[Effect of armin on synaptic transmission in frog neuromuscular preparations].
The action of armin, an organophosphorus inhibitor of cholinesterases, on synaptic transmission parameters was studied by means of intracellular registration of end plate potentials and currents (EPP and EPC) in the frog. On 10-minute exposure the increase in the temporary parameters became manifest provided the drug was administered at a concentration of 10(-6) g/ml and over. EPC reversal potential and cholinoreceptor sensitivity to armin did not change substantially. At a concentration of 10-(-8) g/ml armin exerted a potentiating effect on the frequency of miniature EPP and quantum composition of EPP, while that effect was not related to armin anticholinesterase activity. The presynaptic acetylcholine release was suppressed by high concentration of armin (10(-5) g/ml). Under the conditions cited there was a decrease in the depot of the available transmitter quanta in nerve terminals.
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001138:Armin / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009045:Motor Endplate / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D009435:Synaptic Transmission / Q000187:drug effects*
D009943:Organophosphorus Compounds; D001138:Armin; D000109:Acetylcholine
Vliianie armina na sinapticheskuiu peredachu v nervno-myshechnom preparate liagushki.