Andrologia. 2020;00:e13817. wileyonlinelibrary.com/journal/and | 1 of 7 https://doi.org/10.1111/and.13817 © 2020 Wiley-VCH GmbH 1 | INTRODUCTION Azoospermia, whether obstructive (OA) or nonobstructive (NOA), is a challenging condition affecting 10%–15% of infertile males (Chan & Schlegel, 2000). With the evolution of intracytoplasmic sperm in- jection (ICSI), certain subtypes of azoospermia have become treat- able, where spermatozoa are retrieved from testes in the so-called surgical sperm retrieval techniques (SSR) (Schlegel, 2009; Wosnitzer & Goldstein, 2014). Another breakthrough for azoospermia has been the ability to successfully cryopreserve the retrieved spermato- zoa for use in ICSI (Miyaoka, Orosz, Achermann, & Esteves, 2018). However, whether the procedure of cryopreservation for surgically retrieved testicular spermatozoa can induce further stress, such as oxidative stress (OS), remains an open research question. Cryopreservation can be injurious for spermatozoa due to ice crystal formation and induction of OS through the release of re- active oxygen species (ROS) (Aisen, Quintana, Medina, Morello, & Venturino, 2005). Spermatozoa can be affected by ROS hazardously through its damaging effects on sperm membrane lipids, mitochon- drial function and DNA integrity. Infertile men with defective sper- matogenesis, as in NOA, were found to have inherent metabolic stresses and higher levels of testicular oxidative stress (Rahbar Received: 5 April 2020 | Revised: 25 July 2020 | Accepted: 29 July 2020 DOI: 10.1111/and.13817 ORIGINAL ARTICLE Testicular tissue oxidative stress in azoospermic patients: Effect of cryopreservation Alaa E. Moubasher 1 | Emad A. Taha 1 | Aya Younis 1 | Mickel E. Fakhry 2 | Hanan Morsy 1 1 Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Assiut University, Assiut, Egypt 2 Department of Biochemistry, Faculty of Medicine, Assiut University, Assiut, Egypt Correspondence Hanan Morsy, Dermatology and Venereology, Assiut University, Assiut, Egypt. Email: hanan_morsy2003@yahoo.com Abstract This study evaluated oxidative stress (OS) in human testicular tissue in obstruc- tive (OA) and nonobstructive azoospermia (NOA) before and after cryopreserva- tion. 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 spermato- zoa. 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 com- pared to OA. The extent of OS correlated negatively with spermatogenesis grade. Testicular tissue of patients with OA seems to withstand OS induced by cryopreser- vation more than NOA. KEYWORDS Azoospermia, catalase and malondialdehyde, cryopreservation, oxidative stress, testicular spermatozoa