Artificial intra-abdominal cryptorchidism in young adult rats leads to irreversible azoospermia.

To study reversibility of artificial intra-abdominal cryptorchidism, in four groups of 5 rats at 3 months of age vasocystostomies (a microsurgical operation anastomosing both sperm ducts into the urine bladder) were carried out. This procedure enables sperm output measurements, which was performed by putting the animals for 24 h in metabolic cages. Four weeks later 15 of the remaining animals were operated again to induce artificial cryptorchidism. In a fourth group, 3 animals were sham-operated only, leaving the testes in place. Two weeks later in the animals of group I cryptorchidism was reversed by an orchiopexy operation; in group II orchiopexy was carried out after 4 weeks, in group III after 8 weeks. In group IV the animals were sham-operated again. Evaluation of sperm output took place for 3 months after orchiopexy. In the 1st week after vasocystostomy the animals showed a large variation in sperm output, but 2 weeks later, all animals had sperm output between 30-60 x 10(6) of spermatoza/24 h. Immediately after cryptorchidism sperm output decreased dramatically, and 2 weeks later all animals were azoospermic, except for sham-operated controls. After orchiopexy not one of the experimental animals showed any return of spermatozoa. We concluded that intra-abdominal cryptorchidism soon leads to irreversible damage to the testes resulting in azoospermia.