Figure 6: Effect of HPD, PEN and PEN + HPD on seminiferous tubules diameter (×40). Normal seminiferous tubule structure was observed in sham group (a) and PEN group (100 mg/kg) (b). A decrease in seminiferous tubules' diameter, germinal layer and sperm was observed in HPD group (c). Normal seminiferous tubule structure was observed in PEN + HPD (100 mg/kg) group (d). Black arrow identifies the germinal layer (reduction in epithelial height and irregularities in the structure of the margin of tubules), yellow arrow identifies the destruction of the membrane seminiferous tubules structure and blue arrows identify sperms. PEN: Pentoxifylline, HPD: High-protein diet.