author(s)
Ibtisam kh Abd Ali, Khalid K Kadhim and Anam R Al-salihi

abstract
The morphological changes caused by cryopreservation of the testicular tissues with different cryoprotectants have been assessed here. Testes of thirty immature male rats divided into equal five groups; Group (A) as control fresh sample, group (B) with freezing media only. Different freezing protocol were used for other groups; group (C) dimethylsulphoxide (DMSO); group (D) Glycerol and group (E) propanediol (PROH). Light and transmission electron microscope in addition to the Immunohistochemical analysis were carried out. The light and ultrastructure microscopic results showed normal testicular structures were seen in the fresh control group (A), while group (B) showed severe cryoinjury. The severest changes were for propanediol group followed by the glycerol group while DMSO group showed lighter changes. These changes were represented by discontinuity of the cytoplasmic membrane, swelling of the mitochondria and vaculation of the cytoplasm, abnormal nuclei shape with interrupted nuclear membrane and mild clumped chromatin. The results of the DNA fragmentation test revealed the lowest rate of tissue damage in the group (A) and group (C) compared to group (D and E). In conclusion, cryopreservation of immature rat testes by DMSO gave minimum structural alterations of tissue compare with Glycerol and propanediol that did not enhance DNA integrity.