Effect of 4-chloromethyl-2-methyl-2-pentyl- 1,3-dioxolane (AY-22,352) on the fertilizing ability of hamster epididymal spermatozoa.

Fertile male hamsters were injected subcutaneously with AY-22,352 to determine the minimal antifertility dose, the site of action and the onset and duration of infertility. Fertility tests showed that 37 mg AY-22,352/kg/day induced sterility within 4 days. None of the males became infertile within the first 2 days but marked loss of sperm fertilizing ability had occurred by 24 hr from the second injection; all males were sterile after the fourth dose. Comparable daily treatment procuded the same antifertility effect subsequent to bilateral ligation of the corpus epididymidis and fertilization did not occur after artificial insemination with spermatozoa from the cauda epididymidis of such animals. The prompt recovery of fertilizing ability of spermatozoa in males which receoved four daily doses of AY-22,352 (37 mg/kg) and had ligated ductuli efferentes shows that transport of epididymal spermatozoa and their acquisition of fertilizing ability are not influenced by the drug.