Exhaled nitric oxide and radiation pneumonitis

(1)临床研究：检测肺癌患者呼出一氧化氮水平，肺癌患者呼出一氧化氮水平高于对照组。在40gy辐照时和放疗后，呼出一氧化氮水平下降。8例患者呼出一氧化氮升高是放疗前的三倍或更多。其中3名患者表现出放射性肺炎的症状。另一方面，其他患者均无放射性肺炎征象（p=0.002）。放射治疗可以降低NO的升高水平，呼出的NO水平可能对放射性肺炎的早期预测有用。(2)病例报告：73例男性特发性间质性肺炎伴鳞状细胞肺癌（T2N1M0）行胸部放疗不化疗。他显示呼出的NO水平在30 Gy/50 Gy时升高，在10-20 Gy时下降。50 Gy时CT检查亦见异常影。虽然呼出一氧化氮在出现严重临床症状前可能有预测放射性肺炎的价值，但他在放疗后3个月因放射性肺炎恶化而死亡。(3)基础研究：检测辐照对大鼠巨噬细胞和平滑肌细胞NO水平的影响。辐射不影响iNOS mRNA的表达和培养基中NO的浓度，但增强了LPS、ifn - γ和il - 1- β诱导的mRNA的表达。因此，辐射刺激通过间接作用于巨噬细胞和平滑肌细胞诱导NO的产生，

(1) Clinical study : We examined the exhaled NO level in patients with lung cancer that was higher in the patients with lung cancer than in control. Exhaled NO level decreased at the time 40 Gy irradiated and post radiotherapy. The elevation in exhaled NO of eight patients was triple or more than that seen in before radiotherapy. Three of these patiens showed signs of radiation pneumonitis. On the other hand, none of the other patients showed signs of radiation pneumonitis (p=0.002). Radiation therapy can lower exalted levels of NO, and the levels of exhaled NO level may be a useful for the early prediction of radiation pneumonitis.(2) Case Report : A 73 male with idiopathic interstitial pneumonitis underwent thoracic radiotherapy without chemotherapy for squamous cell lung cancer (T2N1M0). He showed elevation of exhaled NO level at 30 Gy/50 Gy after decreasing at 10-20 Gy. He also showed abnormal shadow in CT examination at 50 Gy. Although exhaled NO may have a merit to predict radiation pneumonitis before severe clinical symptom appeared, he died three months after radiotherapy for worsening of radiation pneumonitis.(3) Basic study : We examined alteration of NO level by irradiation in rat macrophage and smooth muscle cells. Radiation did not generate the expression of mRNA of iNOS and concentration of NO in medium, but enhance the expression of mRNA that was induced by LPS, IFN-gamma and IL1-beta. Therefore, radiation stimulation induced NO production through indirect action on the macrophage and smooth muscle cells,