Optimisation of the formation and distribution of protoporphyrin IX in the urothelium: an in vitro approach.
OBJECTIVE
To optimize conditions for photodynamic detection (PDD) and photodynamic therapy (PDT) of bladder carcinoma, urothelial accumulation of protoporphyrin IX (PpIX) and conditions leading to cell photodestruction were studied.


METHODS
Porcine and human bladder mucosae were superfused with derivatives of 5-aminolevulinic acid (ALA). PpIX accumulation and distribution across the mucosa was studied by microspectrofluorometry. Cell viability and structural integrity were assessed by using vital dyes and microscopy.


RESULTS
ALA esters, especially hexyl-ALA, accelerated and regularized urothelial PpIX accumulation and allowed for necrosis upon illumination.


CONCLUSIONS
hexyl-ALA used at micromolar concentrations is the most efficient PpIX precursor for PDD and PDT.
Institute of Physiology, Faculty of Medicine, University of Lausanne, the Federal Institute of Technology, Switzerland.
A
A
Marti
N
N
Lange
H
H
van den Bergh
D
D
Sedmera
P
P
Jichlinski
P
P
Kucera
D000622:Aminolevulinic Acid / Q000494:pharmacology; D000818:Animals; D006801:Humans; D017319:Photosensitizing Agents / Q000493:pharmacokinetics*; D011524:Protoporphyrins / Q000493:pharmacokinetics*; D013552:Swine; D014018:Tissue Distribution; D019459:Urothelium / Q000187:drug effects / Q000378:metabolism*
D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX