title: Repeated small doses of a neurotoxic organophosphate. Monitoring of neurotoxic esterase in brain and spinal cord.
abstract: The effects of small repeated oral doses of mono-2-cresyl diphenyl phosphate (MOCP, 2.5 mg/kg/day) on hen brain and spinal cord neurotoxic esterase (NTE) were measured. The enzyme levels were depressed to about 40% and 55% of normal respectively and maintained at that level for 8 weeks. No clinical and only doubtful histological signs of neuropathy were detected. Neuropathy could be precipitated by depressing the level to < 20% either with a single high dose (50 mg/kg), or by an increase of the repeated dose level to 5 mg/kg/day. There was no correlation between inhibition of NTE in the nervous tissue and the "NTE-like" activity in lymphocytes. "NTE-like" activity in spleen was consistently inhibited but to a lesser extent than that in the brain or spinal cord. Brain AChE and BuChE were not affected.
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002091:Butyrylcholinesterase / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002645:Chickens; D003408:Cresols / Q000633:toxicity*; D005260:Female; D009943:Organophosphorus Compounds / Q000633:toxicity*; D013116:Spinal Cord / Q000201:enzymology*
chemical_list: D003408:Cresols; D009943:Organophosphorus Compounds; C001082:diphenylcresyl phosphate; D002265:Carboxylic Ester Hydrolases; C021859:neurotoxic esterase; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase