Several scorpion toxins have been shown to exert their neurotoxic effects by a direct interaction with voltage-dependent sodium channels. Both classical scorpion alpha-toxins such as Lqh II from Leiurus quiquestratus hebraeus and alpha-like toxins as toxin III from the same scorpion (Lqh III) competitively interact for binding on receptor site 3 of insect sodium channels. Conversely, Lqh III, w...

This article evaluates the effect of membrane active channel-forming polyene antibiotic (PA) of levorin and its alkyl derivatives on the muscle performance. The membrane channels of muscle cells are capable to transport ions of potassium, sodium, and calcium. In the period of an intensive muscle exercise, the necessity for organic substrates increases and these channels start to work with the g...

Voltage-gated sodium channels (VGSCs) are large transmembrane proteins that conduct sodium ions across the membrane and by doing so they generate signals of communication between many kinds of tissues. They are responsible for the generation and propagation of action potentials in excitable cells, in close collaboration with other channels like potassium channels. Therefore, genetic defects in ...

Much data, including crystallographic, support structural models of sodium and potassium channels consisting of S1-S4 transmembrane segments (the "voltage-sensing domain") clustered around a central pore-forming region (S5-S6 segments and the intervening loop). Voltage gated sodium channels have four non-identical domains which differentiates them from the homotetrameric potassium channels that...

UNLABELLED Propofol decreases muscle tone in the absence of neuromuscular blocking drugs. This effect probably cannot be attributed solely to central nervous depression. We studied the effects of propofol on heterologously expressed skeletal muscle sodium channels. Our hypothesis was that the decrease in muscle tone may partly be attributed to an interaction of propofol with sarcolemmal sodium ...

In this study, we investigated the mechanism that links activation of NMDA receptors to inhibition of voltage-gated sodium channels in isolated catfish cone horizontal cells. NMDA channels were activated in voltage-clamped cells incubated in low calcium saline or dialyzed with the calcium chelator, BAPTA, to determine that calcium influx through NMDA channels is required for sodium channel modu...

Voltage-dependent sodium channels are believed to have evolved from calcium channels at the origin of the nervous system. A search of the genome of a single-celled choanoflagellate (the sister group of animals) identified a gene that is homologous to animal sodium channels and has a putative ion selectivity filter intermediate between calcium and sodium channels. Searches of a wide variety of a...

Voltage-gated sodium channels in the mammalian CNS initiate and propagate action potentials when excitatory inputs achieve threshold membrane depolarization. There are multiple sodium channel isoforms expressed in rat brain (types I, II, III, 6, and NaG). We have constructed a full-length cDNA clone encoding type I and compared the electrophysiological properties of type I (Rat1) and II (Rat2) ...

The functional properties of most sodium channels are too similar to permit identification of specific sodium channel types underlying macroscopic current. Such discrimination would be particularly advantageous in the nervous system in which different sodium channel family isoforms are coexpressed in the same cell. To test whether members of the mu-conotoxin family can discriminate among known ...