Return to fertility, toxicology, and transgenerational impact of treatment with WIN 18,446, a potential male contraceptive, in mice.

ABSTRACT

OBJECTIVES: We examined the return to fertility and transgenerational impact of treatment with WIN 18,446, an experimental male contraceptive, in mice. STUDY DESIGN: We paired male mice treated with WIN 18,446 for 4 weeks to suppress spermatogenesis, followed by a 9-week recovery, and mated them with normal females to assess fertility. F1 generation mice were subsequently mated to ascertain any transgenerational impact of treatment on fertility. Testes were examined histologically. RESULTS: WIN 18,446-treated mice and their progeny produced normally sized litters (6.5 pups per litter after treatment and 7.3 pups per litter from the progeny). However, testes histology revealed rare residual intratesticular foci of mineralization after treatment. CONCLUSIONS: Fertility normalizes after WIN 18,446 treatment, and progeny also have normal fertility.