Abstract: Hydrogen have diverse biological functions. However, the mechanism of  hydrogen function has always been debated. It is widely accepted that hydrogen selectively reduces cytotoxic oxygen radicals. However, the evidence of direct reaction between hydrogen and free radicals under physiological conditions is not sufficient, most of which are indirect evidences. It is impossible to distinguish whether hydrogen reacts directly with free radicals or affects the production of free radicals. Hydrogen has antioxidant effect, but our research showed that it was not to eliminate the free radicals after they were generated, but to reduce the generation of free radicals. It was similar to turn off the "switch" at the beginning of the generation of free radicals. Hydrogen could improve the activity of biological enzymes including mitochondrial complex Ⅰ, acetylcholinesterase and HRP, and affected mitochondrial membrane potential and regulate the membrane potential of nerve cells. Some of the oxidoreductases and ion channels of cell membrane are regulated by hydrogen. Taken together, hydrogen has multi-targets with bio-enzyme basis and higher organisms have hydrogenase ativity to metabolize hydrogen. This paper mainly discussed the relationship between hydrogen and free radicals, and the enzyme basis of hydrogen is important for its biological function, which was expected to provide reference for research on the mechanism of how hydrogen function.

Key words: hydrogen, hydrogenase, free radical, mitochondrial complexⅠ, energy metabolism

摘要： 氢气具有广泛的生物学功能，近年来逐渐引起广泛关注。但是氢气发挥生物学作用的机理一直都有争论，制约了氢生物学的进一步发展。现在被广泛接受的是氢气选择性与毒性自由基反应的理论，但是生理条件下氢气与自由基直接反应的证据并不充分，多数属于间接证据，无法区分氢气是与自由基直接反应还是影响了自由基的产生。氢气具有抗氧化作用，本团队研究表明，氢气不是在自由基产生之后去清除，而是减少自由基的产生，类似于在自由基产生之初就关上“开关”；氢气可以提高包括线粒体复合物Ⅰ、乙酰胆碱酯酶、HRP在内的生物酶的活性，可以影响线粒体膜电位和调节神经细胞膜电位，细胞膜的氧化还原酶类及离子通道等都受到氢气的调节，这表明氢气的作用可能是多靶点的主要基于酶学反应的过程，高等生物具有产生和利用氢气的氢化酶活性。主要探讨了氢气和自由基的关系以及氢气作用的生物酶学基础，以期为揭示氢气发挥生物学作用的机理提供参考。

关键词: 氢气, 氢化酶, 自由基, 线粒体复合物Ⅰ, 能量代谢