Effect of pertussis toxin and signalling inhibitors on dopamine-induced ERK1/2 activation in AmphiAmR11-expressing CHO-K1 cells.

<p>For the pertussis toxin experiment, AmphiAmR11-expressing CHO-K1 cells were pre-incubated with pertussis toxin (200 ng/ml) for 16 hours prior to serum-starvation for 2 hours in the absence of the toxin. Cells were then stimulated for 5 mins with 10 nM dopamine (open bar) or F-12 Hams control (black bar). For all other inhibitors, AmphiAmR11-expressing CHO-K1 cells were serum starved for 2 hours including incubation with 10 µM inhibitor or F-12 Hams control for the final 20 (AG1296 and AG1478) or 30 (PP2, LY294002, Ro31-8220, U0126, U73122 and U73343) minutes. Cells were then stimulated for 5 minutes with 10 nM dopamine (black bars) or F-12 Hams control (open bars) in the presence of the inhibitor. Basal measurement in the absence of dopamine and inhibitor (first black bar) and the dopamine-only response in the absence of inhibitor (first open bar) are shown. (A) Representative blots from three or four independent experiments. (B) Summary of the quantified blots. **, <i>p</i> < 0.01 versus dopamine-only; ***, <i>p</i> <0.001 versus dopamine-only. Data are expressed as the mean + SEM. n = 3 - 4. DA, dopamine; PTX, pertussis toxin; Ro, Ro 31-8220; LY, LY294002.