Kinetics of protoporphyrin IX formation in rat oral mucosa and skin after application of 5-aminolevulinic acid and its methylester.
The kinetics of accumulation of protoporphyrin IX (PpIX) after topical application of 5-aminolevulinic acid (ALA) and its methylester (5-aminolevulinic acid methylester [ALA-Me]) was studied on rat oral mucosa. The accumulation of PpIX in mucosa and skin after intravenous injection of ALA and ALA-Me was also studied. The elimination rate of PpIX was dependent on drug and dose as well as on administration route. Application of ALA on rat oral mucosa and skin caused a systemic effect with PpIX building up in remote skin sites not exposed to the drugs. No such systemic effect was seen after application of ALA-Me either in mucosa or on skin. Intravenous injection of the drugs (0.2 g/kg) leads to more fluorescence in the skin than topical application of the drug (20%). For mucosa, the opposite is true. Maximal PpIX fluorescence appeared later after application of high concentrations of the drugs (around 8 h for 5% and 20% wt/wt) than after application of low concentrations (around 3-5 h for 1% and 2% wt/wt).
Kristiansson
Stefan
S
Department of Otolaryngology, Orebro University Hospital, Orebro, Sweden. stefan.kristiansson@orebroll.se
Juzeniene
Asta
A
Juzenas
Petras
P
Iani
Vladimir
V
Löfgren
Lennart
L
Moan
Johan
J
D000622:Aminolevulinic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005453:Fluorescence; D007275:Injections, Intravenous; D007700:Kinetics; D009061:Mouth Mucosa / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D011524:Protoporphyrins / Q000096:biosynthesis* / Q000737:chemistry; D051381:Rats; D011923:Rats, Nude; D012867:Skin / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D011524:Protoporphyrins; C114767:delta-aminolevulinic acid methyl ester; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX