GLUTATHIONE CYCLE ACTIVITY AND PYRIDINE-NUCLEOTIDE LEVELS IN OXIDANT-INDUCED INJURY OF CELLS
GLUTATHIONE CYCLE ACTIVITY AND PYRIDINE-NUCLEOTIDE LEVELS IN OXIDANT-INDUCED INJURY OF CELLS
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DOI：
10.1172/jci112068
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发表时间：
1985-01-01
影响因子：
15.9
通讯作者：
COCHRANE, CG
中科院分区：
文献类型：
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作者：
SCHRAUFSTATTER, IU;HINSHAW, DB;COCHRANE, CG
将靶细胞暴露在H2O2中，经过几个小时的潜伏期后，可诱导细胞裂解，只有在损伤后30分钟内通过添加过氧化氢酶去除H2O2才能防止细胞裂解。这表明，早期代谢事件的发生对暴露于氧化剂的细胞的命运很重要。在这项研究中，我们描述了h2o2诱导的P388D1巨噬细胞样肿瘤细胞损伤的两个早期独立事件：谷胱甘肽循环的激活和细胞NAD的消耗。加入H2O2后，谷胱甘肽循环和单磷酸己糖分流（HMPS）在数秒内被激活。高HMPS活性维持了大量减少的谷胱甘肽。然而，当HMPS活性被葡萄糖消耗或4度孵育抑制时。c -谷胱甘肽仍处于氧化状态。当细胞暴露于H2O2时，总吡啶核苷酸水平降低，分解产物烟酰胺在细胞外培养基中被回收。细胞内NAD水平在H2O2暴露20分钟内下降80%。用丁硫氨酸亚砜（BSO）阻断谷胱甘肽合成或用（1,3-二）2氯甲基-1-亚硝基脲抑制谷胱甘肽还原酶抑制谷胱甘肽循环，可防止NADP(H)的丢失和HMPS的刺激。NAD的丧失与谷胱甘肽循环和HMPS活性无关，因为它也发生在bso处理的细胞中。
Exposure of target cells to a bolus of H2O2 induced cell lysis after a latent period of several hours, which was prevented only when the H2O2 was removed within the first 30 min of injury by addition of catalase. This indicated that early metabolic events take place that are important in the fate of the cell exposed to oxidants. In this study, we described two early and independent events of H2O2-induced injury in P388D1 macrophagelike tumor cells: activation of the glutathione cycle and depletion of cellular NAD. Glutathione cycle and hexose monophosphate shunt (HMPS) were activated within seconds after the addition of H2O2. High HMPS activity maintained glutathione that was largely reduced. However, when HMPS activity was inhibited-by glucose depletion or by incubation at 4.degree. C-glutathione remained in the oxidized state. Total pyridine nucleotide levels were diminished when cells were exposed to H2O2, and the breakdown product, nicotinamide, was recovered in the extracellular medium. Intracellular NAD levels fell by 80% within 20 min of exposure of cells of H2O2. The loss of NADP(H) and stimulation of the HMPS could be prevented when the glutathione cycle was inhibited by either blocking glutathione synthesis with buthionine sulfoximine (BSO) or by inhibiting glutathione reductase with (1,3-bis) 2 chlorethyl-1-nitrosourea. The loss of NAD developed independently of glutathione cycle and HMPS activity, as it also occurred in BSO-treated cells.