Protection from O2 toxicity by preexposure to hypoxia: lung antioxidant enzyme role.
Protection from O2 toxicity by preexposure to hypoxia: lung antioxidant enzyme role.
复制标题
通过预暴露于缺氧来防止氧气中毒：肺抗氧化酶的作用。
DOI：
10.1152/jappl.1982.53.2.475
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Frank,L
中科院分区：
文献类型：
--
作者：
Frank,L
预先暴露于 10% O2 3 天的成年大鼠对高氧引起的肺损伤和致死具有明显的耐受性。在高氧暴露 72 小时时，预暴露大鼠与未预暴露大鼠的存活率分别为 62/62 与 7/47 (15%)，P 小于 0.0001；在 9613;98% O2 中 7 天后，相对存活率为 31/33 (94%) 与 1/20 (5%)，P 小于 0.0005。缺氧暴露导致大鼠肺超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶和葡萄糖-6-磷酸脱氢酶活性显着升高。相比之下，在成年小鼠和仓鼠中，预先暴露于缺氧并没有增加肺部抗氧化酶水平，并且没有实现对高氧气的显着耐受性。 （缺氧预暴露和非预暴露小鼠的致死时间 50 值分别为 5.2 和 4.4 天；仓鼠分别为 6.4 和 6.1 天。）因此，缺氧预暴露的保护作用与肺抗氧化酶活性的适应性变化相关。文献证据表明，在缺氧条件下，超氧阴离子 (O-2) 和 H2O2 的产生可能会增加。在缺氧预暴露期间，其正常底物的细胞浓度增加可以刺激抗氧化酶的升高。
Adult rats preexposed to 10% O2 for 3 days had marked tolerance to hyperoxia-induced lung damage and lethality. The survival of preexposed vs. nonpreexposed rats at 72 h of hyperoxic exposure was 62/62 vs. 7/47 (15%), P less than 0.0001; and after 7 days in 9613;98% O2, the comparative survival was 31/33 (94%) vs. 1/20 (5%), P less than 0.0005. Hypoxic exposure produced significant elevations in rat lung superoxide dismutase, catalase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase activities. In contrast, in adult mice and hamsters, no increased lung antioxidant enzyme levels were produced by preexposure to hypoxia and no significant tolerance to high O2 was realized. (Lethal time50 values for hypoxia-preexposed and nonpreexposed mice, 5.2 and 4.4 days, respectively; and for hamsters, 6.4 and 6.1 days, respectively.) Thus the protective effect of hypoxic preexposure is correlated with adaptive changes in lung antioxidant enzyme activity. Evidence in the literature suggests that superoxide anion (O-2) and H2O2 production may increase under hypoxic conditions. Increased cellular concentrations of their normal substrates could stimulate antioxidant enzyme rises during the preexposure period in hypoxia.