大鼠肺内NOS之分布及缺氧对其活性的影响

本文以组织化学方法对大鼠肺内一氧化氮合酶（ＮＯＳ）进行定位研究，并观察了不同时间（８小时～２８天）缺氧时肺内ＮＯＳ活性的变化。结果显示：①正常大鼠各级支气管、肺泡管和肺泡囊上皮细胞呈ＮＯＳ强阳性反应；肺血管内膜呈ＮＯＳ阳性反应。②缺氧８小时，肺血管内膜ＮＯＳ阳性反应开始降低，并缺氧时间越长，ＮＯＳ阳性反应越低、③缺氧１４天时，肺泡间质和肺血管周围炎性细胞呈ＮＯＳ阳性反应；缺氧２８天时，炎性细胞ＮＯＳ阳性反应增强。④缺氧对支气管、肺泡管和肺泡囊上皮细胞ＮＯＳ的活性无明显影响。从而提示一氧化氮不仅对肺具有一定的生理学作用，而且可能参与缺氧时肺的某些病理学过程。

HISTOCHEMICAL DISTRIBUTION OF NITRIC OXIDE SYNTHASE IN RAT LUNG AND EFFECT OF HYPOXIA ON ITS ACTIVITY

Nitric oxide(NO)may play a physiological and pathological role in lung.Although thedistribution of NO synthase(NOS)has been established in many organs,it remains uncertain in lung.In the present paper,NADPH-diahorase histochemical staining method wasused to investigate the distribution of NOS in normal and hypoxic lungs of rats. In normalrats, the NOS positive stain localized in epithelial cells of bronchi, alveolar duct and alveolarsac as well as in endothelium of pulmonary vessels. In those hypoxic rats,the activity ofNOS in pulmonary arterial endothelium was significantly lower than that in normal ones;andthe longer duration of hypoxia,the lower the activity of endothelial NOS.In those rats exposed to hypoxia after 14 and 28 days,the positive stain inflammatory cells were present inalveolar interstitium and surrounding pulmonary vessels. However,the NOS activities in epithelial cells of bronchi, alveolar duct and sac, in hypoxic rats were nit affected.This resultssuggests that NO may play an important role in physiology of liing and modulate some hypoxic pulmonary diseases.