Phototransformation of ALA-induced protoporphyrin IX (PPIX) in carcinoma cells and of exogenous PPIX in cells and solutions

The fluorescence bleaching and photoproduct formation of PPIX was investigated in Ehrlich ascite carcinoma (EAC) cells (ALA induced and exogenous applied) as well as in micelles (Triton X-100) and DMSO. In all the cases fluorescence bleaching of PPIX occurs but the photoproduct formation is quite different. Besides the rapid fluorescence bleaching of the ALA induced PPIX in EAC cells the formation of a water soluble porphyrin with fluorescence maxima at 616 nm and 678 nm (coproporphyrin) was observed. In the presence of the triplet- and oxygen-quencher (beta) -carotene the fluorescence bleaching of PPIX can be reduced.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.