Abstract
1. Alloxan and its auto-oxidation product hydrogen peroxide (H2O2) irreversibly depolarize insulinoma cells by opening a non-selective cation channel. The channel opened is characterized by a linear current-voltage relation with a conductance of approximately 70 pS and very slow kinetics (of the order of seconds). 2. Cells are protected against the alloxan-induced channel opening and consequent cell depolarization by the presence of H2O2 and hydroxyl radical scavengers. 3. The free radical-activated non-selective cation channel is not operative in isolated patches but can be activated by the application of beta-NAD+ to the cytoplasmic aspect of the membrane.
| Original language | English |
|---|---|
| Pages (from-to) | 59-66 |
| Number of pages | 8 |
| Journal | Journal of Physiology |
| Volume | 501 |
| Issue number | ( Pt 1) |
| Publication status | Published - 15 May 1997 |
Keywords
- Animals
- Niacinamide
- Thiourea
- Hydrogen Peroxide
- Insulinoma
- Islets of Langerhans
- Reactive Oxygen Species
- Rats
- Patch-Clamp Techniques
- Tumor Cells, Cultured
- Cell Polarity
- Cysteine
- Alloxan
- Free Radical Scavengers
- Membrane Potentials