研究男性不育的專家發(fā)現(xiàn)：糖酵解途徑的關鍵成分，甘油醛-3-磷酸脫氫酶(glyceraldehyde 3-phosphate dehydrogenase, GAPD)在精子細胞生成遷移至卵子所需能量過程中是必不可少的，

美國北卡羅萊納大學醫(yī)學院(Chapel Hill, NC, USA)的研究人員，通過基因工程培養(yǎng)了一個不表達GAPDS基因的小鼠品系，GAPDS是小鼠精子細胞中存在的酶。研究人員在2004年11月6日《美國國立科學院學報》在線版報道說：盡管這些動物能夠與正常的雌性小鼠進行交配，這些小鼠都不能生育。在顯微鏡下檢查了小鼠精子發(fā)現(xiàn)，精子只能進行側(cè)向移動，卻不能向前移動。

在生化水平發(fā)現(xiàn)盡管線粒體氧消耗沒有發(fā)生改變，但是來自這些小鼠精子的三磷酸腺苷(adenosine triphosphate, ATP)水平只有對照小鼠的10.4％。由此可見，精子活動所需的大部分能量是由糖酵解產(chǎn)生的，而不是氧化磷酸化。

美國北卡羅萊納大學醫(yī)學院細胞與發(fā)育生物學副教授、高級作者Deborah O'Brien博士說：“我們對這些發(fā)現(xiàn)十分驚奇，這證實了幾乎全部精子活力與ATP的產(chǎn)生都依賴于這個酶。“

因為人類精子中存在GAPD，作者提示該酶可以成為避孕藥物的一個良好的作用靶點，而環(huán)境中存在的能夠影響其活性的化學制劑可能與人類男性不育有關。
 
Glycolysis Produces the Power for Sperm Motility
 
Researchers studying male infertility have found that the enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPD), a key component of the glycolysis pathway, is required to produce the energy needed by sperm cells to migrate towards the awaiting eggs.

Investigators at the University of North Carolina Medical School (Chapel Hill, NC, USA) genetically engineered a line of mice lacking the gene for GAPDS, the form of the enzyme found in mouse sperm cells. They reported in the November 16, 2004, online edition of the Proceedings of the [U.S.] National Academy of Sciences that while these animals mated normally with receptive female mice, they were infertile. Examination of their sperm under the microscope revealed that the sperm showed only a slight side-to-side movement, but were incapable of moving forward.

At the biochemical level it was found that although mitochondrial oxygen consumption was unchanged, sperm from these mice had adenosine triphosphate (ATP) levels that were only 10.4% of those in sperm from control mice. Thus, most of the energy required for sperm motility was generated by glycolysis rather than oxidative phosphorylation.

“We were very surprised at this finding,” said senior author Dr. Deborah O’Brien, associate professor of cell and developmental biology at the University of North Carolina School of Medicine. “It turned out that almost all of the sperm’s motility and ATP production depended on this enzyme.”

Since a form of GAPD is present in human sperm, the authors suggested that it might be a good target for contraceptive agents, and that environmental agents that affect its activity may be related to male infertility in humans.