Treatment with estrogen receptor agonist ERβ improves torsion-induced oxidative testis injury in rats

The purpose of the present study was to investigate the potential antioxidant, anti-apoptotic and sperm function-preserving effects of estrogen, estrogen receptor (ER)α and ERβ agonists in a rat model of testis torsion-detorsion (T/D).

Under anesthesia, 6-8-week-old male Sprague-Dawley rats underwent sham-operation or testicular torsion by fixing left testis rotated at 720° for 2 h. After detorsion, rats were treated with ERα agonist (1 mg/kg/day, subcutaneously, sc) or ERβ agonist (1 mg/kg/day, sc) or estradiol (E₂, 1 mg/kg/day, in drinking water) or vehicle on the following two days. On the third day, testicular blood-flow was recorded and then left testes were extracted for molecular and histochemical analysis.

The findings showed that reduced testicular blood-flow following torsion was partially restored on the 3rd day of detorsion, while treatments with either of the ER agonists or E₂ returned blood flow fully back to the control levels. When the testis-torsioned rats were given ERβ agonist during the detorsion period, tubular injury was lessened, sperm count and motility were increased, while the production of reactive oxygen metabolites and apoptosis in the testis tissues were totally suppressed. Although a down-regulated expression of androgen receptor (AR) along with a reduction in serum testosterone level was observed in the vehicle-treated T/D group, all three treatments up-regulated the expressions of AR and its mRNA, while ERα agonist and E₂ suppressed the testosterone level.

ERβ receptor activation during the post-ischemic period may be beneficial in protection against torsion-related oxidant testicular injury and infertility.