Photobleaching of arterial fluorescent compounds: Characterization of elastin, collagen and cholesterol time-resolved spectra during prolonged ultraviolet irradiation
Photobleaching of arterial fluorescent compounds: Characterization of elastin, collagen and cholesterol time-resolved spectra during prolonged ultraviolet irradiation
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DOI：
10.1111/j.1751-1097.1999.tb03352.x
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发表时间：
1999-06-01
影响因子：
3.3
通讯作者：
Maarek, JMI
中科院分区：
文献类型：
--
作者：
Marcu, L;Grundfest, WS;Maarek, JMI
为了研究动脉壁主要荧光化合物的光漂白，我们用氮激光脉冲在560 s激发期间重复测量弹性蛋白、胶原和胆固醇的时间分辨荧光。使用三种注量率水平：0.72、7.25和21.75 μ W/mm（2）。的荧光强度和时间分辨的荧光衰减常数的辐射相关的变化，其特征在于在390，430和470 nm的发射。当输送的能量密度为4 mJ/mm（2）时，390 nm处的荧光强度降低25-35%，这是动脉壁荧光研究中的常见值。胆固醇荧光光漂白最多，弹性蛋白荧光光漂白最少。光漂白是最强烈的在390毫米和最不强烈的在470 nm，使三种化合物的发射光谱显着扭曲的光漂白。当能量密度低于4 mJ/mm（2）时，时间分辨衰减常数和荧光寿命不会因照射而改变。与光漂白相关的光谱失真使动脉壁荧光在弹性蛋白、胶原蛋白和胆固醇组织含量方面的解释复杂化。使用不被光漂白改变的发射的时间依赖性特征应该增加通过荧光光谱分析的动脉壁的准确性。
To study the photobleaching of the main fluorescent compounds of the arterial wall, we repeatedly measured the time-resolved fluorescence of elastin, collagen and cholesterol during 560 s of excitation with nitrogen laser pulses, Three fluence rate levels were used: 0.72, 7.25 and 21.75 mu W/mm(2). The irradiation-related changes of the fluorescence intensity and of the time-resolved fluorescence decay constants were characterized for the emission at 390, 430 and 470 nm. The fluorescence intensity at 390 nm decreased by 25-35% when the fluence delivered was 4 mJ/mm(2), a common value in fluorescence studies of the arterial wall. Cholesterol fluorescence photobleached the most, and elastin fluorescence photobleached the least. Photobleaching was most intense at 390 mm and least intense at 470 nm such that the emission spectra of the three compounds were markedly distorted by photobleaching. The time-resolved decay constants and the fluorescence lifetime were not altered by irradiation when the fluence was below 4 mJ/mm(2), The spectral distortions associated with photobleaching complicate the interpretation of arterial wall fluorescence in terms of tissue content in elastin, collagen and cholesterol. Use of the time-dependent features of the emission that are not altered by photobleaching should increase the accuracy of arterial wall analysis by fluorescence spectroscopy.