Abstract
Neuromuscular blocking of thiamine and its derivatives upon sciatic nerve-sartorius muscle preparation of cold blooded animals was observed.
Thiamine, cocarboxylase (TDP) and pyrithiamine as well as oxythiamine blocked the neuromuscular transmission. Their critical concentrations were about 0.005 M and their blocking times were several decades of minute. From these results, it can be presumed that their action on the neuromuscular transmission must be quite independent of their coenzymatic activities. Derivatives of thiamine in thiol form had also the blocking action. Therefore, the quaternary nitrogen does not play a leading role in the neuromuscular blocking action of thiamine and its derivatives.
