Eichler Maor, Lavi Ronit, Friedmann Harry, Shainberg Asher, Lubart Rachel
Department of Chemistry, Bar-Ilan University, Ramat Gan, Israel.
Photomed Laser Surg. 2007 Jun;25(3):170-4. doi: 10.1089/pho.2007.2046.
The aim of this study was to determine the wavelength dependence of light-induced redox reactions in cells, particularly whether there is any contribution by red wavelengths. An additional aim was to assess the potential of 2,2,6,6-tetramethyl piperidine-N-oxyl (TEMPO) as a tool for measuring these redox reactions.
Visible light has been shown to affect cells, and redox reactions, which have been detected previously using spin traps, have been proposed as a mechanism. However, there is little evidence that red light, which is used in most such experiments, is redox active in cells.
Redox activity was observed by measuring the decay of the electron paramagnetic resonance signal of TEMPO that occurs in the presence of illuminated cells. Color filters were used to generate blue, green, and red light, and the decay resulting from these wavelengths was compared to the decay caused by white light.
Shorter wavelengths have a considerably stronger effect than longer wavelengths, although red light has some effect. Creation of reactive oxygen species by red light was confirmed with the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO).
Red light can induce redox reactions in illuminated cells. However, shorter wavelengths are more efficient in this regard. In addition, TEMPO was found to be a more sensitive probe than DMPO for detecting light-induced cellular redox reactions.
本研究旨在确定细胞中光诱导氧化还原反应的波长依赖性，特别是红光波长是否有任何作用。另一个目的是评估2,2,6,6-四甲基哌啶-N-氧基（TEMPO）作为测量这些氧化还原反应工具的潜力。
可见光已被证明会影响细胞，先前使用自旋捕获剂检测到的氧化还原反应被认为是一种机制。然而，几乎没有证据表明在大多数此类实验中使用的红光在细胞中具有氧化还原活性。
通过测量在有光照细胞存在时TEMPO的电子顺磁共振信号衰减来观察氧化还原活性。使用滤色片产生蓝光、绿光和红光，并将这些波长引起的衰减与白光引起的衰减进行比较。
尽管红光有一定作用，但较短波长的光比较长波长的光具有更强得多的效应。用自旋捕获剂5,5-二甲基-1-吡咯啉-N-氧化物（DMPO）证实了红光可产生活性氧。
红光可在受照细胞中诱导氧化还原反应。然而，在这方面较短波长的光更有效。此外，发现TEMPO是比DMPO更灵敏的用于检测光诱导细胞氧化还原反应的探针。
