Maturation of the juvenile rat testis after surgical treatment of cryptorchidism

A comparative study of the effects of non-union of testis and epididymis and cryptorchidism on testicular development and spermatogenesis in the rat

Malunion of testis and epididymis is a congenital anomaly of human undescended testicles which may be of considerable clinical importance. In an experimental model in rat the effects of early disconnection of testis and epididymis (16 days) on testicular development have been testis and puberty. The results are compared with corresponding effects of cryptorchidism and sham-operation. The testes were weighed, and the relative proportions of haploid, diploid and tetraploid cells were quantified by DNA flow cytometry. The histology was evaluated by light and electron microscopy. The non-union operated testes showed a close to normal weight development until about 40 days of age, whereafter a decline occurred. The progression of the maturation division was only slightly reduced at 30 and 37 days of age, but later the spermatogenesis was significantly inhibited. At 58 days of age the maturation division had practically ceased in non-union operated testes. In cryptorchid animals the onset and progression of maturation divisions were almost totally depressed, and only traces of haploid cells were seen in some specimens. The transient increase in tetraploid cells, reflecting primary spermatocytes seen at about 30 days during normal testicular development, was neither depressed in non-union operated nor in cryptorchid animals. This indicates that the major block in spermatogenesis in both situations is at the stage of the primary spermatocytes. At 58 days of age the testicular histology was similar in non-union operated and cryptorchid testicles with many tubular sections showing only Sertoli cells. Scattered and partly degenerated germinal cells were seen in some sections. No histological signs of increased intratubular fluid pressure were detected, suggesting that pressure atrophy is not decisive for the reduced spermatogenesis in non-union operated gonads.

Effect of simulated orchiopexy on spermatogenesis in the dog

The poor fertility after orchiopexy can be due either to the previously prolonged high abdominal temperature, to surgical trauma or to congenitally malformed or dissociated testis and epididymis. In order to test whether manipulation of the testis and the spermatic cord in juvenile dogs causes damage to the seminiferous epithelium after puberty, orchiopexy was performed stepwise in 31 normal young dogs. In four dogs, in which traction to the proper testis ligament or biopsy was carried out, a significantly lower relative testis weight was found, together with impaired differentiation of the seminiferous epithelium. From these experiments it was clear that surgical procedures in the inguinal and scrotal region do not necessarily affect the development of the seminiferous epithelium in the dog. However, trauma to the vaginal tunic seemed to be crucial, causing damage to the differentiation of the seminiferous epithelium.

Ultrastructural study of the Sertoli cell and the limiting membrane in the seminiferous tubule of the adult cryptorchid rat

Cryptorchidism was simulated in 13-15-day-old rats by severing the gubernaculum testis and fixing the testis to the abdominal wall. Ultrastructural examination of the testis was made 100 days after birth when a number of modifications to the seminiferous tubules were noted. Germ cells were scanty, with only occasional spermatogonia and primary spermatocytes persisting. The nuclei of Sertoli cells were regular and oval or indented in shape. Their cytoplasm was characterized by a rich smooth endoplasmic reticulum, lipid inclusions and mitochondria with tubulo-vesicular cristae indicative of steroïdogenic activity. The decrease in the number of the germ cells induced a membrane rearrangement with numerous tight junctions and interdigitations between the Sertoli cells. Sertoli cell-specific junctional complexes were very extensive. The lamina propria of the seminiferous tubule appeared thickened and folded and the multilayered basal lamina had complex folds. After fixation with glutaraldehyde containing lanthanum, the latter substance was identified in the basal intercellular spaces of the seminiferous tubules indicating that the blood-testis barrier remains functional in the intra-abdominal testis.