Fig 6. PD 98059 decreases the phosphorylation of ERK in HSVEC, but does not restore ATP-induced decrease in endothelial function in RA.

A. HSVEC were untreated (Ctrl), treated with ATP (2 mM), or ATP with 10 μM PD 98059 (PD+ATP) for 20 min and phospho p44/42 MAPK (P-ERK1/2) and total p44/42 (ERK1/2) proteins were quantitated with immunoblotting (adjusted to the loading control GAPDH). Cumulative data showing the phosphorylation (fold) of p ERK1/2 MAPK, * p < 0.05, N = 3, paired t-test. B. RA rings were untreated (Ctrl), treated with eATP (20 mM, ATP) or ATP with 20 μM PD 98059 (PD+ATP) for 1hr, then suspended in the muscle bath and the vessels were pre-contracted with phenylephrine (5 x 10⁻⁷ M) and treated with carbachol (5 x 10⁻⁷ M). N = 5 segments from different rats, * p<0.05, ns = nonsignificant, (1 way ANOVA).