Pan Li, Xu Wei, Fu Jian-Hua, Xue Xin-Dong
Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
Zhongguo Dang Dai Er Ke Za Zhi. 2009 Jul;11(7):581-4.
To study the effect of melatonin, a potent antioxidant both in vitro and in vivo, on hyperoxia-induced oxidant/antioxidant imbalance in the lung of neonatal rats with chronic lung disease (CLD).
Ninety neonatal rats were randomly divided into three groups (n=30 each): air-exposed, hyperoxia-exposed, melatonin-treated (4 mg/kg melatonin was administered 30 minutes before hyperoxia exposure and once daily after exposure). CLD was induced by hyperoxia exposure (FiO2=0.85). Lung specimens were obtained 3, 7, and 14 days after exposure (n=10 each) for histopathologic examination. The levels of total antioxydase capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), myeloperoxidase (MPO), catalase (CAT), nitrite/nitrate, and malondialdehyde (MDA) in the lung were assayed by the spectrophotometer.
The histopathologic examination showed that lung damage was obviously alleviated in the melatonin-treated group. The levels of T-AOC, GSH-Px, SOD and CAT in the lung were significantly higher in the melatonin-treated group than those in the other two groups at all time points (p<0.05). The levels of MPO, nitrite/nitrate and MDA in the lung increased significantly in the untreated hypoxia-exposed group compared with those in the air-exposed group at all time points (p<0.05 or 0.01), while the levels of MPO, nitrite/nitrate and MDA in the melatonin-treated group were significantly reduced as compared with the untreated hypoxia-exposed group (p<0.05).
Melatonin may reverse oxidant/antioxidant imbalance in hyperoxia-induced lung disease, thus providing a protective effect against CLD in neonatal rats.
研究褪黑素（一种在体内外均具有强大抗氧化作用的物质）对慢性肺疾病（CLD）新生大鼠肺脏中高氧诱导的氧化/抗氧化失衡的影响。
将90只新生大鼠随机分为三组（每组n = 30）：空气暴露组、高氧暴露组、褪黑素治疗组（在高氧暴露前30分钟给予4 mg/kg褪黑素，暴露后每天给药一次）。通过高氧暴露（FiO2 = 0.85）诱导CLD。在暴露后3、7和14天获取肺组织标本（每组n = 10）进行组织病理学检查。用分光光度计检测肺组织中总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、髓过氧化物酶（MPO）、过氧化氢酶（CAT）、亚硝酸盐/硝酸盐和丙二醛（MDA）的水平。
组织病理学检查显示，褪黑素治疗组的肺损伤明显减轻。在所有时间点，褪黑素治疗组肺组织中T-AOC、GSH-Px、SOD和CAT的水平均显著高于其他两组（p < 0.05）。在所有时间点，未处理的低氧暴露组肺组织中MPO、亚硝酸盐/硝酸盐和MDA的水平与空气暴露组相比显著升高（p < 0.05或0.01），而褪黑素治疗组肺组织中MPO、亚硝酸盐/硝酸盐和MDA的水平与未处理的低氧暴露组相比显著降低（p < 0.05）。
褪黑素可能逆转高氧诱导的肺部疾病中的氧化/抗氧化失衡，从而对新生大鼠的CLD起到保护作用。
