Permanent changes in the functional development of accessory sex organs and in fertility in male mice after neonatal exposure to cyproterone acetate.

Abstract

Male mice were injected daily with cyproterone acetate for 10 consecutive days during one of the four following periods: 1-10 days, 11-20 days, 21-30 days or 31-40 days. At all stages studied cyproterone acetate caused a significant reduction in the relative weights of epididymis, vas deferens, preputial gland and seminal vesicle in males killed 24 h after the last injection; the androgen content (testosterone + dihydrotestosterone) of the accessory sex organs was also reduced but the differences were not always significant. Cyproterone acetate treatment from 1 to 10 days resulted in a definitive reduction in the relative weights of all accessory sex organs studied and when injected from 11 to 20 days in epididymis and vas deferens. When cyproterone acetate was injected after 20 days of age, the inhibition of sexual organ weights was reversible and at adulthood organs were normally developed. Cyproterone acetate treatment induced a high percentage of infertile males only when injected from 1 to 10 days. Spermatogenesis, androgen levels in plasma and accessory sex organs, and sexual behaviour were not affected in sterile males. These results suggest that the functional development of accessory sex organs can be permanently affected by short-term neonatal exposure to endogenous androgens.