Bisphenol A (BPA) is a monomer used mainly in the synthesis of polycarbonates and epoxy resins. Percutaneous absorption is the second source of exposure, after inhalation, in the work environment. However, studies on this route of absorption are lacking or incomplete. In this study, percutaneous BPA absorption was measured in vivo and ex vivo in the rat, and ex vivo in humans. An approximately 12-fold difference in permeability between rat skin and human skin was found, with permeability being higher in the rat. In addition, inter- and intra-individual variability of up to tenfold was observed in humans. No accumulation of BPA in the skin was found during exposure. The skin clearance rate following exposure was estimated at 0.4 μg/cm²/h. Ex vivo and in vivo percutaneous absorption fluxes of BPA in the rat were in the same range (about 2.0 μg/cm²/h), suggesting that extrapolation to the in vivo situation in humans may be possible. The European tolerable daily intake (TDI) of BPA is 50 μg/kg body weight. However, many research projects have highlighted the significant effects of BPA in rodents at doses lower than 10 μg/kg/day. A 1-h occupational exposure over 2,000 cm² (forearms and hands) may lead to a BPA absorption of 4 μg/kg/day. This is 8% of the European TDI and is very close to the value at which effects have been observed in animals. This absorption must therefore be taken into account when evaluating risks of BPA exposure, at least until more relevant results on the toxicity of BPA in humans are available.

It has been suggested that access to high caloric food attenuates stress response. The present paper investigates whether access to commercial chow enriched with glucose and fat, here referred to as comfort food alters behavioral, metabolic, and hormonal parameters of rats submitted to three daily sessions of foot-shock stress. Food intake, anxiety-like behaviors, and serum levels of insulin, leptin, corticosterone, glucose and triglycerides were determined. The rats submitted to stress decreased the intake of commercial chow, but kept unaltered the intake of comfort food. During the elevated plus maze (EPM) test, stressed rats increased the number of head dipping, entries into the open arms, as well as the time spent there, and decreased the number of stretched-attend posture and risk assessment. These effects of stress were independent of the type of food consumed. Non-stressed rats ingesting comfort food decreased risk assessment as well. Stress and comfort food increased time spent in the center of the open field and delayed the first crossing to a new quadrant. Stress increased the plasma level of glucose and insulin, and reduced triglycerides, although consumption of comfort food increases glucose, triglyceride and leptin levels; no effect on leptin level was associated to stress. The stress induced increase in serum corticosterone was attenuated when rats had access to comfort food. It was concluded that foot-shock stress has an anorexigenic effect that is independent of leptin and prevented upon access to comfort food. Foot-shock stress also has an anxiolytic effect that is potentiated by the ingestion of comfort food and that is evidenced by both EPM and open field tests.

This article is available online at http://dmd.aspetjournals.org

No abstract

No abstract