The prospective study comprised 20 white outbred male rats with disturbed spermatogenesis, which was modeled by moving both testicles into the abdominal cavity for 2 weeks and then were returned into the scrotum. What is more testicular tissue from newborn rats (1-2 days after birth) was transplanted under the tunica albuginea in the trial series. In the control experiments, transplantations were not performed. Animal examination after 1 and 3 month revealed frank testicular hypotrophy (up to 51% of the norm); sharp spermatogenesis violation manifested in maturation block of spermatogenic epithelium at the level of spermatogonia or spermatocytes of the 1st order; 3-4 fold decrease in Sertoli cells and more than 10-fold decrease in Leydig cells, as well as an almost twofold decrease in the concentration of testosterone in the blood. In experiments with transplantation of neonatal testicular tissue established transplants, which size increased by 3 months, were found. Wherein a gradual increase in the mass of cryptorchid testicles up to 84% of the norm, complete recovery of spermatogenesis in most of the tubules (presence of spermatozoa in the lumen of the tubules) and normalization of the testosterone level in the blood were registered. A pronounced therapeutic effect of the neonatal testicular tissue fragments transplantation is believed to be associated with the preservation of the different organ structures’ stem cells cooperation in an optimal microenvironment (niche). Also the long-term preservation of the viability and proliferative activity of the transplanted tissue cells, which is determined by the immunopriety of the transplantation area (the presence of the hemato-testicular barrier) and the low immunogenicity of stem cells, is very important.

Authors declare lack of the possible conflicts of interests.