Adult vertebrate skeletal muscle sodium channels are responsible for the spread of excitation from the end-plate through the muscle membrane and transverse tubular system that ultimately leads to contraction. These channels can be distinguished from other sodium channels by their sensitivity to both mu-conotoxin and TTX. The mouse satellite muscle cell line MM14 expresses only TTX- and mu-conot...

Synaptotagmin, a synaptic vesicle protein involved in Ca(2+)-regulated exocytosis, displayed direct high affinity interaction with neuronal sodium channels. Monoclonal antibodies directed against synaptotagmins I and II adsorbed in a concentration-dependent and -specific manner [(3)H]saxitoxin prelabeled sodium channels extracted with detergent from nerve endings. Conversely, co-immunoprecipita...

The inhibition of sodium currents by quaternary derivatives of lidocaine was studied in single myelinated nerve fibers. Membrane currents were diminished little by external quaternary lidocaine (QX). QX present in the axoplasm (<0.5 mM) inhibited sodium currents by more than 90%. Inhibition occurred as the sum of a constant, tonic phase and a variable, voltagesensitive phase. The voltage-sensit...

Cultured Schwann cells from sciatic nerves of newborn rabbits and rats have been examined with patch-clamp techniques. In rabbit cells, single sodium and potassium channels have been detected with single channel conductances of 20 pS and 19 pS, respectively. Single sodium channels have a reversal potential within 15 mV of ENa, are blocked by tetrodotoxin, and have rapid and voltage-independent ...

The inhibition of sodium currents by quaternary derivatives of lidocaine was studied in single myelinated nerve fibers. Membrane currents were diminished little by external quaternary lidocaine (QX). QX present in the axoplasm (<0.5 mM) inhibited sodium currents by more than 90%. Inhibition occurred as the sum of a constant, tonic phase and a variable, voltage-sensitive phase. The voltage-sensi...

The inhibition of sodium currents by quaternary derivatives of lidocaine was studied in single myelinated nerve fibers. Membrane currents were diminished little by external quaternary lidocaine (QX). QX present in the axoplasm (<0.5 mM) inhibited sodium currents by more than 90%. Inhibition occurred as the sum of a constant, tonic phase and a variable, voltagesensitive phase. The voltage-sensit...