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Published on: November 16, 2011
Blood-brain glucose transfer: repression in chronic hyperglycemia
Science (New York, N.Y.)
|October 23, 1981
Summary
Rapidly lowering blood glucose in diabetic patients can cause brain hypoglycemia symptoms due to impaired glucose transport. Chronic hyperglycemia in rats reduced blood-brain barrier glucose transport capacity, leading to lower brain glucose uptake.
Area of Science:
- Neuroscience
- Endocrinology
- Metabolic Research
Background:
- Diabetic patients with hyperglycemia may experience cerebral hypoglycemia symptoms when blood glucose is normalized.
- These symptoms suggest impaired glucose transport from blood to the brain.
Purpose of the Study:
- To investigate the effect of chronic hyperglycemia on glucose transport across the blood-brain barrier.
- To determine if hyperglycemia induces adaptive changes in brain glucose transport mechanisms.
Main Methods:
- Utilized a rat model with experimentally induced chronic hyperglycemia.
- Measured maximal glucose transport capacity of the blood-brain barrier before and after glucose normalization.
- Assessed glucose transport rate into the brain.
Main Results:
- Chronic hyperglycemia reduced the maximal glucose transport capacity of the blood-brain barrier from 400 to 290 micromoles per 100 grams per minute in rats.
- Lowering plasma glucose to normal levels resulted in a 20% decrease in the glucose transport rate into the brain.
- These findings indicate a functional impairment of the glucose transport system.
Conclusions:
- Chronic hyperglycemia leads to adaptive, repressive changes in the glucose transport mechanism within brain endothelial cells.
- Reduced glucose transport capacity contributes to cerebral symptoms of hypoglycemia in diabetic patients with rapidly normalized glucose levels.
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