ion channel


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i·on chan·nel

a specific macromolecular protein pathway, with an aqueous "pore," which traverses the lipid bilayer of a cell's plasma membrane and maintains or modulates the electrical potential across this barrier by allowing the controlled influx or exit of small inorganic ions such as Na+, K+, Cl-, and Ca2+. It plays an important role in propagation of the action potential in neurons, but also may control transduction of extracellular signals and contraction in muscle cells. In general, ion channels are characterized by their selectivity for certain ions, their specific regulation or gating of these ions, and their specific sensitivity to toxins.

ion channel

n.
A pathway through a protein molecule or complex in a cell membrane that modulates the electrical potential across the membrane by controlling the passage of small inorganic ions into and out of the cell.

ion channel

A protein that spans the lipid bilayer of the cell membrane and regulates the movement of charged particles (e.g., electrolytes) into and out of cells.
See also: channel

ion

an atom or group of atoms having a positive (cation) or negative (anion) electric charge by virtue of having gained or lost one or more electrons. Substances forming ions are electrolytes.

ion channel
see channel.
dipolar ion
zwitterion.
hydrogen ion
the positively charged hydrogen atom (H+), present to excess in acid solutions.
ion pair
the pair of ions created when an atom has had an electron removed by ionizing radiation.
ion pump
see calcium pump, sodium pump.
ion trapping
a strategy for treatment of poisonings based on the principle that cell membranes are less permeable to ionized compounds. With knowledge of the characteristics of the toxin, treatment can be given to alter the acid-base balance in favor of ionization.
References in periodicals archive ?
L] denote sodium, potassium and leakage ion channel conductance, respectively.
Since the GABAerginc system is an important factor in asthma and other disease states, direct ion channel current measurements are an important technique for the laboratory.
Waxman's research has shown even more potent ramifications for the role of ion channel dysfunction in MS, by demonstrating a strong association between sodium channel abnormalities and nerve fiber damage in mice with the MS-like disorder EAE.
The glutamate binds inside the clamshell and the ion channel opens, the researchers report.
The receivers consisted of ion channels - proteins that act as gateways for electrically charged particles.
HIV-I gp120 and chemokines activate ion channels in primary macrophages through CCR5 and CXCR4 stimulation.
The stretch-activated ion channel blocker gadolinium also blocks L-type calcium channels in isolated ventricular myocytes of the guinea-pig.
The Lipoparticle technology overcomes many of the challenges of conventional electrophysiological approaches for screening ion channel targets, which have largely been limited to studies with live cells or reconstituted lipid bilayers," said Dr.
Early in the course of the disease, synaptic function is impaired so drugs that target this previously unexplored ion channel could have the potential to improve symptoms of the disease.
The authors have organized the forty-three chapters that make up the main body of their text in five sections devoted to basic concepts, ion channel methods, ion channel families, ion channel regulation, and ion channel physiology and diseases.
Correlating ion channel expression with altered function and disregulated signalling pathways during the development of OA will provide a better understanding of mechanisms controlling disease progression and will contribute to the understanding of cartilage degeneration.