Fig. 7
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-B) 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, (C-D) Digestive glands subjected to 1 µg/L of BPA showing atrophied digestive tubules, represented by a diminution in the thickness of the epithelial cell layer and widening of the tubular lumen, hemocyte infiltration around the damaged digestive gland tubules, fibrosis in the intertubular connective tissue, and tubular vacuolation with disorganization of the lining epithelium, and (E-J) Digestive glands subjected to 5 µg/L of BPA showing atrophied and necrotic tubules and necrotic intertubular connective tissue with heavy hemocyte infiltration, especially granulocytes, tubular vacuolation, and the presence of brown cells associated with lipofuscin-like pigments (black arrowhead). (dt) digestive tubule, (ec) epithelial cells, (tl) tubule lumen, (it) intertubular tissue, (at) atrophied tubules, (hi) hemocyte infiltration, (f) fibrosis, (v) vacuoles, (nt) necrotic tubules, and (ni) necrotic intertubular tissue