Endlicher, E. and Ruemmele, Petra and Hausmann, F. and Krieg, R. and Knuechel, Ruth and Rath, H. and Schoelmerich, Juergen and Messmann, Helmut (2001) Protoporphyrin IX distribution following local application of 5-aminolevulinic acid and its esterified derivatives in the tissue layers of the normal rat colon. BRITISH JOURNAL OF CANCER, 85 (10). pp. 1572-1576. ISSN 0007-0920
Full text not available from this repository. (Request a copy)Abstract
Photodynamic diagnosis and especially therapy after sensitization with 5-aminolevulinic acid (ALA) is hampered by limitations of uptake and distribution of ALA due to its hydrophilic nature. Chemical modification of ALA into its more lipophilic esters seems to be promising to overcome these problems. The aim of the present study was to investigate the comparative kinetics of protoporphyrin IX (PPIX) fluorescence in rat colonic tissue after topical application of ALA and its esterified derivatives, ALA-hexylester (h-ALA), ALA-methylester (mALA) and ALA-benzylester (b-ALA). Fluorescence intensity induced by PPIX in normal colonic tissue was quantified using fluorescence microscopy at 1, 2, 4, 6 and 8 h after sensitization. Mucosa exhibited higher fluorescence levels compared to the underlying submucosa. or smooth muscle. Peak fluorescence intensities were seen 4 h after local sensitization with 86.0 mol ml(-1) ALA (513 +/- 0.57 counts per pixel), 6.6 mol ml(-1) m-ALA (508 +/- 35.50) and 4.8 mol ml(-1) h-ALA (532 +/- 128.80), and 6 h after sensitization with 4.6 mol ml(-1) b-ALA (468 +/- 190.27). A 13-18 times lower concentration of ALA esters was required for fluorescence intensities reached with ALA alone. A similar degree of the fluorescence ratio between mucosa and muscularis (5-6:1) was detected for ALA and its derivatives. The time point of the maximum value of this ratio was consistent with peak fluorescence levels for ALA and each ALA-ester. The clinical feasibility and the advantages of topical ALA ester-based fluorescence for detection of malignant and premalignant lesions need further investigations. (C) 2001 Cancer Research Campaign.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | DELTA-AMINOLEVULINIC-ACID; PHOTODYNAMIC THERAPY; BLADDER-CANCER; BARRETTS-ESOPHAGUS; IN-VITRO; FLUORESCENCE; ESTERS; CELLS; ALA; DIAGNOSIS; 5-aminolevulinic acid; 5-aminolevulinic esters; protoporphyrin IX; fluorescence; colon |
| Subjects: | 500 Science > 540 Chemistry & allied sciences 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Innere Medizin I Medicine > Lehrstuhl für Pathologie Chemistry and Pharmacy > Institut für Anorganische Chemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 24 Nov 2021 09:35 |
| Last Modified: | 24 Nov 2021 09:35 |
| URI: | https://pred.uni-regensburg.de/id/eprint/40936 |
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