美國(guó)一項(xiàng)最新研究揭示了引發(fā)精子游動(dòng)的奧秘,，這不僅有助于研發(fā)男性避孕藥，而且有助于使那些“行動(dòng)緩慢”的精子變得活躍起來(lái),。這一最新研究成果發(fā)表在《細(xì)胞》雜志上,。
人們通常認(rèn)為，精子好似一群活潑的小蝌蚪,，總是不停地蠕動(dòng)著,，但是事實(shí)上精子并非總是在四處游動(dòng)。研究人員發(fā)現(xiàn),，精子的游動(dòng)同其自身的酸堿度(pH值)變化有關(guān),。精液堿性越大，精子游動(dòng)更為有力,。不過(guò)截至目前,，精子是如何迅速釋放質(zhì)子，使自身的酸堿度從酸性變成堿性的機(jī)理尚不清楚,。
科研人員發(fā)現(xiàn),，精子長(zhǎng)有大量的小毛孔，能夠釋放質(zhì)子,，使自身的酸堿度變成堿性,，從而開(kāi)始游動(dòng)。美國(guó)加州大學(xué)的研究小組將這些毛孔稱(chēng)為“Hv1 質(zhì)子管道”,。研究人員發(fā)現(xiàn),，“Hv1 質(zhì)子管道”會(huì)在許多不同情況下開(kāi)啟，包括當(dāng)外界pH值堿性增大時(shí),，或者精子接觸到內(nèi)源性大麻素物質(zhì)時(shí),。內(nèi)源性大麻素物質(zhì)是一種男性和女性生殖系統(tǒng)中都存在的化學(xué)物質(zhì)，不過(guò)研究人員表示,，這一化學(xué)物質(zhì)更集中于女性卵細(xì)胞附近,。對(duì)精子游動(dòng)促發(fā)機(jī)制的更好理解有助于研制出更為有效的男性避孕藥，或者說(shuō)給予那些“行動(dòng)緩慢”的精子以激勵(lì),，促使其“奮勇向前”,。
除了有助于研制避孕藥以及促進(jìn)受孕之外,，這一研究還能揭示為什么大麻會(huì)損害男性的生育能力。內(nèi)源性大麻素物質(zhì)同大麻的主要成分非常接近,。研究人員推測(cè)說(shuō),，如果男子吸食大麻，大麻中的這一成分會(huì)誘騙精子開(kāi)始游動(dòng),，在真正需要精子“沖鋒陷陣”時(shí),，它們已經(jīng)筋疲力盡了。（生物谷Bioon.com）
相關(guān)研究：
Nature：同源精子會(huì)抱團(tuán)前進(jìn)
JCI：發(fā)現(xiàn)一種保護(hù)精子的抗氧化酶
Biological Reviews：男性超級(jí)精子游動(dòng)過(guò)快可能導(dǎo)致不孕
生物谷推薦原始出處：
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.
