P-135: Protective Activity of Tacrolimus Contralateral Epididymal Sperm Fertilizing Capacity Following Unilateral Vas Deferens Obstruction: A Murine Model

Background: Auto-immunization was proposed as the mechanism of contralateral testicular damage following unilateral vas deferens injuries. The objective of this experimental in vitro study was to elucidate the effect of tacrolimus (TS) as a powerful immunosuppressant on contralateral epididymal sperm fertilizing capacity following unilateral vas deferens obstruction (UVO) in mice. Materials and Methods: Adult male mice were randomly assigned to four experimental groups. Two groups of mice were undergone to UVO under anesthesia with an intraperitoneal administration of ketamine (45 mg/kg) and xylazine (10 mg/kg). Following caudal abdominal incision, UVO was induced via left vas deferens ligation by a 4/0 silk suture 2 cm from the epididymis. One of these groups received TS (10 mg/kg per day, orally) for 5 days starting from the day of induction of experimental UVO. Corresponding control groups were also included. Contralateral epididymal sperm fertilizing capacity of all animals was evaluated following in vitro fertilization at 5 weeks postoperatively. Results: UVO resulted in significant decreases in fertilization rate and embryonic development along with increased rates of embryo arrest. TS administration noticeably attenuated all UVO-induced negative changes in the above-noted parameters. Conclusion: These findings suggest that TS therapy may have beneficial effects in UVO-induced fertility problems. However, further studies have to be contemplated to anticipate the effects of TS in human cases.