Time course of neostigmine action on the endplate response.
Miniature endplate currents (MEPCs) were focally recorded in frog sartorius muscle. In the presence of 3 microM neostigmine, the amplitude of MEPCs increased, but later, after 45-60 min of treatment, a decrease of the amplitude towards the initial levels appeared. The pronounced lengthening of the falling phase of MEPCs, which accompanied the increased amplitude, suggests that at the beginning the effect is mainly ascribed to cholinesterase inhibition. The final decreased amplitude of MEPC showed a shortening of the time course instead. This suggests that also a direct effect on endplate receptors is involved.
Deana
A
A
Department of Biology, University of Trieste, Italy.
Scuka
M
M
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D009045:Motor Endplate / Q000187:drug effects*; D009132:Muscles / Q000294:innervation; D009388:Neostigmine / Q000494:pharmacology*; D011893:Rana esculenta
D002800:Cholinesterase Inhibitors; D009388:Neostigmine; D000109:Acetylcholine