Which of the following blocks voltage-gated sodium channels?
Sodium channel blockers are used in the treatment of cardiac arrhythmia. They are classified as "Type I" in the Vaughan Williams classification. Class I antiarrhythmic agents interfere with the (Na ) channel. Class I agents are grouped by their effect on the Na channel and by their effect on cardiac action potentials. Class I agents are called Membrane Stabilizing Agents. 'Stabilizing' refers to the decrease of excitogenicity of the plasma membrane affecte…
Sodium channels are integral membrane proteins that form ion channels conducting sodium ions (Na ) through a cell's plasma membrane. They belong to the superfamily of cation channels and can be classified according to the trigger that opens the channel for such ions i.e. either a voltage-change ("voltage-gated" "voltage-sensitive" or "voltage-dependent" sodium channel; also called "VGSCs" or "Nav channel") or a binding of a substance (a ligand) to the channel (ligand-gated sodium channels).
Sodium channel blocker - Wikipedia
Voltage-gated ion channel - Wikipedia
For example TTX can bind and inactivate voltage-gated sodium channels despite the fact that TTX is much larger and chemically different than sodium ions. Given the disparities in size and chemical properties between TTX and a sodium ion this is an example of structure being used to block usually specific channels .
Tetrodotoxin is a sodium channel blocker. It inhibits the firing of action potentials in neurons by binding to the voltage-gated sodium channels in nerve cell membranes and blocking the passage of sodium ions (responsible for the rising phase of an action potential) into the neuron. This prevents the nervous system from carrying messages and ...
Saxitoxin is a neurotoxin that acts...
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