Akaike T, Noguchi Y, Ijiri S, Setoguchi K, Suga M, Zheng Y M, Dietzschold B, Maeda H
Department of Microbiology, Kumamoto University School of Medicine, Japan.
Proc Natl Acad Sci U S A. 1996 Mar 19;93(6):2448-53. doi: 10.1073/pnas.93.6.2448.
The role of nitric oxide (NO) in the pathogenesis of influenza virus-induced pneumonia in mice was investigated. Experimental influenza virus pneumonia was produced with influenza virus A/Kumamoto/Y5/67(H2N2). Both the enzyme activity of NO synthase (NOS) and mRNA expression of the inducible NOS were greatly increased in the mouse lungs; increases were mediated by interferon gamma. Excessive production of NO in the virus-infected lung was studied further by using electron spin resonance (ESR) spectroscopy. In vivo spin trapping with dithiocarbamate-iron complexes indicated that a significant amount of NO was generated in the virus-infected lung. Furthermore, an NO-hemoglobin ESR signal appeared in the virus-infected lung, and formation of NO-hemoglobin was significantly increased by treatment with superoxide dismutase and was inhibited by N(omega)-monomethyl-L-arginine (L-NMMA) administration. Immunohistochemistry with a specific anti-nitrotyrosine antibody showed intense staining of alveolar phagocytic cells such as macrophages and neutrophils and of intraalveolar exudate in the virus-infected lung. These results strongly suggest formation of peroxynitrite in the lung through the reaction of NO with O2-, which is generated by alveolar phagocytic cells and xanthine oxidase. In addition, administration of L-NMMA resulted in significant improvement in the survival rate of virus-infected mice without appreciable suppression of their antiviral defenses. On the basis of these data, we conclude that NO together with O2- which forms more reactive peroxynitrite may be the most important pathogenic factors in influenza virus-induced pneumonia in mice.
研究了一氧化氮（NO）在小鼠流感病毒诱导性肺炎发病机制中的作用。用甲型流感病毒A/熊本/Y5/67（H2N2）诱发实验性流感病毒肺炎。小鼠肺组织中一氧化氮合酶（NOS）的酶活性和诱导型NOS的mRNA表达均显著增加；这些增加是由γ干扰素介导的。通过电子自旋共振（ESR）光谱进一步研究了病毒感染肺组织中NO的过量产生。用二硫代氨基甲酸盐-铁络合物进行体内自旋捕获表明，病毒感染的肺组织中产生了大量NO。此外，病毒感染的肺组织中出现了NO-血红蛋白ESR信号，超氧化物歧化酶处理可显著增加NO-血红蛋白的形成，而N（ω）-单甲基-L-精氨酸（L-NMMA）给药可抑制其形成。用特异性抗硝基酪氨酸抗体进行免疫组织化学分析显示，病毒感染的肺组织中肺泡吞噬细胞如巨噬细胞和中性粒细胞以及肺泡内渗出物有强烈染色。这些结果有力地表明，肺组织中通过NO与O2-反应形成过氧亚硝酸盐，O2-由肺泡吞噬细胞和黄嘌呤氧化酶产生。此外，给予L-NMMA可显著提高病毒感染小鼠的存活率，而对其抗病毒防御无明显抑制作用。基于这些数据，我们得出结论，NO与形成更具反应性的过氧亚硝酸盐的O2-一起可能是小鼠流感病毒诱导性肺炎中最重要的致病因素。
