RESUMO
The review shows typical ultrastructural alterations of germ, Sertoli, and Leydig cells in infertile men. Regardless of the cause of infertility, the disruption of the spermatogenic process usually occurs in the pachytene stage of meiotic prophase and in the stages of early spermatid maturation. The disturbances affect the cytoplasm more than the nucleus, and the synaptonemal complexes have shown significant stability even in the severely injured testes. An acrosome formation is found to be open to injury in more advanced germ cells during spermatid maturation. The manner of reaction of the Sertoli cells under different pathological conditions depends on the presence and degree of maturation of the neighboring germ cells. The appearance of immature Sertoli cells is accompanied by the loss of germ cells more advanced in their differentiation. In most pathologically altered testes, mature Sertoli cells reveal a universal manner of reaction of cell organelles. Leydig cell ultrastructure fluctuates considerably, and the alterations predominantly affect the sites of steroid synthesis, in spite of disease specificity. It becomes clear that a complex estimation of a real testicular state requires the application of new techniques as well as recognition of local control mechanisms. This will provide evidence toward elucidation of male infertility.
