Lack of constitutive and inducible ethoxyresorufin-O-deethylase activity in the liver of suckermouth armored catfish (Hypostomus affinis and Hypostomus auroguttatus, Loricariidae)
| Autor: | D.A. Chapeaurouge, Jonas Perales, Francisco José Roma Paumgartten, Ana C.A.X. De-Oliveira, Thiago E.M. Parente, D.G. Beghini |
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| Rok vydání: | 2009 |
| Předmět: |
Fish Proteins
animal structures food.ingredient Physiology Health Toxicology and Mutagenesis Loricariidae 9 10-Dimethyl-1 2-benzanthracene DMBA 7-Alkoxycoumarin O-Dealkylase Biology Toxicology medicine.disease_cause Biochemistry Substrate Specificity Nile tilapia Mice food Cytochrome P-450 Enzyme System beta-Naphthoflavone Oxazines medicine Cytochrome P-450 CYP1A1 Animals Cytochrome P-450 CYP3A Enzyme Inhibitors Catfishes Micronuclei Chromosome-Defective Benzoflavones Tilapia Cell Biology General Medicine Anatomy biology.organism_classification Molecular biology Trout Oreochromis Kinetics Liver Receptors Aryl Hydrocarbon Enzyme Induction embryonic structures Cytochrome P-450 CYP2B1 Microsomes Liver Aryl Hydrocarbon Hydroxylases human activities Genotoxicity Catfish Mutagens |
| Zdroj: | Comparative biochemistry and physiology. Toxicologypharmacology : CBP. 150(2) |
| ISSN: | 1532-0456 |
| Popis: | We investigated the presence and inducibility of CYP1A in suckermouth catfish (Hypostomus affinis and Hypostomus auroguttatus, Loricariidae), tilapia (Oreochromis niloticus, Cichlidae) and mice (Mus musculus, Muridae). Alkoxyresorufin-O-dealkylases (EROD, MROD, PROD and BROD) were detected and proved to be inducible (beta-naphthoflavone, BNF or dimethylbenz[a]anthracene, DMBA, 50 mg/kg bw ip) in liver microsomes from tilapia and mice. In loricariids, alkoxyresorufin-O-dealkylases were either undetectable (MROD/EROD) or very low (PROD/BROD), and so they remained after treatment with BNF or DMBA. Ethoxycoumarin-O-deethylase (ECOD) was recorded in all species and proved not to be inducible by BNF or DMBA. In loricariids and tilapia, ECOD was not depressed by a concentration of alpha-naphthoflavone (CYP1A-inhibitor) that markedly depressed EROD in tilapia. A CYP1A-like protein was detected by a monoclonal antibody in rats, mice and tilapia, but not in loricariids. A polyclonal antibody, however, detected a CYP1A-like protein in liver microsomes of loricariids. Suckermouth catfish, rats, mice and tilapia express a protein reactive with a polyclonal antibody against trout CYP3A. Loricariids and tilapia exhibited marked genotoxic responses (enhanced incidence of micronucleated erythrocytes) following treatment DMBA (50 mg/kg bw ip), a promutagen activated by CYP1A/1B. Therefore, although not exhibiting EROD, a CYP1A-mediated activity, loricariids converted DMBA into its genotoxic metabolites. Our findings suggest that the CYP1A-like protein of locariid catfish recognizes DMBA, but not ethoxyresorufin, as a substrate. |
| Databáze: | OpenAIRE |
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