PCB153-induced oxidative stress and cell apoptosis on cultured rat Sertoli cells

摘要

In this study, we explored the temporal characteristics of superoxide dismutase (SOD) activity, malondialdehyde (MDA) concentration, and the effect of oxidative stress on DNA damage, and cell apoptosis after exposure to 2,4,5,2',4',5'-hexachlorobiphenyl (PCB153) on cultured rat Sertoli cells (SC). SOD activity and MDA concentration were determined after cell exposure to 10, 20, 30 mu mol L-1 PCB153 for 6, 12, 24, 36 or 48 h. Antioxidant N-acetyl-L-cysteine (NAC) was added to one group as a pre-treatment at the time point having the best dose-effect relationship. DNA damage, cell apoptosis, and morphological observation were determined by comet assay, flow cytometry, and fluorescence photomicrographs, respectively. After exposure to PCB153, SOD activity increased initially, but decreased subsequently. Each group reached a respective maximum value after 24 h when MDA concentration started increasing. No significant difference was observed in DNA damage after 24 h exposure, but cell apoptosis increased with the level of PCB153, although NAC-pretreatment provided protection. These were corroborated by the morphological observation. These findings suggest that 24 h was the best time point to determine oxidative stress indicators after exposure to PCB153 on cultured rat SC. Furthermore, PCB153-induced oxidative stress could increase cell apoptosis, while DNA damage was not evident.