The effects of intracisternal sarin and pyridine-2-aldoxime methyl methanesulphonate in anesthetized dogs.

Dogs poisoned by the anticholinesterase sarin could be saved by intravenous administration of atropine sulphate together with a suitable oxime. The central effects of intracisternal sarin were respiratory paralysis and vasomotor stimulation. The problem arose as to whether the oxime, being a quaternary nitrogen compound, could enter the brain from the blood, and could have a central action on the paralysed respiration. The methyl methanesulphonate of pyridine-2-aldoxime administered intracisternally, after sarin poisoning by the same route, was ineffective; atropine, given intravenously, was effective. The central and peripheral effects of sarin were thus reversed by the atropine-oxime therapy, the central effects by atropine, the peripheral by the oxime.