Comparative effect of ALA derivatives on protoporphyrin IX production in human and rat skin organ cultures.
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.
Casas
A
A
CIPYP, CONICET and University of Buenos Aires, Argentina.
Batlle
A M
AM
Butler
A R
AR
Robertson
D
D
Brown
E H
EH
MacRobert
A
A
Riley
P A
PA
D000622:Aminolevulinic Acid / Q000031:analogs & derivatives / Q000494:pharmacology*; D000818:Animals; D005260:Female; D006801:Humans; D008856:Microscopy, Fluorescence; D009924:Organ Culture Techniques; D011524:Protoporphyrins / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000187:drug effects* / Q000378:metabolism
D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX