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Membrane electrical parameters of normal human red blood cells
Society of General Physiologists Series
|January 1, 1984
Summary
The sodium-potassium (Na/K) pump contributes minimally to the membrane potential (Em) of human red blood cells, with an electrogenic component of only 0.1 to 0.2 mV. This suggests a membrane resistance (Rm) of approximately 1-2 X 10(5) ohm cm2.
Area of Science:
- Physiology
- Biophysics
- Cell Biology
Background:
- The sodium-potassium (Na/K) pump is crucial for maintaining cellular ion gradients.
- Understanding its electrogenic contribution to membrane potential (Em) is vital for cell function.
- Human red blood cells serve as a model system for studying ion transport.
Purpose of the Study:
- To quantify the electrogenic contribution of the Na/K pump to the Em in human red blood cells.
- To estimate the membrane resistance (Rm) of these cells based on pump activity.
Main Methods:
- Measurement of membrane potential (Em) in human red blood cells.
- Quantification of ouabain-sensitive sodium (Na) efflux to determine pump current.
- Calculation of electrogenic component and membrane resistance (Rm).
Main Results:
- The Na/K pump's contribution to Em in human red blood cells with normal cellular Na is minimal, ranging from 0.1 to 0.2 mV.
- Estimated membrane resistance (Rm) is approximately 1 to 2 X 10(5) ohm cm2.
- The electrogenic component is directly related to the pump current.
Conclusions:
- The Na/K pump has a negligible direct electrogenic effect on the Em of human red blood cells.
- The calculated Rm suggests a relatively low membrane permeability to ions.
- These findings refine our understanding of red blood cell electrophysiology.