toxicity in rats: Dietary 100 ppm perfluorooctane sulfonate (PFOS) fed to male mice and rats for 4 weeks caused hepatic steatosis through an unknown mechanism

PFOS (perfluorooctanesulfonic acid) perturbs TJ- and basal ES-protein localization in Sertoli cells. Sertoli cells isolated from 20-day-old rat testes were cultured in vitro for 3 days to form a cell epithelium with an established functional TJ-barrier, which mimicked the Sertoli cell BTB in vivo. This in vitro-based system has been widely used by investigators to study BTB dynamics, and many of the findings were subsequently confirmed by studies in vivo. Thereafter, these cells were treated with PFOS at 10, 20 or 50 µM for 24 hr. It was noted that PFOS perturbed the Sertoli cell TJ-permeability barrier function dose-dependently with PFOS at 50 µM was more effectively to perturb the TJ function than at 20 µM. The range of PFOS concentration at 20–50 µM (i.e., at 10–25 µg/ml) used in the study herein was shown not to be cytotoxic as recently reported from our laboratory, and no cytotoxicity was found at concentration up to 100 µM. The acceptable daily intake (ADI) of PFOS is 150 ng/kg/day. But since PFOS has a human elimination half-life of 5.4-year, a considerable level of PFOS could build up in humans in particular among industrial workers such as those who utilize PFOS for manufacturing of stain resistant carpets and fabrics.