Biophotonics Group of Laser Research Center, Faculty of Physics, Vilnius University, Sauletekio 9, Bldg. 3, Vilnius LT-10222, Lithuania.
J Photochem Photobiol B. 2013 Feb 5;119:15-21. doi: 10.1016/j.jphotobiol.2012.11.008. Epub 2012 Dec 3.
The sensitization of inflamed knee tissues with endogenous porphyrins was studied by means of fluorescence spectroscopy in an experimental model of rabbit rheumatoid monoarthritis after intraarticular (i.a.) or intravenous (i.v.) injections of 5-aminolevulinic acid (ALA) or ALA methyl ester (ALA-Me). Fluorescence measurements in vivo on the skin of the inflamed knee joint showed the dominance of protoporphyrin IX (PpIX). The highest fluorescence intensity was registered 2h after i.a. injection of ALA and ALA-Me. Comparative analysis of the PpIX fluorescence spectra ex vivo revealed that more PpIX accumulated in the tissues of the inflamed joint than in the tissues of the control joint, and that ALA-Me induced about five times more PpIX in the inflamed synovium than ALA. Meanwhile, the cartilages of the inflamed and control knee joints also accumulated water-soluble porphyrins. Thus, in vivo and ex vivo spectroscopic assessment of endogenous porphyrins in rabbit rheumatoid arthritis tissues implied that the injection of ALA is more appropriate for the diagnostics of inflammation due to the higher PpIX fluorescence intensity on the skin surface, while ALA-Me is more appropriate for the therapeutic applications due to the higher and more selective accumulation of PpIX in the inflamed synovium.
研究了内源性卟啉在兔类风湿性单关节炎实验模型中对炎症性膝关节组织的敏化作用，方法是通过荧光光谱法在关节内（i.a.）或静脉内（i.v.）注射 5-氨基乙酰丙酸（ALA）或 ALA 甲酯（ALA-Me）后进行。对炎症性膝关节皮肤进行的体内荧光测量显示原卟啉 IX（PpIX）占主导地位。在 i.a.注射 ALA 和 ALA-Me 后 2 小时记录到最高荧光强度。对离体 PpIX 荧光光谱的比较分析表明，在炎症关节组织中积累的 PpIX 多于对照关节组织，并且 ALA-Me 在炎症滑膜中诱导的 PpIX 比 ALA 多约五倍。同时，炎症和对照膝关节的软骨也积累了水溶性卟啉。因此，在兔类风湿关节炎组织中对内源性卟啉进行体内和离体光谱评估表明，由于皮肤表面的 PpIX 荧光强度更高，因此注射 ALA 更适合用于炎症的诊断，而由于 PpIX 在炎症滑膜中的更高和更选择性积累，ALA-Me 更适合用于治疗应用。
