Immunohistochemical Detection of MHC Class II in Paraffin Embedded Rat Spleen and Mouse Brain from Animals Exposed to Bisphenol A

Bisphenol A (BPA) is an industrial chemical that functions as an estrogen disrupter. This study measured the increase of MHC II levels in the spleen (rat) and brain (mouse) of  rodents that had been exposed to BPA perinatally. Pregnant animals (female therefore) were dosed with BPA during the pregnancy. After they gave birth, the pups (female and male) were dosed directly with BPA. The animals were then weaned and sacrificed, and the tissues were collected and fixed. Spleens and brains were then embedded in paraffin. They were then stained for MHC class II using immunohistochemistry. Our results showed that after exposure to BPA, MHC II levels in female rat spleens were significantly higher than in the male spleens, and that BPA treatment alleviated this gender effect.