Sertoli cell nuclear changes in human testicular biopsies as revealed by three dimensional reconstruction

Summary. Serial semithin sections of human testicular biopsy material were used for three-dimensional reconstruction in order to obtain information about Sertoli cell nuclei in normal and pathologically altered seminiferous epithelia. The three dimensional reconstruction program is based on the triangulation of image point series. It includes a calculation modus for determining surfaces and an approximation formula for the estimation of volumes. Nuclei from the following specimens were reconstructed and for each the volume (v), surface (s), and a quotient (v/s), which is regarded as a marker for the degree of membrane infoldings, were calculated as follows: (1) For normal spermatogenesis (stage 1, 2, 3, 5; n=18) v = 409.7 ± 33.0 μm3, s = 429.6±40.5 μm2, v/s = 0.96 ± 0.05. The values revealed no stage-specific differences; (2) for hypospermatogenesis (n=9) v = 493.7 ± 33.7 μm3, s = 462.6 ± 51.4 μm2, v/s = 1.07 ± 0.085; (3) for spermatogenic arrest at the level of primary spermatocytes (n = 4) v = 537.8 ± 49.5 μm3, s = 424.4 ± 28.7 μm2, v/s = 1.27 ± 0.052; (4) for spermatogenic arrest at the level of spermatogonia (n = 17) v = 472.4 ± 110.3 μm3, s = 397.8 ± 64.2 μm2, v/s = 1.18 ± 0.106; (5) for Sertoli-Cell Only Syndrome (n=14) v = 438.7 ± 42.6 μm3, s = 345.1 ± 38.0 μm2, v/s = 1.28 ± 0.087; (6) for hypoplastic tubules in a biopsy showing mixed atrophy (n=19) v = 275.6 ± 53.2 μm3, s = 228.8 ± 26.0 μm2, v/s=1.20±0.115; (7) for ovot-estis (46xx, 47xxy) (n=14) v = 417.3±71.2 μm3, s = 317.2±26.3 μm2, v/s= 1.31±0.13 and (8) for carcinoma in situ (n=25) v = 436.3±83.1 μm3, s = 338.2±64.4 μm2, v/s = 1.30±0.08. A significant increase of nuclear volume was found in Sertoli cells of all specimens showing different types of spermatogenic impairment (maturation arrest, hypospermatogenesis) and a significant decrease in Sertoli-cell nuclei from hypoplastic tubules. Compared to normal, v/s was significantly increased in all specimens showing pathological alterations suggesting that developmental and/or functional Sertoli cell defects seem to be constantly associated with spermatogenic impairment.