Characterization of breathing following four weeks of prolonged dietary Bisphenol A exposure in mice

Abstract

Bisphenol A (BPA) is a chemical used in the production of various plastics. It is classified as an endocrine disruptor since it can exert estrogen‐like effects in the body. Although estrogen can play a role in the control of breathing, it is unknown if BPA influences conscious ventilation. We tested the hypothesis that 4 weeks of dietary BPA administration would result in an altered pattern of breathing compared to the response of dietary controls. At 8 weeks of age, male CD‐1 mice were housed in polypropylene cages and administered a soybean oil‐free diet (AIN‐93G) for 2 weeks. At 10 weeks of age the mice were placed onto control (C: AIN‐93G; n=4), C+ethinyl estradiol (EE: 0.1 ppb; n=5) or C+BPA (50 mg BPA/kg diet; n=5) diets. Unrestrained barometric plethysmography was used to quantify frequency (F; breaths/min), tidal volume (TV; mL/breath), and minute ventilation (MV; mL/min) in 14 week old mice during exposure to room air (MEAN±SEM). Control mice displayed similar F (C: 150±28 vs. C+BPA: 129±11 vs. C+EE: 150±25), TV (C: 0.35±0.01 vs. C+BPA: 0.49±0.05 vs. C+EE: 0.48±0.07) and MV (C: 54.4±9.5 vs. C+BPA: 62.5±10.3 vs. C+EE: 69.8±9.6). These preliminary findings indicate no difference in quiet breathing following 4 weeks of dietary BPA or EE administration in mice. Supported by LMC start‐up funds (LRD) and the Hill Collaboration on Environmental Medicine (KCD).