Different associations of cryoprotectants for testicular tissue of prepubertal cats submitted to vitrification.

The cryopreservation of testicular tissue is presented as the only alternative for the preservation of genetic material from prepubertal animals. However, this biotechnology is still being tested. The objective of this study was to evaluate the effect of different associations of cryoprotectants and the potential of cell proliferation after vitrification of testicular tissue of prepubertal cats. Five testicular pairs from five prepubertal cats were used, and each pair was divided into four fragments. Of these, one fragment composed of the control group (CG) and the rest were distributed in experimental groups according to the associations of cryoprotectants to be tested (dimethyl sulphoxide (DMSO)/glycerol (GLY); ethylene glycol (EG)/GLY) or DMSO/EG) in a final cryoprotectant concentration of 5.6 m. The fragments were submitted to vitrification, and after one week, fragments were heated and processed for histomorphological evaluation and quantification of nucleolar organizer regions (NORs). DMSO/GLY did not differ from CG and was superior to the other vitrified groups, as to cell separation and degree of shrinkage of the basal membrane. Concerning cell differentiation, visibility of the nucleus and nuclear condensation, all the vitrified groups were inferior to CG; however, DMSO/EG was inferior to DMSO/GLY and EG/GLY, which did not differ among themselves. CG was superior to all groups in quantification of NORs. DMSO/EG was inferior to all others, and there was no difference between DMSO/GLY and EG/GLY. The association DMSO/GLY presented the best preservation of tissue integrity and potential of cell proliferation after vitrification of the testicular tissue of prepubertal cats.