Glucose inhibits cellular ascorbic acid uptake by fibroblasts in vitro

Area of Science:

• Biochemistry
• Cell Biology
• Diabetology

Background:

• Local ascorbic acid deficiency in tissues is linked to diabetic angiopathies.
• Hyperglycemia is a significant contributor to local ascorbic acid deficiency.

Purpose of the Study:

• To investigate the effect of glucose on the uptake of L-[1-14C] ascorbic acid by fibroblasts in vitro.
• To determine if glucose concentration impacts ascorbic acid uptake.

Main Methods:

• In vitro study using fibroblasts.
• Measuring the uptake of radiolabeled L-ascorbic acid (L-[1-14C] ascorbic acid).
• Assessing the effect of varying glucose concentrations on uptake rates.

Main Results:

• Glucose significantly inhibited ascorbic acid uptake by fibroblasts.
• The inhibition was concentration-dependent, occurring instantly upon glucose addition.
• Observed uptake rates suggest a potential benefit from supplemental ascorbic acid.

Conclusions:

• Hyperglycemia directly impairs cellular ascorbic acid uptake, leading to local deficiency.
• This mechanism supports the link between hyperglycemia and tissue ascorbic acid depletion.
• Supplemental ascorbic acid may be beneficial for individuals with hyperglycemia to maintain adequate tissue levels.