PERMANENT TESTICULAR DAMAGE-INDUCED LN RATS BY A SINGLE-DOSE OF TUNICAMYCIN

Tunicamycin administered as a single subcutaneous dose of 200 mu g/kg caused permanent destruction of seminiferous tubules in adult male rat s. The fertility of females was unimpaired by doses of up to 450 mu g/ kg. Degenerative changes in seminiferous tubule epithelium commenced 3 to 5 days after injection and by day 19 affected 95% of tubule profil es in sections. In 95% of tubules only Sertoli cells survived to day 5 6. Tubules without any surviving cells were present from day 19 and sl owly increased in number, a variable proportion becoming mineralised. No regeneration occurred within one year. Leydig cells became more pro minent because of the atrophy of seminiferous tubules, but their total mass did not differ significantly from that of control rats, nor did the plasma concentration of testosterone. Changes in tissues other tha n the testes were transient, The testicular damage seems to have resul ted from localised ischaemia caused by tunicamycin-induced vasoconstri ction.