Effect of allopurinol and oxypurinol treatment on apoptosis in experimental testicular torsion model

Aim: Testicular torsion is a urological emergency that can cause testicular loss. Reperfusion damage that develops after surgical detorsion may cause further tissue damage, resulting in loss of testicular function and infertility. Effective treatment after testicular torsion can protect against the dangerous effects of ischemia-reperfusion. The aim of this study is to investigate the effects of allopurinol and oxypurinol treatment on oxidative stress and apoptosis in an experimental testicular torsion model. Materials and Methods: Thirty-two rats were divided into 4 groups: Group 1 (Sham-surgery, n=8), testicle was exposed but no torsion was performed; Group-2 (IR+SF, n=8), torsion/detorsion was applied to the left testicle and 1 ml SF was administered; Group-3 (IR+Allopurinol, n=8), torsion/detorsion was applied to the left testicle and 50 mg/kg allopurinol was administered; Group 4 (IR+Oxypurinol, n=8), torsion/detorsion was applied to the left testicle and 50 mg/kg oxypurinol was given. The left testicle sample was taken on the 28th postoperative day and TAS, TOS and OSI levels were measured in the tissue; Additionally, Bax, Bcl-2, eNOS and VEGF-A gene expression levels were examined. Results: While allopurinol and oxypurinol treatment significantly increased TAS and TOS levels compared to the IR-SF group, it significantly decreased OSI levels (p<0.001). Oxypurinol was found to be significantly more effective in reducing oxidative stress (p<0.001). Allopurinol and oxypurinol treatment significantly reduced the Bax gene expression level compared to the IR+SF group (p<0.001). Allopurinol (p=0.009) and oxypurinol (p=0.001) treatment significantly increased Bcl-2 level compared to the IR+SF group. Allopurinol and oxypurinol treatment significantly reduced the apoptosis index compared to the IR+SF group (p<0.001). Allopurinol (p=0.007) and oxypurinol (p<0.001) treatment significantly increased the eNOS gene expression level compared to the IR+SF group. Allopurinol and oxypurinol treatment significantly increased the VEGF-A gene expression level compared to the IR+SF group (p<0.001). Conclusion: Allopurinol and oxypurinol have effects on reducing oxidative stress in the testis after IR, and oxypurinol has a greater antioxidant effect. Allopurinol and oxypurinol treatment have effects that reduce apoptosis by contributing positively to the eNOS and VEGF-A mediated repair process in testicular tissue after IR. In these respects, allopurinol and oxypurinol are potential agents for clinical applications in testicular torsion.