干扰素-γ在放射性肺损伤发生过程中的作用研究

目的：通过研究大鼠放射性肺损伤模型，探讨干扰素-γ（IFN-1）在放射性肺损伤的作用及机制，为临床预防和治疗放射性肺损伤提供新的思路。方法：建立Wistar大鼠半胸照射的放射性肺损伤实验动物模型．35只雄性Wistar大鼠随机分为正常对照组（N组），照射组（R1～R3组），照射＋药物组（D1～D3组）。其中D1～D3组大鼠在照射后第1天开始腹腔皮下注射IFN-γ 5万U／d，至照射后60d停止。每周记录1次Wistar大鼠的临床表现，分别在照射后2、4和12周取材，行常规病理检查，胶原纤维染色，观察IFN-γ对放射性肺损伤的作用。结果：照射后R组与D组体重差异有显著性（P=0．002），D组肺泡炎较R组轻微、发生时间推迟，且进展缓慢（P=0．002），放射性肺纤维程度较R组减弱，但差异无显著性（P=0．137）。D组的Ⅰ型和Ⅲ型胶原的表达显著低于R组（PⅠ型=0．035，PⅢ型=0．040）。结论：IFN-γ在放射性肺损伤的发生过程中抑制了Ⅰ型和Ⅲ型胶原的合成，有效减少了照射后的放疗反应．提高了实验动物在照射后的存活质量，延迟放射性肺泡炎的发生时间并降低其发生的程度。放射性肺纤维化有轻度减弱，可能与随访时间有关。著者文摘]

The role of IFN-γ in radiation-induced lung injury

Purpose: To present the effect of Interferon-γ （IFN-γ）in radiation-induced pulmonary pneumonitis，so that we can prevention and cure pulmonary pneumonitis in the future. Method: A single-dose of 30Gy irradiation of right hemithorax and sham right lung irradiation in Wistar rats was delivered meanwhile IFN-γ was admoved 5 WU per day for two months. And then the rats was sacrificed respectively at 14d，28d and 84d. The values was measured including clinical manifestation，pathological change (for instant hemotoxylin and eosin (H&;E) stain and collagen fibers specific stain). Result：We found the D and R groups lung tissue got weights significantly differently （P=0.002）and prevented the development of alveolitis（P=0.002）, but not fibrosis of lungs in radiation induced pulmonary injury rats（P=0.137）. The express of Collogen Ⅰand Collogen Ⅲ in R groups depressed significantly compared with D groups（PⅠ=0.035，PⅢ=0.040）. Conclusion：Early intervention with IFN-γ could inhibit the secretion of collogen Ⅲ and collogenⅠ,and prevent the development of alveolitis but not fibrosis of lungs in radiation induced pulmonary injury rats. The machanism was unknown as yet. Key words: IFN-γ；radiation-induced lung injury