Flow cytometric DNA analysis demonstrates contralateral testicular deterioration in experimental unilateral testicular torsion of prepubertal rats.

It has been postulated that unilateral testicular torsion causes damage to the contralateral testis and reduces fertility. However, in animal studies such an effect has not been fully proven by histopathologic examination or other conventional assays of spermatogenesis. We investigated the effect of unilateral testicular torsion on contralateral spermatogenesis in prepubertal rats using quantitative flow cytometric DNA analysis. Male rats were divided into three groups which underwent sham-operation, simple hemiorchiectomy or unilateral testicular torsion. Five weeks after these operations, fertility and spermatogenesis by flow cytometry were evaluated. No significant differences were observed in body weight, contralateral testicular weight or serum testosterone concentration among the three experimental groups. In the torsion group, mean seminiferous tubular diameter, number of foetuses, fertility rate and percentage of haploid cells were all significantly decreased compared to the other two groups. These results suggest that unilateral testicular torsion causes damage to the contralateral testis and consequently can reduce the future fertility of prepubertal rats.