In vitro study of organophosphorus inactivators of membrane acetylcholinesterase and of reactivating pyridinium-oximes using rat brain slices.

A modified method of Ellman's reaction with a continuous flow was used to study the cerebral cholinesterase activity in its biological environment with rat brain slices including the striatum. Comparative studies were performed under various conditions of flow and substrate concentrations (acetylthiocholine bromide) and with or without formaldehyde fixation. We could thus measure either the inhibition rate of cerebral ChE by paraoxon or MPT or the reactivation rate by some oximes in the presence of substrate and after removing excess inhibitor.