suxamethonium (succinyldicholine) as an agonist and channel blocker at
the nicotinic receptor of frog muscle. Journal of Physiology.
428:155-74, 1990:
Suxamethonium (Sux) was a more potent blocker of the open ion channel
than ACh (equilibrium constant about 200 microM); this limited the
maximum open probability to about 0.36 (at 12 degrees C and -120 mV).
Individual channel blockages lasted about 65 microseconds on average.
They appeared to get longer at high agonist concentration; however, a
simulation method was used to show that this effect could be accounted
for by the fact that at higher concentrations there are more openings
that are too brief to be detected. Over the concentration range tested
the effects were described by a simple open channel block mechanism. 4.
No component of brief shut times could be detected other than those
resulting from channel blockages. However, the results suggest that
multiple channel openings (the nachschlag phenomenon) should be rare, so
this is not inconsistent with previous results with other agonists.
