Inhibition of Alloxan Action in Isolated Pancreatic Islets by Superoxide Dismutase, Catalase, and a Metal Chelator
Inhibition of Alloxan Action in Isolated Pancreatic Islets by Superoxide Dismutase, Catalase, and a Metal Chelator
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超氧化物歧化酶、过氧化氢酶和金属螯合剂对离体胰岛中四氧嘧啶作用的抑制
DOI：
10.2337/diab.29.3.213
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发表时间：
1980
期刊：
影响因子：
7.7
通讯作者：
S. Hamburger
中科院分区：
文献类型：
--
作者：
L. J. Fischer;S. Hamburger
超氧阴离子，过氧化氢和羟基自由基的可能参与四氧嘧啶的行动进行了研究，使用离体大鼠胰岛。胰岛暴露于四氧嘧啶（0.15或0.2毫克/毫升）5分钟抑制随后的葡萄糖刺激的胰岛素释放。超氧化物歧化酶（1000 U/ml）、过氧化氢酶（50 μg/ml）或金属螯合剂二亚乙基三胺五乙酸（1 mM）的存在显著减弱了四氧嘧啶的这种作用。使用这些试剂提供了对较低浓度的四氧嘧啶的完全保护和对较高浓度的毒性化合物的部分保护。在螯合剂与四氧嘧啶一起使用之前，使酶失活或向螯合剂中加入过量的铁可消除这些试剂的保护作用。结果是一致的建议，羟基自由基，通过涉及超氧阴离子，过氧化氢和铁的反应，介导的四氧嘧啶在胰岛的有害影响。
The possible participation of superoxide anions, hydrogen peroxide, and hydroxyl radicals in the action of alloxan was investigated using isolated rat pancreatic islets. Exposure of islets for 5 min to alloxan (0.15 or 0.2 mg/ml) inhibited subsequent glucose-stimulated insulin release. The presence of superoxide dismutase (1000 U/ml), catalase (50 μg/ml), or a metal chelator diethylenetriaminepentacetic acid (1 mM) markedly attenuated this effect of alloxan. Use of these agents afforded complete protection from the lower concentration of alloxan and partial protection from the higher concentration of the toxic compound. Inactivation of the enzymes or addition of excess iron to the chelating agent before its use with alloxan eliminated the protective action of these agents. The results are consistent with the proposal that hydroxyl radicals, generated via reactions that involve superoxide anions, hydrogen peroxide, and iron, mediate the deleterious effect of alloxan in pancreaticislets.