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A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
Published on: April 11, 2014
The glucose transporter-2 (GLUT2) is a low affinity dehydroascorbic acid transporter
Lorena Mardones1, Valeska Ormazabal, Ximena Romo
1Departamento de Ciencias Básicas, Universidad Católica de la Santísima Concepción, Concepción, Chile.
Biochemical and Biophysical Research Communications
|May 31, 2011
Summary
The glucose transporter GLUT2 facilitates dehydroascorbic acid uptake in rat hepatocytes and Xenopus oocytes. This study identifies GLUT2 as a low-affinity dehydroascorbic acid transporter, crucial for vitamin C metabolism.
Area of Science:
- Biochemistry
- Cell Biology
- Molecular Transport
Background:
- Dehydroascorbic acid is the oxidized form of vitamin C.
- Understanding its transport is vital for cellular redox homeostasis.
- Specific transporters for dehydroascorbic acid are not fully characterized.
Purpose of the Study:
- To investigate the molecular mechanisms of dehydroascorbic acid acquisition in different cell types.
- To identify the specific glucose transporters involved in dehydroascorbic acid transport.
- To characterize the kinetic and functional properties of these transporters.
Main Methods:
- Transport kinetics studies in rat hepatocytes, H4IIE rat hepatoma cells, and Xenopus laevis oocytes.
- Competition and inhibition assays to identify transporter specificity.
- Expression studies of GLUT2 in Xenopus oocytes.
Main Results:
- Rat hepatocytes utilize a single component, identified as GLUT2, for dehydroascorbic acid transport.
- H4IIE rat hepatoma cells express at least two dehydroascorbic acid transporters, including GLUT1 and GLUT2.
- Xenopus oocytes expressing GLUT2 confirmed its role as a low-affinity dehydroascorbic acid transporter.
Conclusions:
- GLUT2 is a key low-affinity transporter for dehydroascorbic acid in hepatocytes and hepatoma cells.
- GLUT2's role extends beyond glucose and fructose transport to include oxidized vitamin C.
- This finding provides insights into vitamin C uptake and cellular metabolism.
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