The effect of poneratoxin on neuromuscular transmission in the rat diaphragm.
The effect of the ant venom neuropeptide--poneratoxin (PoTX)--on neuromuscular transmission in rat diaphragm tissue was studied by means of intracellular recordings of spontaneous miniature endplate potentials (MEPPs) and of nerve evoked endplate potentials (EPPs). A 2 microM concentration of PoTX caused a pronounced but transient increase in MEPPs frequency. Moreover, within the first few minutes of PoTX administration, the area, rise time and half decay time of MEPPs gradually decreased, reaching steady values after 15-20 min. The alteration of the area, rise time and half decay time of EPPs after PoTX application was similar to that observed for MEPPs. We conclude that PoTX affects neuromuscular transmission in rat tissue, and suggest that PoTX could exert both pre- and postsynaptic effects.
Hendrich
Andrzej B
AB
Department of Biophysics, Wrocław Medical University, T. Chałubińskiego 10, 50-368 Wrocław, Poland.
Mozrzymas
Jerzy W
JW
Konopińska
Danuta
D
Scuka
Maria
M
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000862:Ant Venoms / Q000494:pharmacology*; D001000:Ants; D002799:Cholinergic Fibers; D003964:Diaphragm / Q000294:innervation*; D004594:Electrophysiology; D005071:Evoked Potentials / Q000187:drug effects; D019476:Insect Proteins; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009045:Motor Endplate / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology*; D009498:Neurotoxins / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology
D000862:Ant Venoms; D019476:Insect Proteins; D009479:Neuropeptides; D009498:Neurotoxins; C072588:poneratoxin