Figure 7.

Effects of PI3K and eNOS inhibition and Ca²⁺ chelation on EF-mediated MEK phosphorylation: (a) addition of PI3K inhibitor LY294002 did not abolish EF-induced increase in pMEK levels, when compared with no-EF controls (n = 4, p < 0.05), suggesting that this pathway may not be critical for EF-mediated angiogenic cell responses. (b) Interestingly, addition of Ca²⁺ chelator BAPTA resulted in significantly reduced pMEK levels, when compared with no-EF controls, which was similar to the trends in cell responses observed in the presence of MEK inhibitor (figure 4). (c) eNOS inhibition using l-NAME did not affect pMEK levels in low-frequency and no-EF groups, and effectively abolished high-frequency EF-induced increase in MEK phosphorylation (n = 4, p < 0.05). These results indicate the involvement of Ca²⁺ and eNOS pathways in EF-mediated MEK pathway activation.