Kooy N W, Royall J A, Ye Y Z, Kelly D R, Beckman J S
Department of Pediatrics, University of Alabama at Birmingham.
Am J Respir Crit Care Med. 1995 Apr;151(4):1250-4. doi: 10.1164/ajrccm/151.4.1250.
Oxidant-mediated toxicity resulting from acute pulmonary inflammation has been demonstrated in acute lung injury. A potent biological oxidant, peroxynitrite, is formed by the near diffusion-limited reaction of nitric oxide with superoxide. In addition to having hydroxyl radical-like oxidative reactivity, peroxynitrite is capable of nitrating phenolic rings, including protein-associated tyrosine residues. Nitric oxide does not directly nitrate tyrosine residues, therefore, demonstration of tissue nitrotyrosine residues infers the action of peroxynitrite or related nitrogen-centered oxidants. Lung tissue was obtained from formalin-fixed, paraffin-embedded autopsy specimens, and specific polyclonal and monoclonal antibodies to nitrotyrosine were visualized by diaminobenzidene-peroxidase staining. Acute lung injury resulted in intense staining throughout the lung, including lung interstitium, alveolar epithelium, proteinaceous alveolar exudate, and inflammatory cells. In addition, staining of the vascular endothelium and subendothelial tissues was present in those patients with sepsis-induced acute lung injury. Antibody binding was blocked by coincubation with nitrotyrosine or nitrated bovine serum albumin but not by aminotyrosine, phosphotyrosine, or bovine serum albumin. Reduction of tissue nitrotyrosine to aminotyrosine by sodium hydrosulfite also blocked antibody binding. In control specimens with no overt pulmonary disease, there was only slight staining of the alveolar septum. These results demonstrate that nitrogen-derived oxidants are formed in human acute lung injury and suggest that peroxynitrite may be an important oxidant in inflammatory lung disease.
急性肺损伤中已证实急性肺部炎症会导致氧化介导的毒性。一种强效生物氧化剂——过氧亚硝酸盐，由一氧化氮与超氧化物近乎扩散受限的反应形成。除了具有类似羟基自由基的氧化反应活性外，过氧亚硝酸盐还能够硝化酚环，包括与蛋白质相关的酪氨酸残基。一氧化氮不会直接硝化酪氨酸残基，因此，组织中硝基酪氨酸残基的存在推断出过氧亚硝酸盐或相关含氮中心氧化剂的作用。肺组织取自福尔马林固定、石蜡包埋的尸检标本，通过二氨基联苯胺 - 过氧化物酶染色观察硝基酪氨酸的特异性多克隆和单克隆抗体。急性肺损伤导致整个肺部出现强烈染色，包括肺间质、肺泡上皮、蛋白质性肺泡渗出物和炎性细胞。此外，脓毒症诱导的急性肺损伤患者的血管内皮和内皮下组织也有染色。抗体结合可通过与硝基酪氨酸或硝化牛血清白蛋白共同孵育而被阻断，但不能被氨基酪氨酸、磷酸酪氨酸或牛血清白蛋白阻断。亚硫酸氢钠将组织中的硝基酪氨酸还原为氨基酪氨酸也可阻断抗体结合。在无明显肺部疾病的对照标本中，仅肺泡隔有轻微染色。这些结果表明，在人类急性肺损伤中会形成氮衍生的氧化剂，并提示过氧亚硝酸盐可能是炎症性肺病中的一种重要氧化剂。
