Martin Feelisch is at the Dept of Nitric Oxide Research, Schwarz Pharma AG, Alfred Nobel Str. 10, D-40789 Monheim, Germany.
Trends Ecol Evol. 1995 Dec;10(12):496-9. doi: 10.1016/s0169-5347(00)89206-x.
Nitric oxide (NO), which today serves many different purposes in regulating complex cellular functions, must have played a crucial role in the early stages of the evolution of life. The formation of NO may have been a critical defence mechanism for primitive microorganisms at a time when life faced the problem of rising atmospheric levels of ozone (03) formed upon photolysis of oxygen (Oz), which occurred shortly after the development of respiration in cyanobacteria. The production of NO by organisms would have allowed neutralization of toxic 03 by chemical reaction outside the cell, thus acting as a protective mechanism against oxidative destruction, allowing evolutionary advantage. Later, NO production might have allowed the control of reactive OZ species within cells before the development of specific electron-accepting enzymes. The pathway of NO formation was then consequently developed further to serve other useful functions. Although mammalian cells produce NO from L-arginine, the origin of this ability might have arisen from the essential process of either nitrification or denitrification in prokaryotic cells.
一氧化氮（NO）在调节复杂细胞功能方面具有多种用途，它在生命进化的早期阶段肯定发挥了关键作用。在生命面临由于光合作用产生的氧气（O2）光解而形成的臭氧（O3）水平升高这一问题时，NO 的形成可能是原始微生物的关键防御机制。生物体产生的 NO 通过化学反应在细胞外中和有毒的 O3，从而起到抵抗氧化破坏的保护机制，使生物体具有进化优势。后来，在特定的电子受体酶出现之前，NO 的产生可能允许对细胞内的活性 OZ 物质进行控制。NO 形成的途径随后进一步发展，以发挥其他有用的功能。尽管哺乳动物细胞从 L-精氨酸中产生 NO，但这种能力的起源可能来自于原核细胞中硝化或反硝化的基本过程。
