Studies On The Optimal Regiments And Mechanisms Of Combined Administration Of Low-dose Gossypol And Steroid Hormone On Male Antifertility

Up to now, there is no an ideal approach available in clinical practices for male contraception. The antifertility efficacy of gossypol provides new clues to non-steroid hormone male contraceptive. However, a few hypokalemia or irreversible productive damage cases could be caused by treatment with a high-dose gossypol. A low-dose gossypol acetic acid (GA) regimen (10, 12.5 or 15mg/d) could induce infertility in the majority of subjects without developing hypokalemia or irreversibility, whereas the delay in onset of infertility (> 6 months) or irreversibility occurred within a year of stopping the drug in minority of subjects makes them impractical. Also, combinations of androgens and progestins would be promising candidates for male contraception. However, the unacceptable administration mode and the side effects induced by these hormonal regimens greatly limited their practicability. Our preliminary experiment suggested that a combined administration of 12mg/d dose of GA with steroids induced infertility within 6 weeks in rats, and the infertility could be maintained by a same low dose of GA alone. However, Methyltestosterone used in the experiment is hepatotoxic, and the dose of ethinyl estradiol (100 μg/kg) is too high for men as well as the number of experimental animal is too small. The comparison of the antifertility efficacy was not performed between combined administration of low-dose GA with steroid, separately administration of low-dose GA or...