Glutathione modulates toxic oxygen metabolite injury of canine chief cell monolayers in primary culture.
Glutathione modulates toxic oxygen metabolite injury of canine chief cell monolayers in primary culture.
复制标题
谷胱甘肽调节原代培养中犬主细胞单层的有毒氧代谢损伤。
DOI：
10.1152/ajpgi.1988.254.1.g49
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Olson,CE
中科院分区：
文献类型：
--
作者：
Olson,CE
暴露于有毒氧代谢物生成系统（黄嘌呤加黄嘌呤氧化酶）的培养犬胃主细胞显示出最小的细胞溶解，表明这些细胞具有重要的内源性抗氧化机制。我们已经量化了谷胱甘肽对有毒氧代谢物的保护作用，通过测量在细胞谷胱甘肽含量的可变耗尽和补充后乳酸脱氢酶释放的细胞裂解。在没有外源氧化应激的情况下，主要细胞的谷胱甘肽含量在5小时内可以消耗到低于0.2 nmol总谷胱甘肽/微克DNA或对照组的22%，而不进行细胞裂解。然而，当受到氧代谢物生成系统的挑战时，谷胱甘肽的消耗大大增强了细胞裂解。谷胱甘肽耗竭后氧代谢物介导的细胞溶解被外源性过氧化氢酶、硫脲和去铁酰亚胺抑制，但不受超氧化物歧化酶或甘露醇的抑制。这些数据表明过氧化氢和羟基自由基介导的细胞溶解在谷胱甘肽耗尽的主要细胞。如果在缺氧的细胞中加入谷胱甘肽合成的底物n -乙酰- l-半胱氨酸1小时后再加入氧自由基生成系统，细胞裂解明显减少。然而，如果在饱食期被丁硫氨酸亚砜阻断谷胱甘肽的合成，则保护作用不会恢复。这些数据支持谷胱甘肽作为内源性抗氧化剂调节培养主细胞对毒性氧代谢物损伤的敏感性的重要作用。
Cultured canine gastric chief cells exposed to a toxic oxygen metabolite-generating system (xanthine plus xanthine oxidase) demonstrated minimal cytolysis, suggesting that these cells have important endogenous antioxidant mechanisms. We have quantified the role of glutathione for protection against toxic oxygen metabolites by measuring cell lysis by lactate dehydrogenase release after variable depletion and repletion of cellular glutathione content. In the absence of exogenous oxidant stress, the glutathione content of chief cells can be depleted to less than 0.2 nmol total glutathione/micrograms DNA or 22% of control without cell lysis over 5 h. However, when challenged with the oxygen metabolite-generating system, cytolysis was greatly enhanced by glutathione depletion. Oxygen metabolite-mediated cytolysis after glutathione depletion was inhibited by exogenous catalase, thiourea, and deferoximine, but not superoxide dismutase or mannitol. These data suggested that hydrogen peroxide and hydroxyl radical mediated cytolysis in glutathione-depleted chief cells. If a substrate for glutathione synthesis, N-acetyl-L-cysteine, was provided to the depleted cells for 1 h before challenge with the oxygen radical-generating system, cell lysis was markedly decreased. However, if glutathione synthesis was blocked during the repletion period by buthionine sulfoximine, protection was not restored. The data supported an important role for glutathione as an endogenous antioxidant, which modulated the sensitivity of cultured chief cells to toxic oxygen metabolite injury.