美国一项最新研究揭示了引发精子游动的奥秘，这不仅有助于研发男性避孕药，而且有助于使那些“行动缓慢”的精子变得活跃起来。这一最新研究成果发表在《细胞》杂志上。
人们通常认为，精子好似一群活泼的小蝌蚪，总是不停地蠕动着，但是事实上精子并非总是在四处游动。研究人员发现，精子的游动同其自身的酸碱度(pH值)变化有关。精液碱性越大，精子游动更为有力。不过截至目前，精子是如何迅速释放质子，使自身的酸碱度从酸性变成碱性的机理尚不清楚。
科研人员发现，精子长有大量的小毛孔，能够释放质子，使自身的酸碱度变成碱性，从而开始游动。美国加州大学的研究小组将这些毛孔称为“Hv1 质子管道”。研究人员发现，“Hv1 质子管道”会在许多不同情况下开启，包括当外界pH值碱性增大时，或者精子接触到内源性大麻素物质时。内源性大麻素物质是一种男性和女性生殖系统中都存在的化学物质，不过研究人员表示，这一化学物质更集中于女性卵细胞附近。对精子游动促发机制的更好理解有助于研制出更为有效的男性避孕药，或者说给予那些“行动缓慢”的精子以激励，促使其“奋勇向前”。
除了有助于研制避孕药以及促进受孕之外，这一研究还能揭示为什么大麻会损害男性的生育能力。内源性大麻素物质同大麻的主要成分非常接近。研究人员推测说，如果男子吸食大麻，大麻中的这一成分会诱骗精子开始游动，在真正需要精子“冲锋陷阵”时，它们已经筋疲力尽了。
生物谷推荐原始出处：
Cell, Volume 140, Issue 3, 327-337, 5 February 2010 DOI:10.1016/j.cell.2009.12.053
Acid Extrusion from Human Spermatozoa Is Mediated by Flagellar Voltage-Gated Proton Channel
Polina V. Lishko, Inna L. Botchkina, Andriy Fedorenko, Yuriy Kirichok
Department of Physiology, University of California, San Francisco, UCSF Mail Code 2140, Genentech Hall, Room N272F, 600 16th Street, San Francisco, CA 94158, USA
Human spermatozoa are quiescent in the male reproductive system and must undergo activation once introduced into the female reproductive tract. This process is known to require alkalinization of sperm cytoplasm, but the mechanism responsible for transmembrane proton extrusion has remained unknown because of the inability to measure membrane conductance in human sperm. Here, by successfully patch clamping human spermatozoa, we show that proton channel Hv1 is their dominant proton conductance. Hv1 is confined to the principal piece of the sperm flagellum, where it is expressed at unusually high density. Robust flagellar Hv1-dependent proton conductance is activated by membrane depolarization, an alkaline extracellular environment, endocannabinoid anandamide, and removal of extracellular zinc, a potent Hv1 blocker. Hv1 allows only outward transport of protons and is therefore dedicated to inducing intracellular alkalinization and activating spermatozoa. The importance of Hv1 for sperm activation makes it an attractive target for controlling male fertility.
