Figure 4.

Mean and standard error of stereological indices of seminiferous tubules in 2.5, 5 and 10 mg/kg groups in comparison with controls after 40 days of TiO ${}_2$ NP exposure. A) Lumen diameter (μm), B) Luminal area (μm²), C) Cellular diameter (μm), D) Cellular area (μm²), E) Total diameters (μm), F) Cross-sectional area of the tubule (μm²), G) Number of seminiferous tubules per unit area of testis, H) Numerical density of the seminiferous tubules. *P $<$ 0.05, **P $<$ 0.01.