FIG. 3.

Perivascular stem cells in 6% oxygen have elevated reactive oxidative species and greater superoxide dismutase activity. (A) Cells grown in 6% (filled symbols) or 21% (open symbols) oxygen were loaded with dichlorofluorescine diacetate before plating into media containing 0 (circles) or 20 μg/mL (triangles) UBM digest material. Fluorescence intensity was quantified at excitation wavelength (Ex) 485 nm and emission wavelength (Em) 538 nm at 5 min intervals. (B) Cells grown in 6% (filled columns) or 21% (open columns) oxygen were exposed to 0 or 20 μg/mL UBM digest material for 6 h before quantification of cellular superoxide dismutase activity against a superoxide dismutase standard curve.