The comparison of chromium mediated cell responses in two different human cell lines

We have studied different biochemical indicators of chromium toxicity in the human epithelial-like cells (L-41) and human lung fibroblasts (HLF) distinctly differing in endogenous antioxidant defense activity. The resistance of cell system with the high level of antioxidant activities to chromium-induced damaging effect is prolonged in time, what points to antioxidants intricate role in cell physiology. The toxic chromium action leads to the significant inactivation of GPx (Glutathione peroxidase) from the very early stage (2 h) of Cr(V1) action to its whole exhaustion at the late stages. The differential modulation of intracellular redox state influenced cell recovery from initial oxidative stress at the nontoxic chromium concentration. The short-time increase of ROS level induced the cell cycle re-entry of HLF cells. The prolonged oxidative stress in L-41 cells resulted in the transient growth arrest. The development of apoptosis at the toxic concentrations was time-dependent in regards to the intrinsic level of antioxidant enzymes.