In Vitro Covalent Binding of New Brain Tracer,Para 125 I-Amphetamine,to Rat Liver and Lung Microsomes

ABSTRACT

Butachlor action on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities in central nervous tissue of the snail Pita globosa was assayed following the method of ELLMAN et al¹, in vitro by adding butachlor directly (10–100 μ moles), to tissue homogenates and in in vivo by exposing the snails to sub-lethal concentration (26.6 ppm) and taking out the tissue for experimentation at different intervals (3, 6,12, 24 and 48 h) of exposure. The enzyme activities decreased in a dose-dependent manner in vitro, and up to 12–24 h in vivo after which they showed recovery towards the control. The inhibition of cholinesterases by butachlor in vitro indicates a direct action of the herbicide on these enzymes. Presumably butachlor exercises its neurotoxic effects through cholinergic impairment in a way similar to that of organophosphates and carbamates.