Page last updated: 2024-10-24

sodium channel activity

Definition

Target type: molecularfunction

Enables the facilitated diffusion of a sodium ion (by an energy-independent process) involving passage through a transmembrane aqueous pore or channel without evidence for a carrier-mediated mechanism. [GOC:BHF, GOC:mtg_transport, GOC:pr, ISBN:0815340729]

Sodium channels are integral membrane proteins responsible for mediating the flow of sodium ions (Na+) across cell membranes. This activity plays a critical role in a wide range of cellular processes, including:

* **Action potential generation and propagation:** Sodium channels are essential for the initiation and conduction of action potentials, the electrical signals that travel along nerve and muscle cells. When a neuron or muscle cell is stimulated, sodium channels open, allowing Na+ ions to flow into the cell. This influx of positive charge depolarizes the membrane, triggering an action potential.

* **Muscle contraction:** In muscle cells, sodium channels are involved in the coupling of electrical excitation to mechanical contraction. Action potentials arriving at the neuromuscular junction trigger the release of acetylcholine, which binds to receptors on the muscle cell membrane. This binding event opens sodium channels, leading to depolarization and muscle contraction.

* **Sensory perception:** Sodium channels are crucial for the detection of sensory stimuli, such as touch, temperature, and pain. Sensory neurons contain sodium channels that open in response to specific stimuli, generating action potentials that are transmitted to the brain for processing.

* **Cardiac function:** Sodium channels are involved in the electrical activity of the heart, controlling the rate and rhythm of heartbeats. Disruptions in sodium channel function can lead to heart arrhythmias.

* **Neurotransmitter release:** Sodium channels play a role in the release of neurotransmitters at synapses, the junctions between nerve cells. Action potentials arriving at the presynaptic terminal trigger the opening of sodium channels, which contribute to the depolarization necessary for neurotransmitter release.

The molecular mechanism of sodium channel activity involves a series of conformational changes in the protein structure. Sodium channels consist of a single polypeptide chain with four domains, each containing six transmembrane segments. The pore region, formed by the S5 and S6 transmembrane segments of each domain, acts as a selective filter for Na+ ions. The opening and closing of the pore is regulated by a voltage sensor located in the S4 transmembrane segments of each domain. When the membrane potential becomes more positive, the voltage sensor moves, triggering a conformational change in the pore that allows Na+ ions to flow through the channel. The channel then rapidly inactivates, closing the pore and preventing further Na+ influx. This inactivation process is essential for the proper function of sodium channels and the generation of action potentials.'
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Proteins (7)

ProteinDefinitionTaxonomy
cGMP-gated cation channel alpha-1A cGMP-gated cation channel alpha-1 that is encoded in the genome of cow. [OMA:Q00194, PRO:DNx]Bos taurus (cattle)
Transient receptor potential cation channel subfamily M member 4A transient receptor potential cation channel subfamily M member 4 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8TD43]Homo sapiens (human)
Sodium channel protein type 9 subunit alphaA sodium channel protein type 9 subunit alpha that is encoded in the genome of mouse. [OMA:Q62205, PRO:DNx]Mus musculus (house mouse)
Acid-sensing ion channel 3An acid-sensing ion channel 3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9UHC3]Homo sapiens (human)
Transient receptor potential cation channel subfamily M member 4A transient receptor potential cation channel subfamily M member 4 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8TD43]Homo sapiens (human)
Sodium channel protein type 7 subunit alphaA sodium channel protein type 7 subunit alpha that is encoded in the genome of human. [PRO:WCB, UniProtKB:Q01118]Homo sapiens (human)
Transient receptor potential cation channel subfamily M member 2A transient receptor potential cation channel subfamily M member 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O94759]Homo sapiens (human)

Compounds (34)

CompoundDefinitionClassesRoles
2-aminoethoxydiphenyl borate2-aminoethoxydiphenyl borate: is a novel membrane-penetrable modulator and transient receptor potential channel blocker; structure in first source; do not confuse with 2-APB cpd

2-aminoethoxydiphenylborane : An organoboron compound that is diphenylborane in which the borane hydrogen is replaced by a 2-aminoethoxy group.
organoboron compound;
primary amino compound
calcium channel blocker;
IP3 receptor antagonist;
potassium channel opener
amiodaroneamiodarone : A member of the class of 1-benzofurans that is 1-benzofuran substituted by a butyl group at position 2 and a 4-[2-(diethylamino)ethoxy]-3,5-diiodobenzoyl group at position 3. It is a cardiovascular drug used for the treatment of cardiac dysrhythmias.

