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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1995-12-28
pubmed:abstractText
An in vivo model of chronic hypoglycemia was used to investigate changes in blood-brain barrier (BBB) glucose transport activity and changes in the expression of GLUT1 mRNA and protein in brain microvasculature occurring as an adaptive response to low circulating glucose levels. Chronic hypoglycemia was induced in rats by constant infusion of insulin via osmotic minipumps; control animals received infusions of saline. The criterion for chronic hypoglycemia was an average blood glucose concentration of < 2.3 mmol/l (42 mg/dl) after 5 days. The average blood glucose concentration at the end of the experimental period in the rats selected for study was 2.0 +/- 0.1 mmol/l (36 +/- 1 mg/dl) vs. 4.9 +/- 0.1 mmol/l (88 +/- 1 mg/dl) in the controls. Internal carotid artery perfusion studies demonstrated an increase in the BBB permeability-surface area (PS) product of 40% (P < 0.0005) in the chronically hypoglycemic animals as compared with controls. Western blotting of solubilized isolated brain capillaries demonstrated a 51% increase (P < 0.05) in immunoreactive BBB GLUT1 in the chronically hypoglycemic rats, and Northern blotting of whole-brain poly(A+) mRNA revealed a 50% increase in the GLUT1-to-actin ratio in the insulin-treated group (P < 0.05). Northern blotting analysis of microvessel-depleted total brain poly(A+) showed that the increase in GLUT1 mRNA in the chronically hypoglycemic rats was restricted to the BBB. The present study demonstrates increased expression of GLUT1 mRNA and protein at the BBB in chronic hypoglycemia and suggests that this increase is responsible for the compensatory increase in BBB glucose transport activity that occurs with chronically low circulating blood glucose levels.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1399-404
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Upregulation of blood-brain barrier GLUT1 glucose transporter protein and mRNA in experimental chronic hypoglycemia.
pubmed:affiliation
Department of Medicine, University of California at Los Angeles 90095-1682, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't