Involvement of glutathione peroxidase and catalase in the disposal of exogenous hydrogen peroxide by cultured astroglial cells
Involvement of glutathione peroxidase and catalase in the disposal of exogenous hydrogen peroxide by cultured astroglial cells
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DOI：
10.1016/s0006-8993(97)00233-3
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发表时间：
1997-06-06
期刊：
影响因子：
2.9
通讯作者：
Hamprecht, B
中科院分区：
文献类型：
--
作者：
Dringen, R;Hamprecht, B
星形胶质细胞解毒外源性应用过氧化氢（H2 O2）的能力进行了测试，使用富含星形胶质细胞的原代培养物来自新生大鼠的大脑。星形胶质细胞与100 μ M H2 O2在葡萄糖的情况下孵育导致细胞谷胱甘肽在30秒内氧化66%。在这些条件下，细胞不能在孵育30分钟内重新建立原始的高GSH/GSSG比率。相反，如果存在葡萄糖，则在与H2 O2孵育时产生的GSSG的量较小（30 s后占总谷胱甘肽的45%），GSH/GSSG的原始比例在10 min内几乎完全恢复。如果使用100 μ M H2 O2，H2 O2从孵育缓冲液中消失，表观半衰期约为4 min。孵育15 min后，不再检测到H2 O2。孵育缓冲液中H2 O2的表观半衰期略有增加，但显着增加浓度的H2 O2或当细胞饥饿的葡萄糖。细胞解毒H2 O2的能力的一个小的减少后，也观察到的谷胱甘肽含量消耗到14%的控制水平，通过24小时的预孵育的细胞在培养基中含有丁硫氨酸亚砜亚胺，谷胱甘肽合成的抑制剂。星形胶质细胞与巯基琥珀酸酯或3-氨基三唑，谷胱甘肽过氧化物酶和过氧化氢酶的抑制剂，分别孵育，只有轻微减少的H2 O2从孵育缓冲液中消失的速度。与此相反，H2 O2清除率强烈降低的存在下，这两种抑制剂。这些结果表明谷胱甘肽过氧化物酶和过氧化氢酶参与了星形胶质细胞对H_2O_2的解毒作用，并且这两种酶在H_2O_2的解毒作用中能够相互替代。(C)1997年Elsevier Science B.V.
The ability of astroglial cells to detoxify exogenously applied hydrogen peroxide (H2O2) was tested using astroglia-rich primary cultures derived from the brains of newborn rats. Incubation of astroglial cells with 100 mu M H2O2 in the absence of glucose led to a 66% oxidation of the cellular glutathione within 30 s. Under these conditions, the cells were unable to re-establish the original high ratio of GSH/GSSG within 30 min of incubation. In contrast, if glucose was present the amount of GSSG produced on incubation with H2O2 was smaller (45% of total glutathione after 30 s) and the original ratio of GSH/GSSG was almost completely re-established within 10 min. If 100 mu M H2O2 was applied, H2O2 disappeared from the incubation buffer with an apparent half-life of approximate to 4 min. After 15 min of incubation, no H2O2 was detectable any more. The apparent half-life of H2O2 in the incubation buffer increased slightly but significantly with increasing concentration of H2O2 or when the cells were starved of glucose. A small reduction in the capacity of the cells to detoxify H2O2 was also observed after depletion of the glutathione content to 14% of control level by a 24 h pre-incubation of the cells in culture medium containing buthionine sulfoximine, an inhibitor of glutathione synthesis. Incubation of astroglial cells with mercaptosuccinate or 3-aminotriazole, inhibitors of glutathione peroxidase and catalase, respectively, only marginally reduced the rate of disappearance of H2O2 from the incubation buffer. In contrast, the rate of H2O2 clearance was strongly reduced in the presence of both inhibitors. These results demonstrate that glutathione peroxidase and catalase are involved inthe detoxification of H2O2 by astroglial cells and that both enzymes are able to substitute for each other in the detoxification of H2O2. (C) 1997 Elsevier Science B.V.