Amiodarone: An antianginal and class III antiarrhythmic drug. It increases the duration of ventricular and atrial muscle action by inhibiting POTASSIUM CHANNELS and VOLTAGE-GATED SODIUM CHANNELS. There is a resulting decrease in heart rate and in vascular resistance.
1-benzofurans;
aromatic ketone;
organoiodine compound;
tertiary amino compound
cardiovascular drug
amitriptylineamitriptyline : An organic tricyclic compound that is 10,11-dihydro-5H-dibenzo[a,d][7]annulene substituted by a 3-(dimethylamino)propylidene group at position 5.

Amitriptyline: Tricyclic antidepressant with anticholinergic and sedative properties. It appears to prevent the re-uptake of norepinephrine and serotonin at nerve terminals, thus potentiating the action of these neurotransmitters. Amitriptyline also appears to antagonize cholinergic and alpha-1 adrenergic responses to bioactive amines.
carbotricyclic compound;
tertiary amine
adrenergic uptake inhibitor;
antidepressant;
environmental contaminant;
tropomyosin-related kinase B receptor agonist;
xenobiotic
chlorpromazinechlorpromazine : A substituted phenothiazine in which the ring nitrogen at position 10 is attached to C-3 of an N,N-dimethylpropanamine moiety.

Chlorpromazine: The prototypical phenothiazine antipsychotic drug. Like the other drugs in this class chlorpromazine's antipsychotic actions are thought to be due to long-term adaptation by the brain to blocking DOPAMINE RECEPTORS. Chlorpromazine has several other actions and therapeutic uses, including as an antiemetic and in the treatment of intractable hiccup.
organochlorine compound;
phenothiazines;
tertiary amine
anticoronaviral agent;
antiemetic;
dopaminergic antagonist;
EC 3.4.21.26 (prolyl oligopeptidase) inhibitor;
phenothiazine antipsychotic drug
cifenlinediarylmethane
clotrimazoleconazole antifungal drug;
imidazole antifungal drug;
imidazoles;
monochlorobenzenes
antiinfective agent;
environmental contaminant;
xenobiotic
econazole1-{2-(4-chlorobenzyloxy)-2-(2,4-dichlorophenyl)ethyl}imidazole : A member of the class of imidazoles that is 1-(2,4-dichlorophenyl)-2-(imidazol-1-yl)ethanol in which the hydroxyl hydrogen is replaced by a 4-chlorobenzyl group.

econazole : A racemate composed of equimolar amounts of (R)- and (S)-econazole. Used (as its nitrate salt) to treat skin infections such as athlete's foot, jock itch, ringworm and other fungal skin infections.

Econazole: An imidazole derivative that is commonly used as a topical antifungal agent.
dichlorobenzene;
ether;
imidazoles;
monochlorobenzenes
flufenamic acidflufenamic acid : An aromatic amino acid consisting of anthranilic acid carrying an N-(trifluoromethyl)phenyl substituent. An analgesic and anti-inflammatory, it is used in rheumatic disorders.

Flufenamic Acid: An anthranilic acid derivative with analgesic, anti-inflammatory, and antipyretic properties. It is used in musculoskeletal and joint disorders and administered by mouth and topically. (From Martindale, The Extra Pharmacopoeia, 30th ed, p16)
aromatic amino acid;
organofluorine compound
antipyretic;
EC 1.14.99.1 (prostaglandin-endoperoxide synthase) inhibitor;
non-narcotic analgesic;
non-steroidal anti-inflammatory drug
haloperidolhaloperidol : A compound composed of a central piperidine structure with hydroxy and p-chlorophenyl substituents at position 4 and an N-linked p-fluorobutyrophenone moiety.

Haloperidol: A phenyl-piperidinyl-butyrophenone that is used primarily to treat SCHIZOPHRENIA and other PSYCHOSES. It is also used in schizoaffective disorder, DELUSIONAL DISORDERS, ballism, and TOURETTE SYNDROME (a drug of choice) and occasionally as adjunctive therapy in INTELLECTUAL DISABILITY and the chorea of HUNTINGTON DISEASE. It is a potent antiemetic and is used in the treatment of intractable HICCUPS. (From AMA Drug Evaluations Annual, 1994, p279)
aromatic ketone;
hydroxypiperidine;
monochlorobenzenes;
organofluorine compound;
tertiary alcohol
antidyskinesia agent;
antiemetic;
dopaminergic antagonist;
first generation antipsychotic;
serotonergic antagonist
imipramineimipramine : A dibenzoazepine that is 5H-dibenzo[b,f]azepine substituted by a 3-(dimethylamino)propyl group at the nitrogen atom.

