[Effect of anticholinesterases on acetylcholinesterase distribution in the human and animal brain (cytochemical study)].

With the use of quantitative histochemistry and cytochemistry methods the localization of acetylcholinesterase in the brain of man and animals in cases of acute poisoning with organophosphorus compounds was studied. In the brain of animals poisoned with chlorophos the activity of the enzyme, according to cytophotometric findings, dropped 2 or 3 times, this drop being more pronounced in the neuropile. In the human brain, the drop of the acetylcholinesterase activity caused by organophosphorus compounds was the most pronounced in the neuropile and the neurons of the cortex, caudate nucleus and hypothalamus. The cytochemical examinations of the enzyme in the cases of poisoning showed absence of the sediment on the basal membrane of the capillaries and the membranes of the nervous fibres and synapses. However, acetylcholinesterase was found to remain active in some neurons at the nuclear membrane and in the endoplasmic reticulum (presence of the sediment in the form of individual granules or discrete zones). Probability of the acetylcholinesterase activity inhibition mainly in the outer (in relation to the neuron) barrier systems and possibility of reparative processes in the neurons are discussed.