Kanwar U, Kaur R, Chadha S, Sanyal S
Department of Zoology, Panjab University, Chandigarh, India.
Contraception. 1990 Nov;42(5):573-87. doi: 10.1016/0010-7824(90)90084-9.
Gossypol, a plant-derived polyphenolic compound known to exert contraceptive actions in men, inhibits 14C-glucose uptake in vitro in human ejaculated spermatozoa. Spermatozoal glucose uptake was found to increase monotonically up to 40 min, and then decreased by 60 min, possibly because of the saturation of the transport loci in the membrane. Gossypol at the concentrations of 5 and 10 microns caused a reduction of both the linear portion of the uptake and the fall afterwards. Gossypol similarly affects both the Na-dependent and -independent glucose uptake. The kinetic parameters of glucose uptake indicate that gossypol might be interfering with the transport/carrier protein as reduction in maximum uptake velocity (Vmax) was observed without any change in the affinity constant (Km). Similarly, gossypol also produced an increase in spermatozoal lipid peroxidation as evidenced by a steep rise in thiobarbituric acid reaction products in the human sperm cells. A significant decrease in total phospholipid level and the individual classes was noted after gossypol addition. Gossypol-induced inhibition of glucose uptake may be related to the generation of lipid peroxides and consequent membrane damage.
棉酚是一种源自植物的多酚类化合物，已知对男性有避孕作用，它在体外可抑制人类射出精子对14C-葡萄糖的摄取。发现精子对葡萄糖的摄取在40分钟内单调增加，然后在60分钟时下降，这可能是由于膜上转运位点饱和所致。5微米和10微米浓度的棉酚会导致摄取的线性部分及随后的下降均减少。棉酚对依赖钠和不依赖钠的葡萄糖摄取均有类似影响。葡萄糖摄取的动力学参数表明，棉酚可能干扰转运/载体蛋白，因为观察到最大摄取速度（Vmax）降低，而亲和常数（Km）没有任何变化。同样，棉酚还导致精子脂质过氧化增加，这在人类精子细胞中硫代巴比妥酸反应产物急剧上升中得到证明。添加棉酚后，总磷脂水平及各个类别均显著下降。棉酚诱导的葡萄糖摄取抑制可能与脂质过氧化物的产生及随之而来的膜损伤有关。
