Daveu C, Servy C, Dendane M, Marin P, Ducrocq C
INSERM U 114, Collège de France, Paris.
Nitric Oxide. 1997 Jun;1(3):234-43. doi: 10.1006/niox.1997.0123.
The reactivity of catecholamines with nitrogen oxides formed from NO in aerated solutions, nitrite, and peroxynitrite was evaluated. Dopamine and norepinephrine in aerobic buffer (pH 7.4) were almost completely converted to their 6-nitro-derivatives by nitric oxide (NO) at room temperature, while epinephrine was nitrated and above all oxidized. The products obtained from each catecholamine treated with sodium nitrite at pH 4-7 were compared to those produced by NO at pH 7.4. Peroxynitrite, which can nitrate tyrosinyl residues, did not produce nitro-derivatives, only oxidized ones. The physiological relevance, particularly for the vascular and nervous system, is discussed. Catecholamine oxidation reactions could be relevant to physiological conditions and also explain neurotoxicity in Parkinson's disease and aging. Nitration reactions, requiring such high NO concentrations, do not seem possible to occur directly under normal physiological conditions, but could take place in acidic vesicules where nitrite, catecholamines, and their nitrated products could accumulate. Finally, the ability of dopamine to increase 2',5'-cyclic adenosine monophosphate (cAMP) formation in cultured striatal neurons was blocked by its nitration by NO or its nitrogen oxide derivatives.
评估了儿茶酚胺与在曝气溶液中由一氧化氮（NO）形成的氮氧化物、亚硝酸盐和过氧亚硝酸盐的反应活性。在室温下，有氧缓冲液（pH 7.4）中的多巴胺和去甲肾上腺素几乎完全被一氧化氮（NO）转化为其6-硝基衍生物，而肾上腺素则被硝化，尤其是被氧化。将在pH 4-7下用亚硝酸钠处理的每种儿茶酚胺所得到的产物与在pH 7.4下由NO产生的产物进行了比较。能够硝化酪氨酸残基的过氧亚硝酸盐没有产生硝基衍生物，只产生了氧化产物。讨论了其生理相关性，特别是对血管和神经系统的相关性。儿茶酚胺氧化反应可能与生理状况相关，也可以解释帕金森病和衰老中的神经毒性。硝化反应需要如此高的NO浓度，在正常生理条件下似乎不可能直接发生，但可能发生在酸性小泡中，亚硝酸盐、儿茶酚胺及其硝化产物可能在其中积累。最后，多巴胺在培养的纹状体神经元中增加2',5'-环磷酸腺苷（cAMP）形成的能力被其被NO或其氮氧化物衍生物硝化所阻断。
