Do experimentally induced ipsilateral testicular torsion, vas deferens obstruction, intra-abdominal testis or venous obstruction damage the contralateral testis through a common mechanism?

Objective. To evaluate if various conditions affecting the ipsilateral testis which also damage the contralateral testis share a common pathway for their effects. Materials and methods. The study comprised five groups of 10 adult rats which underwent surgery to produce (on their left sides); group 1, a sham operation (control); group 2, testicular torsion; group 3, vas deferens obstruction; group 4, an intra-abdominal testis; and group 5, venous obstruction. The ipsilateral and contralateral testes were harvested 4 weeks after surgery. The relative proportions of haploid cells, the mean seminiferous tubular diameter (MSTD), mean testicular biopsy scores (MTBS), and lactate and hypoxanthine levels were determined and compared. Results. The proportions of haploid cells in the ipsilateral and the contralateral testes of groups 2-5 were significantly lower than those of the corresponding testes of the control group. The MSTD and MTBS of the ipsilateral testes in groups 2-5 were also significantly lower than the ipsilateral testes of controls and the contralateral testes within the same groups. While the MSTD and MTBS of the contralateral testes of groups 1 and 5 were not significantly different, those of the contralateral testes of groups 2-4 were significantly less than that of group 1. The lactic acid and hypoxanthine levels of the ipsilateral and contralateral testes were significantly increased in groups 2 and 3. While only the hypoxanthine level of group 5 increased significantly, both variables were not significantly different between the ipsilateral testes of groups 1 and 4. Conclusions. These four treatments damaged both the ipsilateral and contralateral testes. As the lactic acid and hypoxanthine levels within the contralateral testis were greater than in the controls, testicular torsion and vas deferens obstruction seem to share a common pathway (which may be a reflex decrease in contralateral testicular blood flow) for their effects on the contralateral testis.