Figure 2.

Time- and dose-dependent effects of Cd²⁺, Cu²⁺, and Hg²⁺ on ROS formation by PC12 cells measured spectrofluorometrically using DCFH₂-DA as the ROS-sensitive probe. The results are expressed in % to corresponding control (*P < 0.05 compared to untreated control; n = 3–7 independent experiments).