Effects of DEHP (500 mg/kg BW/day) and Flu on histopathological changes in immature male rats exposed to EDs from PND 21 to PND 35. Testis tissues were fixed in Bouin's solution and immersed in neutral formalin solution. The fixed tissues were embedded in paraffin, sectioned at 5 μm and mounted on slides. These sections were stained with hematoxylin and eosin (i.e., HE) and histopathological changes were assessed under a light microscope. Hyperplasia of Leydig cells, germ cell (a: stained signals), stratification of germ cells (b: stained signals), dilatation of the tubular lumen and stratification (c: stained signals), degeneration of Leydig cells (d: stained signals), and disorder of germ cells (e: stained signals) were observed in the testes of immature male rats. Results are shown at a 100 × magnification (i.e., bar = 200 μm), a 200 × magnification (i.e., bar = 100 μm) and a 400 × magnification (i.e., bar = 50 μm).