Fig. 6

Light photomicrographs of transverse sections, 5 μm in thickness and stained with H&E, through the Ruditapes decussatus digestive glands showing histopathological alterations in the digestive gland structure after exposure to different concentrations of bisphenol A (BPA) for 21 days in comparing with the normal structure of a control group. (A) Digestive glands of the control group showing normal structure with digestive tubules that are composed of a single layer of digestive (white wide arrow) and basophilic (black wide arrow) epithelial cells surrounding a narrow tubular lumen and normal intertubular connective tissue connecting these tubules, (B) Digestive glands subjected to 1 µg/L of BPA showing fused and atrophied digestive tubules represented by a diminution in the thickness of the epithelial cell layer and widening of the tubular lumen, and (C-D) Digestive glands subjected to 5 µg/L of BPA showing necrotic tubules, necrotic intertubular connective tissue, and the presence of lipofuscin pigment (black arrowhead). (dt) digestive tubule, (ec) epithelial cells, (tl) tubule lumen, (it) intertubular tissue, (ft) fused tubules, (at) atrophied tubules, (nt) necrotic tubules, and (ni) necrotic intertubular tissue