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.
Keywords: Apoptosis; mitochondria pathway; mouse Leydig cells; oxidative stress; perfluorooctane sulfonates.