FIGURE 7.

ER Ca²⁺ release mediated the effect of ATP on eNOS Ser-635 phosphorylation in BAECs. A, effects of BAPTA-AM (50 μm) on ATP-induced ERK1/2 activation and eNOS Ser-635 phosphorylation. BAECs were preloaded with BAPTA-AM for 30 min and then exposed to ATP. As shown, ATP (20 μm) stimulated ERK1/2 activation and corresponding eNOS Ser-635 phosphorylation, and these effects were prevented by intracellular Ca²⁺ chelation. Representative blots are shown from three independent experiments. B, quantitative analyses of the effects of BAPTA-AM on ATP-elicited eNOS Ser-635 phosphorylation. C, quantitative analyses of the effects of BAPTA-AM on ERK1/2 activation in ATP-treated cells (means ± S.E.; *, p < 0.05 versus control; **, p < 0.01 versus control; n = 3).