Coutinho E M, Athayde C, Atta G, Gu Z P, Chen Z W, Sang G W, Emuveyan E, Adekunle A O, Mati J, Otubu J, Reidenberg M M, Segal S J
Maternidade Climério de Oliveira, Federal University of Bahia, Salvador, Bahia, Brazil.
Contraception. 2000 Jan;61(1):61-7. doi: 10.1016/s0010-7824(99)00117-1.
The safety and efficacy of gossypol continues to be controversial. The aim of this study was to evaluate gossypol as a contraceptive pill for men at doses lower than those previously prescribed and in men from various ethnic origin. A total of 151 men from Brazil, Nigeria, Kenya, and China were divided into two groups. Both groups received 15 mg gossypol/day for 12 or 16 weeks to reach spermatogenesis suppression. Subjects were then randomized to either 7.5 or 10 mg/day for 40 weeks. In addition, 51 men were enrolled as a control group. In all, 81 subjects attained spermatogenesis suppression. Only one man discontinued treatment because of tiredness. Potassium levels fluctuated within the normal range. FSH increased consistently. Testicular volume decreased, but after discontinuation, values returned to levels not statistically different from admission. Of 19 subjects on the 7.5 mg/day dose group, 12 recovered sperm counts >20 million/mL within 12 months of discontinuing gossypol. In the 10 mg/day group, sperm counts recovered in only 10 of 24 subjects. Eight of the 43 patients remained azoospermic 1 year after stopping gossypol. All men diagnosed with varicocele failed to reverse spermatogenesis suppression. Gossypol blood levels indicated that sperm suppression occurs independently of concentration, whereas spermatogenesis recovery appears to be concentration-dependent. Gossypol may become a medical alternative to surgical vasectomy when the delay in onset of infertility is acceptable. When taken for 1 year, gossypol causes no reduction in sexual desire or frequency of intercourse. The possibility of reversal, occurring in 51% of the men on this regimen within 1 year after stopping gossypol, is an advantage of this compound as compared with surgical sterilization in many parts of the world.
棉酚的安全性和有效性一直存在争议。本研究的目的是评估棉酚作为男性避孕药的效果，使用剂量低于先前规定剂量，并针对不同种族的男性进行研究。共有来自巴西、尼日利亚、肯尼亚和中国的151名男性被分为两组。两组均接受每日15毫克棉酚，持续12或16周，以达到抑制精子发生的效果。然后将受试者随机分为每日7.5毫克或10毫克组，持续40周。此外，51名男性作为对照组。总共有81名受试者达到了精子发生抑制。只有一名男性因疲劳而停止治疗。钾水平在正常范围内波动。促卵泡生成素持续升高。睾丸体积减小，但停药后，数值恢复到与入院时无统计学差异的水平。在每日7.5毫克剂量组的19名受试者中，12人在停用棉酚后的12个月内精子计数恢复至>2000万/毫升。在每日10毫克组中，24名受试者中只有10人精子计数恢复。43名患者中有8人在停用棉酚1年后仍无精子。所有被诊断为精索静脉曲张的男性均未能恢复精子发生抑制。棉酚血药浓度表明，精子抑制的发生与浓度无关，而精子发生的恢复似乎与浓度有关。当不育症发作的延迟可以接受时，棉酚可能成为手术输精管切除术的一种医学替代方法。服用1年后，棉酚不会导致性欲或性交频率降低。与世界许多地区的手术绝育相比，在停药后1年内，51%的男性出现恢复生育能力的可能性是这种化合物的一个优势。
