Selective Inhibitors of Fatty Acid Amide Hydrolase Relative to Neuropathy Target Esterase and Acetylcholinesterase: Toxicological Implications
Autor: | John E. Casida, Daniel K. Nomura, Yoffi Segall, Susan E. Sparks, Gary B. Quistad |
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Rok vydání: | 2002 |
Předmět: |
Male
Insecticides Oleamide Neuropathy target esterase Pharmacology Toxicology Amidohydrolases Mice chemistry.chemical_compound Organophosphorus Compounds Fatty acid amide hydrolase Cannabinoid Receptor Modulators medicine Animals Enzyme Inhibitors Behavior Animal biology Cannabinoids Neurotoxicity Brain Anandamide Sulfinic Acids medicine.disease Acetylcholinesterase Endocannabinoid system nervous system chemistry Biochemistry Mechanism of action biology.protein lipids (amino acids peptides and proteins) Cholinesterase Inhibitors medicine.symptom Carboxylic Ester Hydrolases psychological phenomena and processes |
Zdroj: | Toxicology and Applied Pharmacology. 179:57-63 |
ISSN: | 0041-008X |
DOI: | 10.1006/taap.2001.9342 |
Popis: | Fatty acid amide hydrolase (FAAH) plays an important role in nerve function by regulating the action of endocannabinoids (e.g., anandamide) and hydrolyzing a sleep-inducing factor (oleamide). Several organophosphorus pesticides and related compounds are shown in this study to be more potent in vivo inhibitors of mouse brain FAAH than neuropathy target esterase (NTE), raising the question of the potential toxicological relevance of FAAH inhibition. These FAAH-selective compounds include tribufos and (R)-octylbenzodioxaphosphorin oxide with delayed neurotoxic effects in mice and hens plus several organophosphorus pesticides (e.g., fenthion) implicated as delayed neurotoxicants in humans. The search for a highly potent and selective inhibitor for FAAH relative to NTE for use as a toxicological probe culminated in the discovery that octylsulfonyl fluoride inhibits FAAH by 50% at 2 nM in vitro and 0.2 mg/kg in vivo and NTE is at least 100-fold less sensitive in each case. More generally, the studies revealed 12 selective in vitro inhibitors for FAAH (mostly octylsulfonyl and octylphosphonyl derivatives) and 9 for NTE (mostly benzodioxaphosphorin oxides and organophosphorus fluoridates). The overall in vivo findings with 16 compounds indicate the expected association of AChE inhibition with acute or cholinergic syndrome and >70% brain NTE inhibition with delayed neurotoxic action. Surprisingly, 75-99% brain FAAH inhibition does not lead to any overt neurotoxicity or change in behavior (other than potentiation of exogenous anandamide action). Thus, FAAH inhibition in mouse brain does not appear to be a primary target for organophosphorus pesticide-induced neurotoxic action (cholinergic or intermediate syndrome or delayed neurotoxicity). |
Databáze: | OpenAIRE |
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