Collins B, Poehler T O, Bryden W A
Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
Photochem Photobiol. 1995 Sep;62(3):557-60. doi: 10.1111/j.1751-1097.1995.tb02384.x.
Electron paramagnetic resonance is used to detect the formation of free radicals caused by exposure to ultraviolet radiation in chemically untreated rabbit skin. A fast jump in EPR signal level, occurring over a few seconds, is observed immediately after a skin sample is exposed to UV. This is followed by a slower increase toward an elevated steady-state signal over a period of hours as the skin is continuously exposed to a UV light source. Upon cessation of UV light exposure, EPR signal levels undergo an abrupt drop followed by a slower decay toward natural levels. Elevated free radical concentrations following UV exposure are found to persist for several hours in whole skin. These results are consistent with time-resolved EPR measurements of photoinduced radicals in various natural melanins.
电子顺磁共振用于检测未经化学处理的兔皮肤暴露于紫外线辐射后自由基的形成。在皮肤样本暴露于紫外线后，立即观察到EPR信号水平在几秒钟内快速跃升。随着皮肤持续暴露于紫外线光源，在数小时内，EPR信号水平会朝着升高的稳态信号缓慢增加。停止紫外线照射后，EPR信号水平会突然下降，随后朝着自然水平缓慢衰减。发现紫外线照射后升高的自由基浓度在全皮中持续数小时。这些结果与各种天然黑色素中光诱导自由基的时间分辨EPR测量结果一致。
