Reversible changes in the testes and epididymides of dog treated with alpha-chlorohydrin.

1. Chronic administration of alpha-chlorohydrin (8 mg/kg body wt for 30 days) caused lesions in the testis of dog. The changes in the germ cells were degenerative. The seminiferous tubule and Leydig cell nuclear diameter were reduced. 2. Epididymal cell height was greatly reduced and the stereocilia had disappeared completely. The lumen was devoid of spermatozoa. 3. Alpha-chlorohydrin administration inhibited the RNA and sialic acid contents in the testes and epididymides of dog. Total cholesterol and lipids/g of testes were increased significantly after alpha-chlorohydrin administration. 4. These effects were reversible. Repopulation of testis tubules occurred following a period of 100 days recovery in dog. Numerous spermatogonia and sperm develop and traverse the epididymides. The RNA, sialic acid, cholesterol and total lipids of testes and epididymides returned to subnormal levels. 5. The possibility of using alpha-chlorohydrin as male contraception is indicated.