Back to Search
Start Over
Porphyrin biosynthesis in human Barrett's oesophagus and adenocarcinoma after ingestion of 5-aminolaevulinic acid.
- Source :
- British Journal of Cancer; 8/15/2000, Vol. 83 Issue 4, p539-543, 5p
- Publication Year :
- 2000
-
Abstract
- 5-Aminolaevulinic acid (ALA)-induced porphyrin biosynthesis, which is used for ALA-based photodynamic therapy (ALA-PDT), was studied in tissues of 10 patients with Barrett's oesophagus (BE) and adenocarcinoma of the oesophagus (AC) undergoing oesophagectomy at a mean time interval of 6.7 h after the ingestion of ALA (60 mg kg(-1)). In BE, AC, squamous epithelium (SQ) and gastric cardia, the activities of the haem biosynthetic enzymes porphobilinogen deaminase (PBG-D) and ferrochelatase (FC) and the PDT power index--the ratio between PBG-D and FC in BE and AC in comparison with SQ--were determined before ALA ingestion. Following ALA administration, ALA, porphobilinogen, uroporphyrin I and PPIX were determined in tissues and plasma. The PDT power index did not predict the level of intracellular accumulation of PPIX found at 6.7 h. In BE, there was no selectivity of PPIX accumulation compared to SQ, whereas in half of patients with AC selectivity was found. Higher haem biosynthetic enzyme activities (i.e. PBG-D) and lower PPIX precursor concentrations were found in BE and AC compared to SQ. It is therefore possible that PPIX levels will peak at earlier time intervals in BE and AC compared to SQ. [ABSTRACT FROM AUTHOR]
- Subjects :
- PORPHYRINS
ESOPHAGUS diseases
ENZYME metabolism
ADENOCARCINOMA
AMINO acids
COMPARATIVE studies
ESOPHAGEAL tumors
HETEROCYCLIC compounds
RESEARCH methodology
MEDICAL cooperation
ORAL drug administration
PHOTOCHEMOTHERAPY
PHOTOSENSITIZERS
RESEARCH
TRANSFERASES
EVALUATION research
BARRETT'S esophagus
METALLOPORPHYRINS
PHARMACODYNAMICS
Subjects
Details
- Language :
- English
- ISSN :
- 00070920
- Volume :
- 83
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- British Journal of Cancer
- Publication Type :
- Academic Journal
- Accession number :
- 8876915
- Full Text :
- https://doi.org/10.1054/bjoc.2000.1300