Division of Endocrinology, Central Drug Research Institute (CSIR), Lucknow 226 001, India.
Hum Reprod. 2010 May;25(5):1165-76. doi: 10.1093/humrep/deq036. Epub 2010 Feb 22.
We have attempted to identify structural, physiological and other targets on human sperm vulnerable to the spermicidal action of two novel series of non-detergent molecules, reported to irreversibly immobilize human sperm in <30 s, apparently without disrupting plasma membrane.
Three sperm samples were studied. Scanning and transmission electron microscopy were used to assess structural aberrations of sperm membrane; plasma membrane potential and intracellular pH measurements (fluorometric) were used to detect changes in sperm physiology; reactive oxygen species (ROS, fluorometric) and superoxide dismutase activity (colorimetric) were indicators of oxidative stress; and sperm dynein ATPase activity demonstrated alterations in motor energy potential, in response to spermicide treatment. Post-ejaculation tyrosine phosphorylation of human sperm proteins (immunoblotting) was a marker for functional integrity.
Disulfide esters of carbothioic acid (DSE compounds) caused complete sperm attenuation at > or =0.002% concentration with hyper-polarization of sperm membrane potential (P < 0.001), intracellular alkalinization (P < 0.01), ROS generation (P < 0.05) and no apparent effect on sperm (n = 150) membrane structure. Isoxazolecarbaldehyde compounds required > or =0.03% for spermicidal action and caused disrupted outer acrosomal membrane structure, depolarization of membrane potential (P < 0.001), intracellular acidification (P < 0.01) and ROS generation (P < 0.01). Detergent [nonoxynol-9 (N-9)] action was sustainable at > or =0.05% and involved complete breakdown of structural and physiological membrane integrity with ROS generation (P < 0.001). All spermicides caused functional attenuation of sperm without inhibiting motor energetics. Unlike N-9, DSE-37 (vaginal dose, 200 microg) completely inhibited pregnancy in rats and vaginal epithelium was unchanged (24 h,10 mg).
The study reveals a unique mechanism of action for DSE spermicides. DSE-37 holds promise as a safe vaginal contraceptive. CDRI Communication No. 7545.
我们试图确定人类精子的结构、生理和其他靶点，这些靶点容易受到两种新型非去污剂分子的杀精作用的影响，据报道，这两种分子能在<30 秒内不可逆地使人类精子失活，显然不会破坏质膜。
研究了三个精子样本。扫描和透射电子显微镜用于评估精子膜的结构异常；质膜电位和细胞内 pH 值测量（荧光法）用于检测精子生理变化；活性氧（ROS，荧光法）和超氧化物歧化酶活性（比色法）是氧化应激的指标；精子动力蛋白 ATP 酶活性显示，在杀精剂处理后，运动能量潜力发生变化。射精后人类精子蛋白的酪氨酸磷酸化（免疫印迹）是功能完整性的标志物。
碳二硫代羧酸的二硫酯（DSE 化合物）在>或=0.002%的浓度下引起完全的精子衰减，导致精子膜电位超极化（P<0.001）、细胞内碱化（P<0.01）、ROS 生成（P<0.05），对精子（n=150）膜结构无明显影响。异恶唑甲酰基化合物需要>或=0.03%才能产生杀精作用，并导致外顶体膜结构破坏、膜电位去极化（P<0.001）、细胞内酸化（P<0.01）和 ROS 生成（P<0.01）。去污剂[壬烷-9（N-9）]的作用可持续>或=0.05%，并导致结构和生理膜完整性的完全破坏，同时产生 ROS（P<0.001）。所有杀精剂都会导致精子功能衰减，而不会抑制运动能量。与 N-9 不同，DSE-37（阴道剂量 200μg）完全抑制了大鼠的妊娠，且阴道上皮无变化（24 小时，10mg）。
该研究揭示了 DSE 杀精剂的独特作用机制。DSE-37 有望成为一种安全的阴道避孕药。CDRI 通讯号 7545。
