Effects of in utero and lactational exposure to bisphenol A on bone tissue in rats

Bisphenol A (BPA) is an industrial chemical that is used in the production of polycarbonate plastics and epoxy resins. The applications result in consumer exposure to BPA via the diet.The toxicity and hormonal activity of BPA in laboratory animals have been studied and hormone related cancers and metabolic disorders have been observed in rodents. The objective of this project was to study effects on bone tissues of rats exposed to low doses of BPA in utero and during lactation. 110 pregnant Wistar rats were randomly distributed into five groups and gavaged with (0, 0.025, 0.25, 5 or 50 mg BPA/kg body weight (b.w.)/day) from gestation day 7 until weaning at pup day 22, offspring were exposed in utero and during lactation. Body weights of the offspring were recorded and right femurs were collected for geometry and densitometry measurements using peripheral quantitative computed tomography and also for analysis of biomechanical properties via three-point bending. The major findings of the study: Increased femur length in female offspring of dams exposed to 0.025 mg BPA/kg b.w./day or 5 mg BPA/kg b.w./day; Increased cortical thickness of male offspring of dams exposed to 0.025 mg BPA/kg b.w./day. No effects of biomechanical properties were seen on the bones of either sex offspring. In conclusion, this study demonstrates that in utero and lactational exposure to BPA at levels relevant to current human exposure alters femoral geometry in rat offspring. BPA showed endocrine disruptive effects on both female and male offspring bone tissue. The mechanisms behind these differences are unknown