Effects of a single ethanol injection into the vas deferens on the testicular function of rats.

1. A new approach to rapid male sterilization has been studied by giving a single injection of 95% ethanol directly into the vas deferens. It produced an effective block in the lumen. The mating exposure test showed that the males were sterile. The sperm granulomas at the site of vas injection were confirmed. 2. Ethanol injection in the vas deferens caused an atrophy of the testes. Extensive necrosis and exfoliation of the seminiferous elements were conspicuous. 3. Decrease in testicular weight, seminiferous tubule diameter and RNA and sialic acid levels after 4 weeks of vas injection were associated with the histological evidence for severe degeneration of spermatogenic elements. The protein contents of testis, epididymides and seminal vesicles did not change. 4. Testicular cholesterol, total lipids and alkaline phosphatase activity was increased. 5. Low sialic acid levels in the testis, epididymides and seminal vesicles of vas-injected rats indicated an inhibition of androgen production, which was further reflected in reduced nuclear diameters of leydig cells.