研究:酗酒会导致肌肉无力

 　　WASHINGTON, April 21 (Xinhua) -- U.S. researchers said Monday that muscle weakness from long-term alcoholism may be due to an inability of mitochondria, the powerhouses of cells, to self- repair.

　　In research conducted with rats, the researchers found evidence that chronic¹ heavy alcohol use affects a protein involved in mitochondrial repair and muscle regeneration.

　　"The finding gives insight into why chronic heavy drinking often saps muscle strength and it could also lead to new targets for medication development," George Koob, director of the U.S. National Institute on Alcohol Abuse and Alcoholism that funded the study, said in a statement.

　　Researchers identify why alcoholism causes muscle weakness

　　Mitochondria are cellular³ structures that generate most of the energy needed by cells. When mitochondria become damaged, they can repair themselves through a process called mitochondrial fusion⁴ -- joining with other mitochondria and exchanging material such as DNA⁵.

　　While fusion is a well-known method for mitochondrial self- repair in many other tissues, most researchers assumed that the repair mechanism⁶ is unlikely to occur in skeletal muscle, which relies constantly on mitochondria for power. The reason is that mitochondria are squeezed so tightly in between the packed fibers⁷ of the skeletal muscle cells that they have little opportunity to interact.

　　To investigate whether mitochondria in the muscle could indeed fuse to regenerate⁸, researchers from the Thomas Jefferson University created a system to tag the mitochondria in skeletal muscle of rats with two different colors and then watch if they mingled⁹.

　　The study showed for the first time that the mitochondrial fusion does occur in the skeletal muscle cells, the researchers said.

　　They were also able to identify a key protein called mitofusin 1 (Mfn1) fusion proteins in the process and show that alcoholism interferes¹⁰ with the process.

　　In rats that were given an alcohol diet, Mfn1 levels decreased as much as 50 percent while other fusion proteins were unchanged. This decrease in Mfn1 was coupled with a dramatic decrease in mitochondrial fusion. When Mfn1 returned to normal, mitochondrial fusion did as well.

　　"That alcohol can have a specific effect on this one gene² involved in mitochondrial fusion suggests that other environmental factors may also alter specifically mitochondrial fusion and repair," said lead author Gyorgy Hajnoczky, professor of the Thomas Jefferson University.

　　He also suggested that knowing the proteins involved in mitochondrial fusion may aid in drug development for alcohol- related muscle weakness.

　　The findings were published in the U.S. Journal of Cell Biology.

1 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

2 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

3 cellular   

adj.移动的；细胞的，由细胞组成的

参考例句：

• She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
• Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。

4 fusion   

n.溶化；熔解；熔化状态，熔和；熔接

参考例句：

• Brass is formed by the fusion of copper and zinc. 黄铜是通过铜和锌的熔合而成的。
• This alloy is formed by the fusion of two types of metal.这种合金是用两种金属熔合而成的。

5 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

6 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

7 fibers   

光纤( fiber的名词复数 )； （织物的）质地； 纤维，纤维物质

参考例句：

• Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上，以硫酸钠为凝固剂，对胶原-PVA共混溶液进行湿法纺丝，制备了胶原-PVA复合纤维。
• Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。

8 regenerate   

vt.使恢复，使新生；vi.恢复，再生；adj.恢复的

参考例句：

• Their aim is to regenerate British industry.他们的目的是复兴英国的工业。
• Although it is not easy,you have the power to regenerate your life.尽管这不容易，但你有使生活重获新生的能力。

9 mingled   

混合，混入( mingle的过去式和过去分词 )； 混进，与…交往[联系]

参考例句：

• The sounds of laughter and singing mingled in the evening air. 笑声和歌声交织在夜空中。
• The man and the woman mingled as everyone started to relax. 当大家开始放松的时候，这一男一女就开始交往了。

10 interferes   

vi. 妨碍，冲突，干涉

参考例句：

• The noise interferes with my work. 这噪音妨碍我的工作。
• That interferes with my plan. 那干扰了我的计划。