RELATIONSHIP BETWEEN TESTICULAR MORPHOLOGY AND SPERM PRODUCTION FOLLOWING ISCHEMIA IN THE RAM

Arteriosclerosis was induced in the internal spermatic artery of rams to determine if this condition is implicated in the aetiology of testi cular pathology which causes male infertility. Data were collected on sperm concentration and motility for 56 days following surgery to prov ide an index of testicular function. Testes were then weighed and a te sticular biopsy score count was performed on histological sections to assess spermatogenic potential of seminiferous tubules. Vascular distu rbance caused focal damage of the seminiferous epithelium, similar to that seen among infertile men, and a reduction in ejaculate volume, sp erm concentration and sperm motility. Sperm concentration decreased fo llowing ischaemia yet was maintained to some degree by a germ-cell dep leted spermatogenic epithelium. Normal testicular morphology was maint ained above a testis weight of about 120 g (for an individual testis), but below this threshold spermatogenesis was severely impaired. In co nclusion, these data have provided information on the relationship bet ween testicular morphology and function following ischaemia in the ram . Furthermore, the morphological changes induced in the testis were si milar to those seen among infertile men and, by their focal nature, co uld explain the distinction between oligozoospermia and azoospermia in men exhibiting spermatogenic arrest.