In hAECs (A) Superoxide dismutase and (B) catalase activity were determined after 24 hr exposure to IGF-1. There was no statistically significant alteration in enzyme activities. (C) Glutathione peroxidase activity was determined after 2 hr, 6hr, and 24 hr of exposure to IGF-1 (0 ng/mL; closed square, 50 ng/mL; open circle, 100 ng/mL; closed circle). *P<0.01 vs. 0 ng/mL IGF-1, n=4. #P<0.01 vs. 50 ng/mL IGF-1, n=4. (D) Total glutathione (GSH) levels were determined after 24 hr exposure to IGF-1.