Effects of oral administration of sodium nitrite on laminin expression in mice testicular interstitium: An immunohistochemical study

Background and objective: Nitrite is one of the most common environmental contaminants affecting Extracellular Matrix (ECM) proteins expression. Drinking water contains different concentrations of nitrite and nitrate. Therefore, consumption of water contaminated with sodium nitrite can lead to infertility. This study aims to investigate the effects of oral administration of sodium nitrite on expression of laminin α5 in extracellular matrix of mice testicular interestitium using an Immunohistochemical (IHC) assessment. Methods: Eighteen fertile male mice were divided into three groups: one control group and two treatment groups I and II. Treatment I and II groups received water containing 3 and 50 mg/L of sodium nitrite, respectively during two months. Following the sacrificing, the right and left testicle of each animal were extracted for real time PCR and immunohistochemical assessment, respectively. Results: One-way ANOVA showed a significant difference in the laminin α5 content between the control and treatment II group. In the treatment I group, the average laminin was 0.97 fold and in the treatment II group its mean was 0.85 fold. The reduction in the amount of laminin in treatment II group was significant compared to the control group (P=0.003). The IHC tests showed that the ECM of the mice testicular interstitial tissue showed reaction to anti-laminin-α5 antibody. The intensity of the reaction in the control group and treatment I group was very weak to moderate, while the treatment II group showed weak to severe intensity. Kruskal Wallis test showed no significant difference in laminin α5 expression in the ECM of the interstitial spaces of seminiferous tubules between the groups. Conclusion: High concentration of sodium nitrate did not change the laminin α5 expression in the ECM of the testicular interstitial tissue.