title: Membrane-bound and soluble esterase activities in various hen brain regions after diisopropyl phosphorofluoridate and trichlorfon treatment.
abstract: Acetylcholinesterase, neurotoxic esterase, and nonspecific esterase activities were studied in subcellular fractions obtained from homogenates of forebrain, cerebellum, and brainstem areas of hen brain. The hens were given a single, oral dose (1.0 mg/kg of Dyflos (diisopropyl phosphorofluoridate) or 100 mg/kg of trichlorfon (dimethyl -2,2,2-trichloro-1-hydroxyethylphosphonate). The animals were killed 24 hr after dosing. The level of neurotoxic esterase and soluble nonspecific esterase activities were consistent from region to region; however, acetylcholinesterase activity among the brain regions varied significantly. Both organophosphorus compounds produced definite inhibition of acetylcholinesterase. The cerebellar acetylcholinesterase activity was the most susceptible to organophosphorus ester-induced inhibition. A marked inhibition of neurotoxic esterase (70-80%) was produced by diisopropyl phosphorofluoridate in all areas. Trichlorfon produced little or no inhibition of neurotoxic esterase (0-10%). Little variation in soluble nonspecific esterase activity (alpha -naphthyl acetate) was noted between the three brain regions studied. Both diisopropyl phosphorofluoridate and trichlorfon failed to significantly alter soluble nonspecific esterase activity among the brain regions.
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D002265:Carboxylic Ester Hydrolases / Q000032:analysis; D002645:Chickens; D004950:Esterases / Q000032:analysis*; D005260:Female; D007531:Isoflurophate / Q000633:toxicity*; D014236:Trichlorfon / Q000633:toxicity*
chemical_list: D007531:Isoflurophate; D014236:Trichlorfon; D004950:Esterases; D002265:Carboxylic Ester Hydrolases; C021859:neurotoxic esterase; D000110:Acetylcholinesterase