Target type: molecularfunction
Enables the transmembrane transfer of a monoatomic cation by a channel that opens when a change in the osmolarity occurs in the extracellular space of the cell in which the cation channel resides. [PMID:18279313]
Osmolarity-sensing monoatomic cation channel activity refers to the ability of a channel protein to respond to changes in the osmolarity of the surrounding environment by altering its permeability to monoatomic cations, such as sodium (Na+), potassium (K+), and calcium (Ca2+). These channels play a crucial role in maintaining cell volume and osmotic balance by regulating the movement of ions across the cell membrane.
When the osmolarity of the extracellular fluid changes, the cell membrane experiences osmotic stress. In hypertonic conditions, where the extracellular fluid has a higher solute concentration than the intracellular fluid, water moves out of the cell, leading to cell shrinkage. Conversely, in hypotonic conditions, where the extracellular fluid has a lower solute concentration than the intracellular fluid, water moves into the cell, leading to cell swelling.
Osmolarity-sensing monoatomic cation channels respond to these osmotic changes by altering their permeability to cations. In hypertonic conditions, these channels typically open, allowing an influx of cations into the cell. This influx of cations increases the intracellular osmotic pressure, counteracting the outward movement of water and preventing cell shrinkage. In hypotonic conditions, these channels typically close, reducing the influx of cations and preventing excessive cell swelling.
The molecular mechanisms underlying osmolarity sensing in these channels vary. Some channels are directly activated by changes in membrane tension, while others are regulated by specific intracellular signaling pathways. For example, some channels are activated by the binding of specific osmolytes, such as sugars or amino acids, while others are regulated by changes in the phosphorylation state of the channel protein.
The specific mechanisms by which osmolarity-sensing monoatomic cation channels contribute to cell volume regulation and osmotic balance depend on the type of channel and the cell type in which it is expressed. For example, some channels are involved in the regulation of renal water reabsorption, while others play a role in the regulation of neuronal excitability.
In summary, osmolarity-sensing monoatomic cation channel activity is a critical process for maintaining cell volume and osmotic balance. These channels respond to changes in osmolarity by altering their permeability to cations, thereby regulating the movement of ions across the cell membrane and counteracting the effects of osmotic stress.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Sodium channel protein type 7 subunit alpha | A sodium channel protein type 7 subunit alpha that is encoded in the genome of human. [PRO:WCB, UniProtKB:Q01118] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| amiodarone | amiodarone : 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 |
| amitriptyline | amitriptyline : 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 |
| chlorpromazine | chlorpromazine : 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 |
| cifenline | diarylmethane | ||
| haloperidol | haloperidol : 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 |
| imipramine | imipramine : 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. | dibenzoazepine | adrenergic uptake inhibitor; antidepressant; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor |
| mexiletine | mexiletine : 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 |
| nifedipine | Nifedipine: 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 |
| nitrendipine | nitrendipine : 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 |
| tetracaine | tetracaine : 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 |
| pimozide | pimozide : 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 |
| diltiazem | diltiazem : 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 acetate | antihypertensive agent; calcium channel blocker; vasodilator agent |
| sertindole | sertindole : 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 |
| mibefradil | Mibefradil: A benzimidazoyl-substituted tetraline that selectively binds and inhibits CALCIUM CHANNELS, T-TYPE. | tetralins | T-type calcium channel blocker |
| tedisamil | tedisamil : 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 68798 | aromatic ether; sulfonamide; tertiary amino compound | anti-arrhythmia drug; potassium channel blocker | |
| tetrodotoxin | |||
| cnv1014802 | vixotrigine: a sodium channel blocker | ||
| saxitoxin | saxitoxin : 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 |