Analysis of apoptosis induced by perfluorooctane sulfonates (PFOS) in mouse Leydig cells in vitro.

To explore the possible mechanism of perfluorooctane sulfonates (PFOS's) reproductive toxicity, mouse Leydig cells cultured in vitro were exposed to a serial concentration of PFOS for four more days of culture. Apoptosis during the process was checked. After 24 h, apoptosis occurred to all of the groups ≥ 50 μg/mL PFOS. After 72 h, 37.5 μg/mL dose also showed apoptosis, and the most apoptosis signals, averagely 18 per well, were observed in 62.5 μg/mL dose group. An increase in ROS (p < 0.05) and a decrease of mitochondrial membrane potential (p < 0.01) was confirmed in those groups with ≥ 12.5 μg/mL dose. ROS levels peaked in 50 μg/mL and 62.5 μg/mL groups, nearly two-folds higher than control. PFOS was also observed to down-regulate the protein expression of Bcl-2 and to up-regulate that of Bax. The apoptosis induced by PFOS in mouse Leydig cells was shown to be related to mitochondrially mediated pathways and to involve oxidative stress.