Oxygen radicals mediate cell inactivation by acridine dyes, fluorescein, and lucifer yellow CH.
Oxygen radicals mediate cell inactivation by acridine dyes, fluorescein, and lucifer yellow CH.
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氧自由基通过吖啶染料、荧光素和荧光黄 CH 介导细胞失活。
DOI：
10.1111/j.1751-1097.1987.tb04734.x
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发表时间：
1987
影响因子：
3.3
通讯作者：
Logsdon,N
中科院分区：
文献类型：
--
作者：
Martin,JP;Logsdon,N
吖啶类染料、荧光素和荧光黄CH是实验上用来选择性染色和光动力学破坏真核细胞和亚细胞结构的荧光光敏剂。我们已经确定了E的光和氧依赖失活的机制。这些染料都含有氧自由基和过氧化氢，在光照下都能氧化NAD(P)H†。超氧化物歧化酶(O2-−)是染料敏化光氧化的主要产物，是铁细胞色素c的超氧化物歧化酶抑制还原反应。结肠细胞内光还原。还原染料扩散回细胞内，介导细胞外细胞色素c的还原。阴离子染料荧光素和荧光黄CH不能介导细胞外细胞色素c的还原，表明这些染料对细胞外的细胞色素c不具有通透性。胶膜。在光照下，吖啶类染料能抑制E。Coliin富含培养基，并诱导合成超氧化物歧化酶。荧光素和荧光黄CH由于不能进入细胞而不能抑制生长或诱导超氧化物歧化酶的合成。黄嘌呤氧化酶产生的超氧化物歧化酶(O2−)和过氧化氢(H2O2)是有毒的脚趾。大肠埃希菌。黄嘌呤氧化酶的失活可被外源超氧化物歧化酶部分抑制，被外源过氧化氢酶或超氧化物歧化酶加过氧化氢酶完全抑制。类似地，外源超氧化物歧化酶加过氧化氢酶可防止吖啶类药物和荧光素-NADH或荧光黄CH-NADH混合物的失活。预先诱导超氧化物歧化酶和过氧化氢酶。ColiB显著地保护细胞免受随后由照明的吖啶染料的挑战。超氧化物歧化酶和过氧化氢酶的预诱导结合外源超氧化物歧化酶和过氧化氢酶的添加，完全保护了E。吖啶黄对光动力失活的抑制作用。羟基自由基清除剂二甲基亚砜、苯甲酸钠和硫脲受到保护。结果表明，O2-−、H_2O_2和羟基自由基(OH-)是吖啶橙、吖啶黄、荧光素和荧光黄CH介导的光毒性的潜在分子物质。
Acridine dyes, fluorescein and lucifer yellow CH are fluorescent photosensitizers used experimentally to selectively stain and photodynamically destroy eukaryotic cells and subcellular structures. We have determined that the mechanism of light‐ and oxygen‐dependent inactivation ofE. coliby these dyes involves oxygen radicals and hydrogen peroxide.All of the dyes oxidized NAD(P)H† under illumination. Superoxide (O2−), detected as the superoxide dismutase (SOD)‐inhibitable reduction of ferricytochrome c, was a major product of the dye sensitized photooxidation.Cationic acridine dyes penetrated the membranes ofE. coliand were photoreduced intracellularly. Reduced dyes diffused back into the medium and mediated the reduction of extracellular ferricytochrome c. The anionic dyes fluorescein and lucifer yellow CH were unable to mediate extracellular cytochrome c reduction, indicating that these dyes were impermeable to theE. colimembranes. Acridine dyes, when illuminated, inhibited the growth ofE. coliin a rich medium, and induced the synthesis of SOD. Fluorescein and lucifer yellow CH did not inhibit growth or induce SOD synthesis because they were unable to enter the cells.Superoxide (O2−) and hydrogen peroxide (H2O2), generated by the enzyme xanthine oxidase were toxic toE. coliB. Inactivation by xanthine oxidase was partially inhibited by exogenous SOD and completely inhibited by exogenous catalase or SOD plus catalase. Similarly, exogenous SOD plus catalase protected against inactivation by acridines and fluorescein‐NADH or lucifer yellow CH‐NADH mixtures. Prior induction of superoxide dismutase and catalase inE. coliB significantly protected cells against a subsequent challenge by illuminated acridine dyes. SOD and catalase preinduction combined with additions of exogenous SOD and catalase completely protectedE. coliB against photodynamic inactivation by acridine yellow. The hydroxyl radical scavengers, dimethyl sulfoxide, sodium benzoate and thiourea, protectedE. coliB against photodynamic inactivation by acridine orange.The results implicate O2−, H2O2, and the hydroxyl radical (OH‐) as underlying molecular agents of the phototoxicity mediated by acridine orange, acridine yellow, fluorescein and lucifer yellow CH.