准分子激光诱导动脉荧光光谱的研究

A Study of Excimer Laser-induced Fluorescence Spectroscopy of Normal and Atherosclerotic Aorta

采用XeCl准分子激光照射兔正常及硬化主动脉内膜面产生荧光光谱,两者均在380nm及450nm处各有一个荧光峰值,在410nm处有一波谷。计算第二峰值与波谷强度比值分别为Ⅰ450/Ⅰ410=1.604±0.093(正常)及1.154±0.026(斑块),这一差别可用来鉴别正常血管壁及斑块。采用四环素、金霉素处理标本后,荧光光谱发生了改变。特别是经金霉素体外处理的斑块,原荧光峰值几乎消失,而在510nm处首次记录到特征性荧光峰,以此可能提高对斑块的鉴别率。

A XeCl excimer laser (308nm) was used to irradiate normal and atherosclerotic aorta of New Zealand rabbits and the fluorescence characteristics were analyzed by using a spectrophotometer. Fluorescence spectroscopy indicated a broad-continuum emission from 308 to 600 nm with two peaks at 380 and 450nm, respectively and a valley at 410 nm for samples of both normal and atherosclerotic aorta. However, the height of the 450 nm peak relative to the valley at 410 nm was different between normal and atherosclerotic samples. The ratio of I450/I410 was 1,604 卤 0.093 for the former and 1,153卤0.026 for the latter. This difference could be used to distinguish normal from atherosclerotic plaque by setting up a critical value of the ratio. Fluorescence spectroscopy, after in vitro treatment of animal aorta samples by using photosensitizer showed that the intensity was weakened for all samples. When tetracycline was used, no special characteristics of fluorescence spectra were observed. When chlortetracycline hydrochloride was used, the peak at 380 nm disappeared and there was a flat peak from 410 to 440 nm for normal aorta. Both peaks at 380 nm and 450 nm disappeared but there was a new peak at 510 nm for atherosclerotic samples which can be used to dif- ferentiate atherosclerotic plaque from normal aorta. Results also showed that tetracycline could improve the function of laser ablation for atherosclerotic plaque but it had no such an effect on normal aorta.