| ryanodine receptor calcium release channel | Protein complexes that mediate the release of calcium from the sarcoplasmic reticulum in both skeletal and cardiac muscle cells by forming tetrametric complexes. These complexes each then act as a calcium channel. There are three isoforms of the ryr: ryr1, ryr2, and ryr3. Ryr1 is specifically expressed in skeletal muscles and ryr2 in cardiac muscles. Ryr3 is yet another isoform found in non-muscle cells such as neuronal cells. (12 Dec 1998) |
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| potassium channel | Ion channel selective for potassium ions. There are diverse types with different functions, for example: delayed rectifier channels, M channels, A channels, inward rectifier channels, Ca dependent K channels. (18 Nov 1997) |
| single channel recording | Variant of patch clamp technique. (18 Nov 1997) |
| slow channel-blocking agent | calcium channel-blocking agent |
| sodium channel | <neurology, physiology> The protein responsible for electrical excitability of neurons. A transmembrane ion channel, containing an aqueous pore around 0.4nm diameter, with a negatively charged region internally (the selectivity filter) to block passage of anions. The channel is voltage gated: it opens in response to a small depolarisation of the cell (usually caused by an approaching action potential), by a multistep process. Around 1000 sodium ions pass in the next millisecond, before the channel spontaneously closes (an event with single step kinetics). The channel is then refractory to further depolarisations until returned to near the resting potential. There are around 100 channels per square micron in unmyelinated axons, in myelinated axons, they are concentrated at the nodes of Ranvier. The sodium channel is the target of many of the deadliest neurotoxins. (18 Nov 1997) |
| delayed rectifier channel | <physiology> The potassium selective ion channels of axons, so called because they change the potassium conductance with a delay after a voltage step. The name is used to denote any axon like K channel. Various roles for example regulation of pacemaker potentials, generation of bursts of action potentials or generation of long plateaus on action potentials. (18 Nov 1997) |
| double-channel catheter | A catheter with two lumens, allowing irrigation and aspiration. Synonym: two-way catheter. (05 Mar 2000) |
| transnexus channel | A hexagonal 15-20A |
| ligand-gated channel | A class of ion channel's whose ionic permeability is regulated by cell membrane receptors that respond to specific extracellular chemical signals. (05 Mar 2000) |
| Alfven ion cyclotron instability | <radiobiology> An electromagnetic microinstability near the ion cyclotron frequency, driven by the ion loss cone in a mirror device. Acronym: AIC (13 Nov 1997) |
| aquo-ion | A hydrated ion; an ion containing one or more water molecules; e.g., Cu(H2O)42+. (05 Mar 2000) |
| central metal ion | <chemistry> The metal ion to which the ligands are attached at the centre of a coordination complex. (09 Oct 1997) |
| gram-ion | <chemistry> The weight in grams of an ion that is equal to the sum of the atomic weights of the atoms making up the ion. (05 Mar 2000) |
| chromatography, ion exchange | Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins. (12 Dec 1998) |
| mobile ion carrier | <chemistry> A molecule that allows ions to cross lipid bilayers. There are two classes: carriers and channels. Carriers, like valinomycin, form cage like structures around specific ions, diffusing freely through the hydrophobic regions of the bilayer. Channels, like gramicidin, form continuous aqueous pores through the bilayer, allowing ions to diffuse through. See: ion channels. (18 Nov 1997) |
| ion channel |
A protein-coated pore in a cell membrane that selectively regulates the diffusion of ions into and out of the cell. An ion channel switches between open and closed when the protein undergoes a conformational change. For more information see Ions cannot cross membranes (University of Washington, USA). (*PDF file)
출처: www.science.org.au/nova/077/077glo.htm
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| ion channel |
Channel in a cell's surface membrane that controls the flow of ions into the cell. Usually specific for certain ions like sodium or potassium.
출처: www.becomehealthynow.com/popups/120.html
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| ion channel |
An integral membrane protein that provides for the regulated transport of a specific ions across a membrane.
출처: www.exchemistry.com/glossary.html
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| ion channel disease |
A group of diseases marked clinically by muscular weakness, absent muscle tone, or episodic muscular paralysis. The diseases are caused by congenital defects in the cell membrane proteins that move ions into and out of the ce
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