Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatic microsomal drug-metabolizing enzyme activities, cytochrome content, delta-aminolevulinic acid (ALA) synthetase and heme oxygenase activities were studied in rats bearing ascitic tumors AH 13, AH 66 and AH 414 and a primary, 3-methylcholanthrene (3-MC)-induced, tumor. Hepatic microsomal drug-metabolizing enzyme activities and cytochrome content were decreased in rats transplanted intraperitoneally with 1-2 x 10(6) cells of ascitic tumor cell lines AH 13, AH 66 and AH 414. The extent of the decrease of the microsomal cytochrome content and enzyme activities were dependent on the tumor-bearing periods after inoculation. Hepatic microsomal heme oxygenase activity was significantly increased concurrently with the decrease of microsomal drug-metabolizing enzyme activities and cytochrome content. Hepatic ALA synthetase was not changed appreciably in these tumor-bearing rats. Similar alterations of microsomal enzyme content and activities were observed in the livers of rats transplanted subcutaneously with AH 66 tumor cells and in rats bearing a primary tumor initiated by the subcutaneous injection of 3-MC. When the tumor was surgically removed from the rats bearing AH 66 subcutaneously, these hepatic microsomal parameters returned to normal levels. Microsomal drug-metabolizing enzyme activities and cytochrome content in these ascitic tumor cells were found to be at very low levels. From these results, if appears that there is an inverse relationship between the increase of microsomal heme oxygenase activity and the decrease of cytochrome P-450 and b5 as well as drug-metabolizing enzymes in the liver of tumor bearing rats.
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PMID:Alterations of hepatic delta-aminolevulinic acid synthetase, heme oxygenase, microsomal cytochrome content and drug metabolism in rats bearing ascitic tumors AH 13, AH 66 and AH 414 and a 3-methylcholanthrene induced tumor. 654 16

5-Aminolevulinic acid (5-ALA), a commonly used photosensitizer in photodynamic detection (PDD) and therapy (PDT), is converted in situ to the established photosensitizer protoporphyrin IX (PpIX) via the heme biosynthetic pathway. To extend 5-ALA-PDT application, we evaluated the PpIX fluorescence induced by exogenous 5-ALA in various veterinary tumors and treated canine and feline tumors. 5-ALA-PDD sensitivity and specificity in the whole sample group for dogs and cats combined were 89.5 and 50%, respectively. Notably, some small tumors disappeared upon 5-ALA-PDT. Although single PDT application was not curative, repeated PDT+/-chemotherapy achieved long-term tumor control. We analyzed the relationship between intracellular PpIX concentration and 5-ALA-PDT in vitro cytotoxicity using various primary tumor cells and determined the correlation between intracellular PpIX concentration and 5-ALA transporter and metabolic enzyme mRNA expression levels. 5-ALA-PDT cytotoxicity in vitro correlated with intracellular PpIX concentration in carcinomas. Ferrochelatase mRNA expression levels strongly negatively correlated with PpIX accumulation, representing the first report of a correlation between mRNA expression related to PpIX accumulation and PpIX concentration in canine tumor cells. Our findings suggested that the results of 5-ALA-PDD might be predictive for 5-ALA-PDT therapeutic effects for carcinomas, with 5-ALA-PDT plus chemotherapy potentially increasing the probability of tumor control in veterinary medicine.
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PMID:Efficacy of 5-Aminolevulinic Acid in Photodynamic Detection and Photodynamic Therapy in Veterinary Medicine. 3095 82