Introduction: The present work aims to examine the possible role of stem cells on biochemical markers and histopathological alterations of hypoxia caused by sodium nitrite (NaNO2) toxicity in testes of male rats.
Methods: In this study, 96 adult male albino rats were divided into 6 groups (16 rats each). Group 1 (G1) was the control group and received distilled H2O. Group 2 (G2) received daily NaNO2 (35 m/kg bwt/ day) via subcutaneous injection for 3 weeks. Group 3 (G3) received NaNO2 for 2 weeks and were then injected once with 2*106 mesenchymal stem cells (MSCs) intravenously and sacrificed 4 weeks later. Group 4 (G4) received NaNO2 for 2 weeks and were then injected with 2*106 MSCs followed by daily NaNO2 injection for 1 week; rats in G4 were sacrificed 4 weeks from MSCs treatment. Group 5 (G5) rats were treated with NaNO2 for 2 weeks and then left to recover for 4 weeks. Finally, Group 6 (G6) rats were treated with NaNO2 for 3 weeks and left to recover for 3 weeks, after which point they were sacrificed.
Results: The results showed that NaNO2 caused oxidative damage and histopathological alterations in the rat testes, as well as increased the levels of testes malondialdehyde (MDA), nitric oxide (NO) and DNA fragmentation percentage (DNA F %). Moreover, NaNO2 decreased the elevated activities of testes catalase (CAT) and total antioxidant activity (TAA), in comparison to the control group. The histological results illustrated different distortions, vacuolization and lipid accumulations in interlobular space as well as diminution of inter cellular germ cell layers, absence of Leydig cells, irregular basement membrane of tubule, and separation within spermatogenic cells. In addition, congestion and dilation of intertubular and peripheral blood capillaries were found. Nevertheless, the administration of stem cells reduced the danger actions of sodium nitrite by enhancing biochemical marker concentration.
Conclusion: There was an improvement in the histology of the rat testes, including a relatively normal order in the different stages of spermatogonia and loss of different stages of spermatocytes. Regarding the recovery period, there was also a significant improvement in each of the biochemical parameters assessed and in the histological lesions.
Key words: Sodium nitrite, hypoxia, stem cell, testes oxidative stress, testes histology