(A) Western blots of phosphorylated ERK1/2 (pERK1/2) and total ERK2 following intracellular acidosis for 0, 1, 3, 6, 10 and 20 min, and quantitative data from six separate experiments. Data are expressed as fold phosphorylation normalized to control (0 min; open bar). (B) Western blots of phosphorylated p90RSK (pRSK) and total p90RSK (RSK), and quantitative data from six separate experiments. (C) Western blots of phosphorylated ERK1/2 (pERK1/2) and total ERK2 in cells following exposure to vehicle (con) or 100 μM phenylephrine (PE), or to intracellular acidosis for 0 or 3 min, and quantitative data from six separate experiments. Data are expressed as fold phosphorylation normalized to vehicle control (con). *P<0.05 compared with control.