Imipramine: The prototypical tricyclic antidepressant. It has been used in major depression, dysthymia, bipolar depression, attention-deficit disorders, agoraphobia, and panic disorders. It has less sedative effect than some other members of this therapeutic group.
dibenzoazepineadrenergic uptake inhibitor;
antidepressant;
EC 3.4.21.26 (prolyl oligopeptidase) inhibitor
mefenamic acidmefenamic acid : An aminobenzoic acid that is anthranilic acid in which one of the hydrogens attached to the nitrogen is replaced by a 2,3-dimethylphenyl group. Although classed as a non-steroidal anti-inflammatory drug, its anti-inflammatory properties are considered to be minor. It is used to relieve mild to moderate pain, including headaches, dental pain, osteoarthritis and rheumatoid arthritis.

Mefenamic Acid: A non-steroidal anti-inflammatory agent with analgesic, anti-inflammatory, and antipyretic properties. It is an inhibitor of cyclooxygenase.
aminobenzoic acid;
secondary amino compound
analgesic;
antipyretic;
antirheumatic drug;
EC 1.14.99.1 (prostaglandin-endoperoxide synthase) inhibitor;
environmental contaminant;
non-steroidal anti-inflammatory drug;
xenobiotic
mexiletinemexiletine : An aromatic ether which is 2,6-dimethylphenyl ether of 2-aminopropan-1-ol.

Mexiletine: Antiarrhythmic agent pharmacologically similar to LIDOCAINE. It may have some anticonvulsant properties.
aromatic ether;
primary amino compound
anti-arrhythmia drug
nifedipineNifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.C-nitro compound;
dihydropyridine;
methyl ester
calcium channel blocker;
human metabolite;
tocolytic agent;
vasodilator agent
niflumic acidNiflumic Acid: An analgesic and anti-inflammatory agent used in the treatment of rheumatoid arthritis.aromatic carboxylic acid;
pyridines
nitrendipinenitrendipine : A dihydropyridine that is 1,4-dihydropyridine substituted by methyl groups at positions 2 and 6, a 3-nitrophenyl group at position 4, a ethoxycarbonyl group at position 3 and a methoxycarbonyl group at position 5. It is a calcium-channel blocker used in the treatment of hypertension.

Nitrendipine: A calcium channel blocker with marked vasodilator action. It is an effective antihypertensive agent and differs from other calcium channel blockers in that it does not reduce glomerular filtration rate and is mildly natriuretic, rather than sodium retentive.
C-nitro compound;
dicarboxylic acids and O-substituted derivatives;
diester;
dihydropyridine;
ethyl ester;
methyl ester
antihypertensive agent;
calcium channel blocker;
geroprotector;
vasodilator agent
tetracainetetracaine : A benzoate ester in which 4-N-butylbenzoic acid and 2-(dimethylamino)ethanol have combined to form the ester bond; a local ester anaesthetic (ester caine) used for surface and spinal anaesthesia.

Tetracaine: A potent local anesthetic of the ester type used for surface and spinal anesthesia.
benzoate ester;
tertiary amino compound
local anaesthetic
adenosine monophosphateAdenosine Monophosphate: Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position.adenosine 5'-phosphate;
purine ribonucleoside 5'-monophosphate
adenosine A1 receptor agonist;
cofactor;
EC 3.1.3.1 (alkaline phosphatase) inhibitor;
EC 3.1.3.11 (fructose-bisphosphatase) inhibitor;
fundamental metabolite;
micronutrient;
nutraceutical
9-phenanthrol9-phenanthrol : A phenanthrol that is phenanthrene in which a hydrogen attached to a carbon in the central ring has been replaced by a hydroxy group.

9-phenanthrol: an inhibitor of AMP-dependent protein kinase catalytic subunit; structure in first source
phenanthrolTRPM4 channel inhibitor
amilorideamiloride : A member of the class of pyrazines resulting from the formal monoacylation of guanidine with the carboxy group of 3,5-diamino-6-chloropyrazine-2-carboxylic acid.

Amiloride: A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
aromatic amine;
guanidines;
organochlorine compound;
pyrazines
diuretic;
sodium channel blocker
pimozidepimozide : A member of the class of benzimidazoles that is 1,3-dihydro-2H-benzimidazol-2-one in which one of the nitrogens is substituted by a piperidin-4-yl group, which in turn is substituted on the nitrogen by a 4,4-bis(p-fluorophenyl)butyl group.

