Figure 3.

Activation of kinases in HUVECs cultured in various O₂ levels. HUVECs were maintained at 18% O₂ or cultured in 5 or 1% O₂ for at least 5 d. Cells were then stimulated with histamine (10 µM) for 2 min (A) or 0–20 min (B), or laminar shear stress (15 dyn/cm²) for 0–30 min (C). Lysates were immunoblotted for p-AMPK or p-Akt and expressed relative to total kinase levels and β-actin as loading controls. Data are means ± sem (n = 5–6 different donors). Treatment with histamine or shear stress was significant (P < 0.05 vs. respective control) in relevant panels. *P < 0.05, **P < 0.01, ***P < 0.001 vs. 18% O₂; ^##P < 0.01 vs. 5% O₂.