The reduction of a nitroxide spin label as a probe of human blood antioxidant properties
The reduction of a nitroxide spin label as a probe of human blood antioxidant properties
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DOI：
10.1080/1071576021000050410
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发表时间：
2003-01-01
影响因子：
3.3
通讯作者：
Meyerstein, N
中科院分区：
文献类型：
--
作者：
Saphier, O;Silberstein, T;Meyerstein, N
自由基R-的还原动力学。、血源性5-dimethylaminonaphthalene-1-sulfonyl-4-amino-2，2，6，6-tetramethyl-1-piperidine-oxyl，及其成分的电子顺磁共振研究。结果表明，R-。被吸附到膜的外表面，不会渗透到红细胞中。在PBS中的一系列对照实验表明，抗坏血酸是唯一与R-反应的天然还原剂。。观察到的氮氧自由基的一级消失速率k为：k(血)>；k(血)和k(血)与k(血)+k(血浆)一致。结果表明：a.红细胞对R-的还原有催化作用。受到……的影响。自由基的还原速率很高，虽然它不能渗透到细胞中。在人的红细胞中，有一条有效的电子传递途径穿过细胞膜。研究指出，R-。是一种合适的自旋标记，用于测量由抗坏血酸还原所表达的血液中的还原动力学和抗氧化能力。
The kinetics of reduction of the radical R-. , 5-dimethylaminonaphthalene-1-sulfonyl-4-amino-2,2,6,6-tetramethyl-1-piperidine-oxyl, by blood and its components were studied using the EPR technique. The results demonstrate that R-. is adsorbed to the outer surface of the membrane and does not penetrate into the erythrocytes. A series of control experiments in PBS demonstrate that ascorbate is the only natural reducing agent that reacts with R-. . The observed first order rate of disappearance of the nitroxide radical, k , is: k(blood) > k(eryth) > k(plasma) and k(blood) congruent to k(eryth) + k(plasma) . The results demonstrate that:a. The erythrocytes catalyze the reduction of R-. by ascorbate.b. The rate of reduction of the radical is high though it does not penetrate the cells.c. In human erythrocytes there is an efficient electron transfer route through the cell membrane.d. The study points out that R-. is a suitable spin label for measuring the reduction kinetics and antioxidant capacity in blood as expressed by reduction by ascorbate.