Evaluation of the ultrastructural changes in the human Sertoli cell in testicular disorders and the relationship of the changes to the levels of serum FSH

Sertoli cell ultrastructure was compared in men with testicular disorders (hypospermatogenesis; germ cell aplasia) and men with normal testes to determine if any specific cytological change could be correlated with diminished feedback from the testis resulting in elevated serum FSH levels. The normal Sertoli cell contained smooth endoplasmic reticulum, mitochondria and variable numbers of lipid inclusions, lipofuscin, crystals of Charcot-Böttcher and specialised inter-Sertoli cell junctional complexes. The principal abnormalities in Sertoli cells of men with testicular disorders were: 1) dilated vesicles of smooth endoplasmic reticulum and occasional expansions of the intercellular space; 2) increased numbers of cytoplasmic filaments; and 3) with germ cell aplasia inter-Sertoli cell junctions were complexly arranged due to interdigitation of Sertoli cell processes. Occasionally, increased lipid and lipofuscin aggregations were seen and in germ cell aplasia, aggregations of cytoplasmic glycogen were often present. Although these changes were seen more consistently with germ cell aplasia they were observed frequently with hypospermatogenesis where some tubules contained Sertoli cells with normal features. No correlation was found between abnormal Sertoli cell cytology and serum FSH levels.