Ultrastructural, fertility, and spermicidal studies with isomers and derivatives of gossypol in male hamsters.

The effects of fourteen new, orally administered synthetic analogs of gossypol on testicular ultrastructure and fertility in hamsters and the spermicidal properties of these compounds, as well as of the optical isomers of gossypol against hamster and human sperm in vitro, are reported in this study. Test compounds were administered to adult male hamsters by daily gavage for 9 weeks at doses ranging from 15 to 50 mg/kg. The results of this study have demonstrated that the fourteen new gossypol analogs evaluated herein are not effective as male antifertility agents and their in vitro activity or lack of activity as spermicides is unrelated to their in vivo contraceptive potential. In addition, the results of the study suggest that (1) the isopropyl moiety of the gossypol molecule, like the aldehyde group, is essential for its mechanism of action and (2) the pathognomonic defect in the mitochondrial sheath induced by gossypol appears to be related to its unique activity as a male antifertility agent. The significance of these findings is discussed.