[Joint action of reversible and irreversible cholinesterase inhibitors on neuromuscular transmission in the rat diaphragm]

Abstract

Presynaptic effect of compound application of the cholinesterase (ChE) inhibitors of the reversible (galanthamine) and the irreversible (armin) after galanthamine pretreatment has been studied on the neuromuscular transmission at the rat diaphragm. The experiment conditions were regarded as a model of the preventive action of the reversible ChE inhibitors against organism poisoning by the irreversible ChE inhibitors. The quantal content of the end plate potentials (EPP) decreases under the compound action of inhibitors. But under these conditions the EPP amplitude at the single nerve stimulation increases as compared with the control one. The pronounced presynaptic depression and the block of the neuromuscular transmission are observed at the repetitive stimulation (10-50 s-1). The preventive action of galanthamine against the armin poisoning does not relate to presynaptic processes.