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Methyl parathion activation by a partially purified rat brain fraction.
- Source :
-
Toxicology letters [Toxicol Lett] 1996 Sep; Vol. 87 (1), pp. 53-60. - Publication Year :
- 1996
-
Abstract
- Organophosphorus pesticides are one of the most commonly used insecticide classes. They act through a potent inhibition of acetylcholinesterase (AChE). Many of them must undergo transformation into the corresponding oxon analogs to inhibit AChE. This study showed that a brain tissue subfraction transformed methyl parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) in vitro. Methyl parathion activation was assayed by solvent extraction of the products followed by HPLC and GC-MS analyses and, indirectly, by the inhibition of AChE present in the incubation mixture. The lack of impairment of AChE after 2 h of incubation of the brain subfraction with methyl parathion and, alternatively, with NADPH, CO, SKF 525-A, piperonyl butoxide or nitrogen indicated that this brain subfraction transformed methyl parathion without the involvement of a mixed-function oxidative pathway. The results from HPLC analysis did not show a peak corresponding to methyl paraoxon (O,O-dimethyl O-p-nitrophenylphosphate), but showed the production of an unidentified peak which eluted nearby standard methyl parathion (retention times of 10.65 and 8.86 min, respectively). GC-MS analysis suggested that the unidentified product could be a methyl parathion isomer.
- Subjects :
- Acetylcholinesterase analysis
Animals
Biotransformation
Chromatography, Gas
Chromatography, High Pressure Liquid
Cytochrome P-450 Enzyme Inhibitors
Cytochrome P-450 Enzyme System metabolism
Gas Chromatography-Mass Spectrometry
In Vitro Techniques
Mass Spectrometry
Rats
Brain metabolism
Cholinesterase Inhibitors metabolism
Insecticides pharmacokinetics
Methyl Parathion pharmacokinetics
Subjects
Details
- Language :
- English
- ISSN :
- 0378-4274
- Volume :
- 87
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Toxicology letters
- Publication Type :
- Academic Journal
- Accession number :
- 8701445
- Full Text :
- https://doi.org/10.1016/0378-4274(96)03704-6