EPCs express higher levels of MnSOD, catalase, and glutathione peroxidase. EPCs, HUVECs, and HMVECs were lyzed and expression of (A) MnSOD, catalase, and glutathione peroxidase was analyzed by Western blot. A representative ERK1/2 serves as loading control. Representative blots out of 3 independent experiments are shown. (B) Blots were scanned and expression of MnSOD, catalase, and glutathione peroxidase was quantified by densitometric analysis. The ratios for these enzymes are shown. Data are mean ± SD, n = 3. *P < .05 versus HUVECs and versus HMVECs.