Non-selective cation channels and oxidative stress- induced cell swelling
Necrosis is considered as a non-specific form of cell death that induces tissue inflammation and is preceded by cell swelling. This increase in cell volume has been ascribed mainly to defective outward pumping of Na+ caused by metabolic depletion and/or to increased Na+ influx via membrane transport...
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| Autores principales: | , , , , |
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| Lenguaje: | English |
| Publicado: |
Sociedad de Biología de Chile
2002
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| Materias: | |
| Acceso en línea: | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602002000200013 |
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| Sumario: | Necrosis is considered as a non-specific form of cell death that induces tissue inflammation and is preceded by cell swelling. This increase in cell volume has been ascribed mainly to defective outward pumping of Na+ caused by metabolic depletion and/or to increased Na+ influx via membrane transporters. A specific mechanism of swelling and necrosis driven by the influx of Na+ through nonselective cation channels has been recently proposed (<A HREF="#2">Barros et al., 2001a</A>). We have characterized further the properties of the nonselective cation channel (NSCC) in HTC cells. The NSCC shows a conductance of ~18 pS, is equally permeable to Na+ and K+, impermeant to Ca2+, requires high intracellular Ca2+ as well as low intracellular ATP for activation and is inhibited by flufenamic acid. Hydrogen peroxide induced a significant increase in cell volume that was dependent on external Na+. We propose that the NSCC, which is ubiquitous though largely inactive in healthy cells, becomes activated under severe oxidative stress. The ensuing Na+ influx initiates via positive feedback a series of metabolic and electrolytic disturbances, resulting in cell death by necrosis |
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