Influence of administration methods on the accumulation of ALA-induced Pp-IX in mouse tongue tumors.
OBJECTIVE
5-Aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) has been used as a photosensitizer in photodynamic therapy (PDT) for oral cancer. This study investigates the optimal method of administrating ALA by analyzing PpIX fluorescence in tongue tumor tissue.


METHODS
Protoporphyrin IX intensities in the mouse (C3H)-transplanted tongue cancer (NR-S1) were compared with those in normal tongue after intraperitoneal (i.p.), oral (p.o.) or topical administration of ALA. Tongues were sampled at various times after ALA administration. PpIX intensities were obtained from frozen sections of each sample by using a spectrophotometer.


RESULTS
Protoporphyrin IX intensity in the tumor group peaked at 3 h after the i.p. and 5 h after the p.o. administration of ALA, and these levels were about twice as high as those in the normal group. Maximum PpIX accumulation in the tongue tumor tissue was seen at 5 h after p.o. administration of ALA. In contrast, the topical administration of 20% ALA cream was associated with the lowest PpIX accumulation in the tumor throughout the experiments.


CONCLUSIONS
These results suggested that p.o. administration of ALA was the most effective method in ALA-PDT for oral cancer.
Ogasawara
T
T
Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, School of Medicine, Faculty of Medical Sciences, University of Fukui, Matsuoka, Fukui, Japan. ogasa@fmsrsa.fukui-med.ac.jp
Miyoshi
N
N
Sano
K
K
Kitagawa
Y
Y
Yamada
T
T
Ogawa
T
T
Miyauchi
K
K
Kinoshita
H
H
D000284:Administration, Oral; D000287:Administration, Topical; D000622:Aminolevulinic Acid / Q000008:administration & dosage*; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy*; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009368:Neoplasm Transplantation; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D011524:Protoporphyrins / Q000008:administration & dosage*; D013050:Spectrometry, Fluorescence; D018709:Statistics, Nonparametric; D014062:Tongue Neoplasms / Q000188:drug therapy*
D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX