内源性一氧化氮在感染性肺炎病理过程中的作用

Role of endogenous nitric oxide in pathogenesis of infectious pneumonia

目的：通过对感染性肺炎时一氧化氮（Ｎｉｔｒｉｃｏｘｉｄｅ，ＮＯ）的临床与实验研究，来探讨ＮＯ在感染性肺炎的病理过程中作用。方法：①急性肺炎患儿２６例，正常健康儿童３０例，测定血浆ＮＯ水平。②绿脓杆菌肺炎大白鼠模型１５只分别在２４、７２、１２０ｈ抽心血测定ＮＯ水平，对照组５只大白鼠。肺组织送光镜、电镜及细菌培养。结果：急性肺炎患儿血浆ＮＯ水平明显高于对照组（Ｐ＜０．０１）。绿脓杆菌肺炎大鼠模型ＮＯ水平２４ｈ升高，７２ｈ达高峰，１２０ｈ明显降低，各时相点ＮＯ水平与对照组差异显著（Ｐ＜０．０５），光镜、电镜示肺泡上皮细胞明显损伤，肺间质炎性细胞浸润，肺泡腔内充满红细胞。结论：在感染性肺炎时ＮＯ水平的改变。

Objective: To investigate the role of nitric oxide (NO) in pathogenesis of infectious pneumonia. Methods: ① The plasma level of NO was determined in 26 children with acute infectious pneumonia and 30 healthy children. ② The plasma level of NO was determined in 15 rats with infectious pneumonia caused by Pseudomonas aeruginosa and 5 controls at the 24th, 72nd and 120th h after bacterial challenge. Meanwhile, the samples of pulmonary tissue were examined with optical microscopy and electron microscopy and cultured. Results: The plasma level of NO was significantly higher in patients with acute infectious pneumonia than in the healthy individuals ( P <0.05). In the rats with infectious pneumonia, the plasma level of NO was significantly increased at the 24th h, peaked at 72nd h and markedly decreased at the 120th h after the bacterial challenge as compared with the controls (P <0.05). The optical and electron microscopy showed the injury of pulmonary alveolar epithelia, interstitial infiltration of inflammatory cells and accumulation of red blood cells in the alveolar cavity. Conclusion: The changes of NO level during infectious pneumonia might be one of the factors causing pulmonary injury.