Pimozide: A diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to HALOPERIDOL for the suppression of vocal and motor tics in patients with Tourette syndrome. Although the precise mechanism of action is unknown, blockade of postsynaptic dopamine receptors has been postulated. (From AMA Drug Evaluations Annual, 1994, p403)
benzimidazoles;
heteroarylpiperidine;
organofluorine compound
antidyskinesia agent;
dopaminergic antagonist;
first generation antipsychotic;
H1-receptor antagonist;
serotonergic antagonist
mexiletine hydrochloridemexiletine hydrochloride : A hydrochloride composed of equimolar amounts of mexiletine and hydrogen chloride.hydrochlorideanti-arrhythmia drug
adenosine diphosphate riboseAdenosine Diphosphate Ribose: An ester formed between the aldehydic carbon of RIBOSE and the terminal phosphate of ADENOSINE DIPHOSPHATE. It is produced by the hydrolysis of nicotinamide-adenine dinucleotide (NAD) by a variety of enzymes, some of which transfer an ADP-ribosyl group to target proteins.ADP-sugarEscherichia coli metabolite;
mouse metabolite
diltiazemdiltiazem : A 5-[2-(dimethylamino)ethyl]-2-(4-methoxyphenyl)-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepin-3-yl acetate in which both stereocentres have S configuration. A calcium-channel blocker and vasodilator, it is used as the hydrochloride in the management of angina pectoris and hypertension.

Diltiazem: A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on membrane functions.
5-[2-(dimethylamino)ethyl]-2-(4-methoxyphenyl)-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepin-3-yl acetateantihypertensive agent;
calcium channel blocker;
vasodilator agent
sertindolesertindole : A phenylindole that is 1H-indole which is substituted on the nitrogen by a p-chlorophenyl group, at position 5 by chlorine, and at position 3 by a piperidin-4-yl group, which is itself substituted on the nitrogen by a 2-(2-oxoimidazolidin-1-yl)ethyl group.heteroarylpiperidine;
imidazolidinone;
organochlorine compound;
organofluorine compound;
phenylindole
alpha-adrenergic antagonist;
H1-receptor antagonist;
second generation antipsychotic;
serotonergic antagonist
mibefradilMibefradil: A benzimidazoyl-substituted tetraline that selectively binds and inhibits CALCIUM CHANNELS, T-TYPE.tetralinsT-type calcium channel blocker
tedisamiltedisamil : A member of the class of diazabicyclononanes that is (1s,5s)-3,7-diazaspiro[bicyclo[3.3.1]nonane-9,1'-cyclopentane] in which the hydrogens at positions 3 and 7 are replaced by cyclopropylmethyl groups. It is a potassium channel blocker and an antiarrhythmic agent currently currently in development for the treatment of atrial fibrillation.
uk 68798aromatic ether;
sulfonamide;
tertiary amino compound
anti-arrhythmia drug;
potassium channel blocker
4-amylcinnamoylanthranilic acid4-amylcinnamoylanthranilic acid: phospholipase A2 inhibitor

N-(p-amylcinnamoyl)anthranilic acid : An amidobenzoic acid that is anthranilic acid in which one of the anilino hydrogens is replaced by a 4-pentylcinnamoyl group. It is a transient receptor potential (TRP) channel blocker and phospholipase A2 (PLA2) inhibitor.
amidobenzoic acid;
cinnamamides;
secondary carboxamide
EC 3.1.1.4 (phospholipase A2) inhibitor;
TRP channel blocker
3,4-dihydro-5-(4-(1-piperidinyl)butoxy)-1(2h)-isoquinolinone
tetrodotoxin
cnv1014802vixotrigine: a sodium channel blocker
scalaradialscalaradial : A scalarane sesterterpenoid with formula C27H40O4. It is a natural product found in the marine sponges Spongia officinalis and Cacospongia mollior, and exhibits anti-inflammatory activity.

scalaradial: RN refers to the (5alpha,12alpha,17abeta)-isomer; a marine natural product isolated from the sponge Cacospongia sp.; structure given in first source
acetate ester;
carbotetracyclic compound;
dialdehyde;
enal;
scalarane sesterterpenoid
animal metabolite;
anti-inflammatory agent;
apoptosis inducer;
EC 3.1.1.4 (phospholipase A2) inhibitor;
marine metabolite;
TRP channel blocker
saxitoxinsaxitoxin : An alkaloid isolated from the marine dinoflagellates and cyanobacteria that causes paralytic shellfish poisoning.

Saxitoxin: A compound that contains a reduced purine ring system but is not biosynthetically related to the purine alkaloids. It is a poison found in certain edible mollusks at certain times; elaborated by GONYAULAX and consumed by mollusks, fishes, etc. without ill effects. It is neurotoxic and causes RESPIRATORY PARALYSIS and other effects in MAMMALS, known as paralytic SHELLFISH poisoning.
alkaloid;
carbamate ester;
guanidines;
ketone hydrate;
paralytic shellfish toxin;
pyrrolopurine
cyanotoxin;
marine metabolite;
neurotoxin;
sodium channel blocker;
toxin
ajmaline