielded similar results. Below each immunoblot panel are the results of densitometric analyses from pooled data, showing the fold increase in protein phosphorylation (in arbitrary units), *indicates p<0.05.