Baker A, Kanofsky J R
Research Service, Edward Hines, Jr., Department of Veterans Affairs Hospital, Hines, IL 60141.
Photochem Photobiol. 1993 Apr;57(4):720-7. doi: 10.1111/j.1751-1097.1993.tb02944.x.
Time-resolved measurements were made of near-infrared emission from 5-(N-hexadecanoyl)amino-eosin-labeled L1210 leukemia cells following pulsed-laser excitation. The cells were suspended in phosphate-buffered saline made with deuterium oxide solvent. A significant fraction of the emission occurring 10-80 microseconds after the laser pulse was due to singlet oxygen. This singlet-oxygen emission is believed to result from singlet oxygen generated near the cell-membrane surface, where 5-(N-hexadecanoyl)amino eosin is known to concentrate, and then diffusing out into the buffer. The intensity and the kinetics of the experimentally observed singlet-oxygen emission were in excellent agreement with the predictions of a theoretical one-dimensional model of singlet-oxygen diffusion and quenching. During the 10-80 microseconds time period studied, most of the singlet oxygen was located in the buffer. Thus, the use of water-soluble singlet-oxygen quenchers, such as histidine, provide one means of separating the singlet-oxygen emission from other sources of light during this time interval.
在脉冲激光激发后，对5-(N-十六烷酰基)氨基曙红标记的L1210白血病细胞的近红外发射进行了时间分辨测量。细胞悬浮在用氧化氘溶剂配制的磷酸盐缓冲盐水中。激光脉冲后10 - 80微秒出现的很大一部分发射是由于单线态氧。这种单线态氧发射被认为是由细胞膜表面附近产生的单线态氧导致的，已知5-(N-十六烷酰基)氨基曙红会在该表面聚集，然后扩散到缓冲液中。实验观察到的单线态氧发射的强度和动力学与单线态氧扩散和猝灭的理论一维模型的预测非常吻合。在所研究的10 - 80微秒时间段内，大部分单线态氧位于缓冲液中。因此，使用水溶性单线态氧猝灭剂，如组氨酸，提供了一种在该时间间隔内将单线态氧发射与其他光源分离的方法。
