Delayed induction of free radicals in the liver after Cd and Cr exposure.

Liver tissue slices from Cd (A and C) and Cr (B and D) exposed animals were incubated with hydroxy-TEMPO with or without the •OH scavenger DMTU, and examined via ESR. Total free radical levels dose-dependently increased for both metal exposures 1, 3 and 7 days post-injection (A and B). An indication of the contribution of •OH to total ROS was determined by examining the differences in ESR peak height after the addition of DTMU (C and D). Cr exposure dose-dependently increased •OH production at the mid and high doses on days 3 and 7. Values are mean ±SE, n = 6–7 animals per group. *Significantly different from control on each day, p<0.05. ^†Significantly different from other days in the same dose.