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Updated: Jul 19, 2026
11:56
A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
Published on: April 11, 2014
An ascorbate-mediated transmembrane-reducing system of the human erythrocyte
The Journal of Clinical Investigation
|January 1, 1979
Summary
Human red blood cells use ascorbic acid to transfer reducing equivalents from glycolysis across the cell membrane. This process facilitates the reduction of extracellular ferricyanide to ferrocyanide.
Area of Science:
- Biochemistry
- Cell Biology
- Redox Biology
Background:
- Human erythrocytes actively metabolize glucose via glycolysis.
- Extracellular ferricyanide reduction by erythrocytes indicates a transmembrane transfer of reducing equivalents.
- The mechanism for this transmembrane electron transfer has not been fully elucidated.
Purpose of the Study:
- To investigate the role of ascorbic acid in the transmembrane reduction of ferricyanide by human erythrocytes.
- To identify the source of reducing equivalents used in this process.
Main Methods:
- Incubation of human erythrocytes with ferricyanide.
- Measurement of ferricyanide reduction.
- Analysis of ascorbic acid uptake and release.
- Investigation of the link between glycolysis and ascorbic acid reduction.
Main Results:
- Ascorbic acid facilitates the extracellular reduction of ferricyanide.
- Dehydroascorbate rapidly enters erythrocytes and is reduced intracellularly.
- Reducing equivalents appear to originate from NADH generated during glycolysis, specifically at glyceraldehyde 3-phosphate dehydrogenase.
- Reduced ascorbic acid is released from the cell to reduce ferricyanide.
Conclusions:
- Ascorbic acid acts as a shuttle for transferring reducing equivalents across the erythrocyte membrane.
- This mechanism explains how glycolysis products reduce extracellular ferricyanide.
- The erythrocyte utilizes ascorbic acid to manage redox balance and interact with extracellular redox agents.
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