高氧吸入后新生鼠肺组织一氧化氮及氧自由基的动态变化

Dynamic changes of nitric oxide and oxygen free radical in lung of neonatal rats after inhaling high concentration of oxygen

目的探讨持续吸入高氧后新生大鼠肺组织病理和一氧化氮(NO)及氧自由基的动态变化规律。方法足月新生鼠生后12h内分别持续吸入(90±5)%的高氧和空气,于1、3、7、14、21d,动态观察其肺组织病理学改变以及NO、MDA含量和SOD活性。结果肺形态学:吸高氧3d时炎性细胞渗出,7d时肺间隔增宽,终末气腔明显扩张,小肺泡数量减少,14和21d间质增生、肺泡化降低越来越明显;NO水平:在7、14和21d,高氧组水平高于空气组,数值分别为(99.38±7.80)vs(88.78±8.00),P<0.05;(128.18±33.78)vs(93.30±16.73),P<0.05;(170.66±34.00)vs(106.37±25.11),P<0.01;MDA含量:高氧组在3、7和14d高于空气组,数值分别为(28.10±2.03)vs(22.11±1.25),P<0.05;(30.82±4.17)vs(19.91±2.17),P<0.01;(26.27±3.78)vs(22.56±2.35),P<0.05;SOD的活性,在吸高氧7、14和21d时高于空气组(213.87±18.58)vs(185.55±18.79),P<0.05;(219.81±4.17)vs(19.91±2.71),P<0.01;(251.09±15.10)vs(194.56±8.12),P<0.01。结论持续吸入高氧可致新生大鼠发生与人类BPD类似的病理改变;肺组织的自由基损伤,可能在疾病发生、发展过程中起重要作用。

To determine dynamic changes of lung histological change and nitric oxide and oxygen free radical in lung of neonatal rats after inhaling high concentration of oxygen. Full-term newborn rats were continuously exposed to oxygen (90±5)% or room air (21% O2) after birth within 12 hours. Dynamic changes of lung histological changes and nitric oxide (NO), content of malondialdehyde (MDA), superoxide dismutase (SOD) activity in the lung were monitered by spectrophotometer on days 1, 3, 7, 14 and 21 in hyperoxia groups and controls. Lung morphometrical chage: In hyperoxia group, inflammatory cell inifiltration was seen on 3 d of inhaling high concentration of oxygen, on 7 d alveolar septa were widen with enlarged terminal airways and decreased number of alveoli, on 14 and 21 d interstitial hyperplasia and decreased alveolarization were more and more evident; Level of NO: on 7, 14, 21d was higher than control, data were: (99.38±7.80) vs (88.78±8.00), P <0.05; (128.18±33.78) vs (93.30±16.73), P <0.05; (170.66±34.00) vs (106.37±25.11), P <0.01; MDA concentration in the lung: on 3, 7, 14 d was higher than control, data were: (28.10±2.03) vs (22.11±1.25), P <0.05; (30.82±4.17) vs (19.91±2.17), P <0.01; (26.27±3.78) vs (22.56±2.35), P <0.05; SOD activity in lung: compared with air group, was increased on 7, 14, 21 d, data were: (213.87±18.58) vs (185.55±18.79), P <0.05; (219.81±4.17) vs (19.91±2.71), P <0.01; (251.09±15.10) vs (194.56±8.12), P <0.01. [Conclusion] After prolonged inhaling high concentration of oxygen, neonatal rats show a lesion that is very similar to human BPD and lead to free radical injury, which maybe important.