Fig. 7.

Quantification of ErbB1 immunoreactivity at individual pY sites after solution treatments of 5 min. These are the results of densitometry of blots similar to those shown in Fig. 6. For each treatment, pY-specific immunoreactivity at each ErbB1 site was first normalized to actin. A: ratios of ErbB1-pY to actin (ErbB1-pY/actin) for nominally CO₂/HCO₃⁻-free treatments, normalized to ErbB1-pY/actin for the nominally CO₂/HCO₃⁻-free HEPES treatment. B: ErbB1-pY/actin for nominally CO₂/HCO₃⁻-free HEPES and CO₂/HCO₃⁻ solutions, normalized to ErbB1-pY/actin for our Ctrl treatment (5% CO₂/22 mM HCO₃⁻). C: ErbB1-pY/actin for treatments like those in B but with and without the ErbB inhibitor PD-168393, normalized to ErbB1-pY/actin for the equivalent treatment without PD-168393. Sample sizes (n) are shown beneath each graph. †Bar for which all constituent data points are <0 (or >0) but not statistically different from 0. #Bar for which P < 0.05 (compared with 0 by a one-tailed, paired t-test); in the text, we state that the parameter “tends or tended” to rise/fall. *Bar that is significantly different from 0, even after the very conservative Bonferroni correction (P < 0.05 divided by the number of treatment solutions considered); in the text, we refer to the change as “significant.”