Related Experiment Videos
High ascorbic acid content in the rat endocrine pancreas.
Diabetologia
|November 1, 1991
Summary
Ascorbic acid (vitamin C) is crucial for peptide amidations in the pancreas. Neonatal rats show high pancreatic ascorbic acid levels, which decline with age, highlighting its developmental importance.
Area of Science:
- Endocrinology
- Biochemistry
- Cell Biology
Background:
- Peptidyl alpha-amidation is vital for biologically active peptides, particularly in the endocrine pancreas.
- Ascorbic acid is a known co-factor essential for this post-translational modification.
Purpose of the Study:
- To quantify ascorbic acid levels in the rat endocrine pancreas during development.
- To investigate the role of ascorbic acid in pancreatic islet cells and secretory granules.
Main Methods:
- High-performance liquid chromatography (HPLC) was used for sensitive measurement of ascorbic acid.
- Ascorbic acid concentrations were analyzed in whole pancreas, isolated islet cells, and secretory granules.
- In vitro culture experiments assessed ascorbic acid uptake and retention in islets and cells.
Main Results:
- Neonatal rats exhibited high pancreatic ascorbic acid concentrations, peaking at 2 days old (42.5 nmol/mg protein), then decreasing with age.
- Isolated islet cells and secretory granules showed significant intracellular ascorbic acid concentrations.
- Ascorbic acid levels decreased in cultured islets/cells without supplementation, with granules showing slower depletion.
- Glucose concentration influenced ascorbic acid uptake in cultured islets.
Conclusions:
- Ascorbic acid plays a significant role in the developing rat endocrine pancreas.
- Pancreatic islet cells and their secretory granules actively accumulate and retain ascorbic acid.
- Ascorbic acid levels are sensitive to both age and culture conditions, influenced by glucose.