[The effects of 2-chloro-4-bromo-alpha-methylcinnamic acid on the neuromuscular transmission of toad].
The effects of 2-chloro-4-bromo-alpha-methylcinnamic acid sodium (SC1001 Na) on neuromuscular transmission were tested by means of intracellular recordings in isolated sciatic nerve-sartorius preparations of toad. The results were: (1) at a concentration of 0.1mmol/L, SC1001 Na had no effect on end-plate potential (EPP); at a concentration of 1 mmol/L, SC1001 Na reduced the amplitude of the EPP significantly, and the paired-pulse facilitation was also decreased; at a concentration of 10mmol/L, SC1001 Na blocked the EPP completely; (2) the 0.1 mmol/L and 1mmol/L groups of drug had no effect on the resting potential of the toad muscle fibers; the resting potential was reduced significantly by SC1001Na at the concentration of 10mmol/L, the action of 10mmol/L drug was irreversible. These results suggest that SC1001 Na may block the neuromuscular transmission of toad, and the blocking effect might be mainly due to a presynaptic mechanism.
Geng
Z
Z
Liu
Y
Y
Guo
L
L
Wu
L
L
Chai
H
H
Xie
Y
Y
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D002023:Bufo bufo; D005260:Female; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009045:Motor Endplate / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology*; D012964:Sodium / Q000494:pharmacology*; D009435:Synaptic Transmission / Q000187:drug effects*
D000927:Anticonvulsants; C072444:SC 1001; D012964:Sodium