摘要
跨膜离子流动在启动配子间的相互作用，如顶体反应过程中有重要作用。但由于精子太小，无用论细胞内记录或膜片箝技术都难以对哺乳动物精子膜的离子通道进行研究。本工作将通道蛋白重组于脂双层，在电压箝位下记录了人精子膜的Ca2+通道电流。由12个健康人的精子分离的膜蛋白通过融合重组于脂双层后，在CaCl2溶液中（cis50／／trans10mmol/L）记录到两类单通道活动，它们的平衡电位都接近Ca2+的Nemst电位理论值；都对nifedipine和verapamil敏感；单位电导分别为40和25pS，但前者的平均开放时间无电压依赖性，后者（25pS）在维持电压从-20mV增至100mV时，通道平均开放时间增大。在两例不育者精子样本中亦发现可通透Ca2+的阳离子通道，但通道活动显示某些动力学异常。
Ionic flux is thougb to be Anportan in the inihating pe of pe interachon such asacrosome reaction. Howewr, modem electrophyological metods , intracellular recording and Patoh-clamping,are ffeult to approach the ion channch in mammal sperm membrane of an intact sperm due to its small size.In this work, by reconstituting the channel win into lipul bilayer, Ca2+ channels in human speozoawere inVedgatal with voltag clamp technique. Membrane protains isolatal bo human sperm of 12 healthdonors were incoporated into lipid bilayer via fusion. In a cis 50//trans 10 mmol/L CaCl2 solution system,two pe of chaxmel eVents with similar reversal potential near the value of a peho Ca+ eleced, andSendtive to nifedipine and verapamil, were for. ber wht conductance was 40 and 25 pS mendvely.Pementag of channel pe the was at dependent to holding potential for tha foarer. Howevr, for thecbo of 25 gh, the pemp increased when the hokhag potential was changed from - 20 to 100 mV.Ca2+ -permeable channels were the detectal bo the spermatco Saznpe of two infertile dsnors. Abnormal open the of these cbo edcates tha bo are some defects in tha conformaon of the channe protein of infertile spenn membran.
出处
《生理学报》
CAS
CSCD
北大核心
1999年第5期571-579,共9页
Acta Physiologica Sinica
基金
国家自然科学基金
关键词
钙离子通道
人
精子质膜
脂双层
重组
膜片箝
Ca^(2+)-channel
human spermatozoon
lipid bilayer
reconstitution
