Selective inhibition of acetylcholinesterase in the cerebellum and hippocampus of mice following an acute treatment with malathion.
Adult male ICR mice were treated by intraperitoneal injection with 250 mg/kg of bodyweight of commercial malathion (a dose corresponding to 1/12 the LD50). After 6 h, acetylcholinesterase (AChE) activity in blood, liver, and six brain regions was determined. A statistically significant inhibition was observed in whole blood (23%), liver (21%), and, in particular, the central nervous system; the greatest degree of AChE inhibition was observed in the cerebellum (45%), followed by the hippocampus (29%). There was no significant change in AChE activity in the caudate putamen, frontal cortex, midbrain, or pons medulla. These results demonstrate that the magnitude of AChE inhibition in peripheral tissues does not accurately reflect the central-inhibitory effects of malathion on AChE activity in specific brain regions.
Center for Environmental and Occupational Risk Analysis and Management, Department of Environmental and Occupational Health, College of Public Health, University of South Florida, Tampa, Florida 33612, USA.
Marek
M
Banasik
Todd
T
Stedeford
Amanda S
AS
Persad
Kunihiro
K
Ueda
Seigo
S
Tanaka
Carlos
C
Muro-Cacho
Raymond D
RD
Harbison
D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D002531:Cerebellum / Q000187:drug effects* / Q000201:enzymology; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D006624:Hippocampus / Q000187:drug effects* / Q000201:enzymology; D007306:Insecticides / Q000633:toxicity*; D008294:Malathion / Q000633:toxicity*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR
D002800:Cholinesterase Inhibitors; D007306:Insecticides; D000110:Acetylcholinesterase; D008294:Malathion