Evaluation of contralateral testicular damage after unilateral testicular torsion by serum inhibin B levels

Abstract

Background/purpose: It is still controversial whether unilateral testicular torsion (TT) affects contralateral testis. The authors wanted to evaluate contralateral testicular damage in a rat model by the serum inhibin B levels, which is suggested as a marker of Sertoli cell function and spermatogenesis.

Methods: Fifty peripubertal male Wistar Albino rats were divided into 5 groups each containing 10 rats. Surgery was conducted under intraperitoneal 1-shot ketamine (50 mg/kg) anesthesia. Torsion-detorsion, torsion-detorsion-orchiectomies, orchiectomies, and sham operations were performed on the right testicle through a midline incision. Torsions were created by rotating the right testes 720 degrees in a clockwise direction and maintained by fixing the testes to the scrotum with a silk suture. Torsion duration was 4 hours. After each surgical intervention the incisions were closed. In group 1, 3-mL blood samples were taken to determine basal values of inhibin B in serum, and bilateral orchiectomies were performed. In group 2, 4 hours of torsion and detorsion was created and 1 month later, 3-mL blood samples were taken, and bilateral orchiectomies were performed. In group 3, 4 hours of torsion-4 hours of detorsion was created, and right orchiectomies were performed and 1 month later, 3-mL blood samples were taken and contralateral orchiectomies were added. In group 4, unilateral orchiectomies were performed, and 1 month later, 3-mL blood samples were taken, and contralateral orchiectomies were added. After the measurement of the serum inhibin B levels and histopathologic examinations, results are expressed as mean +/- SD.

Results: Serum inhibin B levels expressed as mean +/- SD were 108.233 +/- 21.296 pg/mL for group 1, 54.065 +/- 16.910 pg/mL for group 2, 74.195 +/- 2.779 pg/mL for group 3, 108.335 +/- 26.078 pg/mL for group 4, and 107.645 +/- 4.705 pg/mL for group 5. Inhibin B levels in group 2 and group 3 were different from group 1, group 4, and group 5 (P <.05). In histologic examination, Johnsen's scores expressed as mean +/- SD of right testes were 9.74 +/- 0.08 for group 1, 3.64 +/- 3.36 for group 2, and 9.86 +/- 0.05 for group 5. Histologic findings in group 2 were different from group 1 and group 5 (P <.05). Johnsen's scores expressed as mean +/- SD of left testes were 9.78 +/- 0.09 for group 1, 9.75 +/- 0.14 for group 2, 9.76 +/- 0.15 for group 3, 9.79 +/- 0.07 for group 4, and 9.82 +/- 0.08 for group 5, and there was no difference between groups (P >.05).

Conclusions: The serum inhibin B levels decrease after unilateral TT reflecting contralateral testicular damage. Orchiectomy to prevent contralateral testicular damage after TT may not be effective after critical period. Measurement of inhibin B levels to evaluate contralateral testicular damage after unilateral TT is more effective than histopathologic examination.