Influence of the external concentration of potassium ions on functioning of voltage-dependent potassium channels in GH3 cells
Grishchenko, A. V. ; Berezetskaya, N. M. ; Weinreb, G. E. ; Kononenko, N. I. ; Sedova, M. B.
Springer
Published 1995
Springer
Published 1995
| ISSN: |
1573-9007
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| Source: |
Springer Online Journal Archives 1860-2000
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| Topics: |
Medicine
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| Notes: |
Abstract The patch-clamp technique in a whole-cell configuration was used to study the influence of the external concentration of potassium ions on the characteristics of the voltage-dependent potassium current in the plasma membrane of GH3 cells (a cell line isolated from the rat pituitary body tumor). The [K+] out shift from 5 to 100 mM induced a monotonic increase in potassium current with a constant difference between the testing potential and potassium equilibrium potential. The dependence of an activation time constant, τ n , and a steady-state activation,n∞, of the potassium current on [K+] out is of a distinct non-monotononic character with the extremum at 20 mM. Our experiments and theoretical speculations allow us to suppose that the interaction of potassium ions with slowly relaxing charged channel-forming protein groups induced the observed effects.
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| Type of Medium: |
Electronic Resource
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| URL: |