Abstract
Samples of human and rat skin in short-term organ culture exposed to ALA or a range of hydrophobic derivatives were examined for their effect on the accumulation of protoporphyrin IX (PpIX) measured using fluorescence spectroscopy. With the exception of carbobenzoyloxy-D-phenylalanyl-5-ALA-ethyl ester the data presented indicate that, in normal tissues, ALA derivatives generate protoporphyrin IX more slowly than ALA, suggesting that they are less rapidly taken up and/or converted to free ALA. However, the resultant depot effect may lead to the enhanced accumulation of porphyrin over long exposure periods, particularly in the case of ALA-methyl ester or ALA-hexyl ester, depending on the applied concentration and the exposed tissue. Addition of the iron chelator, CP94, greatly increased PpIX accumulation in human skin exposed to ALA, ALA-methyl ester and ALA-hexyl ester. The effect in rat skin was less marked.
Original language | English |
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Pages (from-to) | 1525-1532 |
Number of pages | 8 |
Journal | British Journal of Cancer |
Volume | 80 |
Publication status | Published - Jul 1999 |
Keywords
- ALA
- PDT
- ALA derivatives
- ALA esters
- iron chelators
- CP94
- DELTA-AMINOLEVULINIC-ACID
- 5-AMINOLEVULINIC ACID
- PHOTODYNAMIC THERAPY
- INDUCED PORPHYRIN
- TREATED CELLS
- ACCUMULATION
- PHOTODESTRUCTION
- FLUORESCENCE
- ENHANCEMENT
- TRANSPORT