Limitations in developing gossypol acetic acid as a male contraceptive.

Highly purified gossypol acetic acid (5 mg/day; oral) alone and in combination with potassium chloride (0.25 mg/day; oral) was tested in adult male langurs for 120 days to evaluate reversibility of its antifertility action and possible hypokalemia. The treatment resulted in severe oligospermia with impairment of sperm motility. Sperm morphological defects were evident. The functional activities of accessory sex glands and libido remained unimpaired. Occurrence of hypokalemia was found more pronounced in the gossypol alone group. Extensive renal potassium loss was evident and conversely the renal excretion of sodium decreased markedly. The activities of serum transaminases increased significantly. Other parameters of blood and of urine did not show any marked alterations. Complete reversal of the above changes was evident following 90 to 105 days of withdrawal of treatment. In conclusion, the oligospermia achieved was reversible and the hypokalemic response of langurs is similar to human and not related to impurity of the drug.