Figure 7.

Arsenic inhibits phosphorylation of phosphoinositide 3-kinase (PI3K) in RBL-2H3 cells. RBL-2H3 cells were sensitized with anti-DNP IgE (0.1μg mL-1) for 1 hr before being treated with DNP-BSA Ag (1μg mL-1) ± 750ppb As for 5 min. Levels of (A) phosphorylation of the p85 subunit of PI3K and (B) total p85 subunit of PI3K were measured with a Fast Activated Cell-based ELISA kit. Data were plotted after correction for cell number (by use of crystal violet staining). Values represent mean (normalized to 0 ppb As) ± SEM of 3-4 experiments of triplicate samples. Statistical significance was determined by one sample t-test; **p<0.01.