Testicular tissue oxidative stress in azoospermic patients: Effect of cryopreservation

This study evaluated oxidative stress (OS) in human testicular tissue in obstructive (OA) and nonobstructive azoospermia (NOA) before and after cryopreservation. Azoospermic patients were subjected to surgical sperm retrieval (SSR) and cryopreservation. Assay of catalase activity (CAT) and malondialdehyde level (MDA) using colorimetric methods was done. The number of retrieved spermatozoa and the Johnson score were assessed in fresh testicular samples. The study included 21 OA (group A) and 16 positive sperm retrieval (group B, positive NOA). The basal CAT activity in the positive NOA group was significantly higher than that in the OA group. Basal MDA level was also significantly higher in NOA than in OA group. CAT activity and MDA level correlated negatively with the mean number of retrieved spermatozoa. After cryopreservation, there was a significant increase in CAT activity in OA, while there was no significant difference in MDA level in both OA and positive NOA. We concluded that patients with NOA seem to have increased testicular OS compared to OA. The extent of OS correlated negatively with spermatogenesis grade. Testicular tissue of patients with OA seems to withstand OS induced by cryopreservation more than NOA.