Down-regulation of blood-brain glucose transport in the hyperglycemic nonobese diabetic mouse.
The intracarotid injection method has been utilized to examine blood-brain barrier (BBB) glucose transport in hyperglycemic (4-6 days) mice. In anesthetized mice, Brain Uptake Indices were measured over a range of glucose concentrations from 0.010-50 mmol/l; glucose uptake was found to be saturable and kinetically characterized. The maximal velocity (Vmax) for glucose transport was 989 +/- 214 nmol.min-1.g-1. and the half-saturation constant estimated to be 5.80 +/- 1.38 mmol/l. The unsaturated Permeability Surface area product (PS) is = 171 + 8 microliters.min.-1.g-1. A rabbit polyclonal antiserum to a synthetic peptide encoding the 13 C-terminal amino acids of the human erythrocyte glucose transporter immunocytochemically confirmed the presence of the GLUT1 isoform in non-obese diabetic (NOD) mouse brain capillary endothelia. These studies indicate that a down-regulation of BBB glucose transport occurs in these spontaneously hyperglycemic mice; both BBB glucose permeability (as indicated by PS product) and transporter maximal velocity are reduced (in comparison to normoglycemic CD-1 mice), but the half-saturation constant remains unchanged.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001812:Blood-Brain Barrier; D002196:Capillaries; D002560:Cerebrovascular Circulation; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D004727:Endothelium / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism*; D051272:Glucose Transporter Type 1; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism*; D007106:Immune Sera; D007700:Kinetics; D051379:Mice; D016688:Mice, Inbred NOD; D008815:Mice, Inbred Strains; D009004:Monosaccharide Transport Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D011817:Rabbits / Q000276:immunology
D001786:Blood Glucose; D051272:Glucose Transporter Type 1; D007106:Immune Sera; D009004:Monosaccharide Transport Proteins; C495677:SLC2A1 protein, human; C495678:Slc2a1 protein, mouse; D005947:Glucose