Histopathological sections of Peyer’s patches from male Wistar rats of the Control - CT (A, B, C and D), Bisphenol A - BPA (E, F, G and H), Bisphenol A + Selenium - BPA + Se (I, J, K, L) and Selenium - SE (M, N, O, P) groups. The CT group showed normal structure, with simple cylindrical epithelium, with the presence of intraepithelial lymphocytes (circle) and lymphocytes in the follicular region (C and D). The BPA group showed tissue alterations in the epithelial layer where apoptotic processes (arrow), presence of vacuoles (*) and immune cells (arrowhead) (G – H) were observed. The BPA + Se group did not present changes in the epithelial layer, but in the follicular region there was the presence of vacuoles (*) and high cellular activity. The Se group presented an architecture similar to the CT group. Scale bars: A – C, E – G, I -K, M and O – 100x magnification; B – D, F – H, J – L, N and P – 400x magnification.
However, a disorganization of the epithelial layer of the BPA group was observed (Figure 2E), presenting a discontinuity of the same, and morphological changes in the goblet cells suggesting that this contaminant led to apoptotic processes in the epithelial layer, impairing repairs in the epithelial layer (Figure 2F). In the BPA+Se and Se groups (Figure 2 I-M), the epithelial layer was preserved when compared to the CT group (Figure 2 A-B).
It was found that there was a structural disarrangement in the architecture of the follicular region of the BPA and BPA+Se groups, where there are areas of inflammation, especially the basal region of the Peyer’s patches with the presence of vacuoles in its structure (Figure 2G). It was noted that inflammation was less pronounced in the BPA+Se group when compared to the BPA group, which shows an antioxidant and anti-inflammatory activity of Se under tissue exposed to BPA.
The immunohistochemical evaluation of the cell markers revealed that there was a reduction in the cell proliferation process in the BPA group when compared to the other groups. In addition, there was an intense Ki-67 staining in the BPA+Se group, when compared to the other groups (Figure 3). However, there was no marking in the groups submitted to BCL-2 reaction (Figure 4).
Figure 3. Photomicrograph of Peyer’s patches of Wistar rats of CT, BPA, BPA+Se and Se groups labeled with Ki-67.