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Updated: Jul 26, 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
Ascorbic acid transport by isolated bovine adrenal cortical cells
Endocrinology
|March 1, 1980
Summary
Bovine adrenal cells accumulate ascorbic acid via a carrier-mediated process sensitive to ACTH. However, ACTH does not deplete intracellular ascorbic acid, suggesting compartmentalization within the cells.
Area of Science:
- Biochemistry
- Cell Biology
- Endocrinology
Background:
- Adrenal cortical cells are known to be sensitive to ACTH.
- Ascorbic acid (vitamin C) plays crucial roles in cellular functions.
Purpose of the Study:
- To investigate the mechanism of ascorbic acid transport in bovine adrenal cortical cells.
- To determine the effect of ACTH on intracellular ascorbic acid levels and transport.
Main Methods:
- Incubation of viable, ACTH-sensitive bovine adrenal cortical cells with [1-14C]ascorbic acid.
- Analysis of ascorbic acid transport kinetics, calcium dependency, and ACTH inhibition.
- Measurement of intracellular ascorbic acid concentrations using chemical methods and radioactive labeling.
- Investigation of ascorbic acid depletion in isolated rat adrenal glands post-adrenalectomy.
Main Results:
- Bovine adrenal cells actively accumulate ascorbic acid via a saturable, Ca2+-dependent, carrier-mediated transport system.
- ACTH maximally inhibits ascorbic acid transport at concentrations that maximally stimulate steroidogenesis.
- Despite significant accumulation of labeled ascorbic acid, intracellular concentrations measured chemically remain unchanged, suggesting compartmentalization.
- ACTH does not deplete ascorbic acid from labeled cells, and adrenalectomy leads to a rapid loss of a significant portion of adrenal ascorbate.
Conclusions:
- Bovine adrenal cells possess a specific transport system for ascorbic acid, modulated by ACTH.
- Ascorbic acid likely exists in at least two intracellular pools, with only one pool being ACTH-depletable and potentially lost upon cell isolation or adrenalectomy.
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