Figure 3.

Estimation of testicular volume, testicular surface area, and the length of the seminiferous tubules. (A) Estimation of testicular volume by employing the point-counting system. The volume of testicular structures was estimated by randomly superimposing a point-counting probe onto each section. The upper-right corner of each point (arrow) was used as a reference to count the number of points hitting the targeted region of interest (hematoxylin-eosin stain, scale bar: 200 µm). (B) Calculation of the surface area of seminiferous tubules using test line probes randomly superimposed onto each section. The test points hitting the seminiferous tubule epithelium (arrowhead) and the points where test lines and the seminiferous tubule lumen intersect (arrows) were counted (hematoxylin-eosin staining, scale bar: 200 µm). (C) The unbiased counting frame principle was applied to estimate the length of the seminiferous tubules. The profiles located inside the counting frame or crossing the inclusion lines (green lines) were counted (hematoxylin-eosin staining, scale bar: 200 µm).