Blood-brain glucose transfer in the mouse.
The intracarotid injection method has been utilized to examine blood-brain barrier (BBB) glucose transport in normal mice, and after a 2-day fast. In anesthetized mice, cerebral blood flow (CBF) rates were reduced from 0.86 ml.min-1 x gm-1 in control to 0.80 ml.min-1 x gm-1 in fasted animals (p > 0.05). Brain Uptake Indices were significantly (p < 0.05) higher in fasted (plasma glucose = 4.7 mM) than control (plasma glucose = 6.5 mM) mice, while plasma glucose was significantly lower. The maximal velocity (Vmax) for glucose transport was 1562 +/- 303 nmoles.min-1 x g-1, and the half-saturation constant (Km =) 6.67 +/- 1.46 mM in normally fed mice. In fasted mice the Vmax was 2053 +/- 393 nmoles.min-1 x g-1 (p > 0.05), and the half-saturation constant (Km =) 7.40 +/- 1.60 mM (not significant, P > 0.05). A rabbit polyclonal antiserum to a synthetic peptide encoding the 13 C-terminal amino acids of the human erythrocyte glucose transporter (GLUT-1) immunocytochemically confirmed that the mouse brain capillary endothelial glucose transporter is a GLUT-1 transporter, and immunoreactivity was similar in brain endothelia from fed and fasted animals. In conclusion, after a 2-day fast in the mouse, we saw significant reductions in forebrain weight (7%), and plasma glucose levels (27%). Increased brain glucose extraction (25%, p < 0.05), and a 22% increase in the unsaturated permeability-surface area product (p < 0.05) was also observed.
Cornford
E M
EM
Southwestern Regional V.A. Epilepsy Center, Veterans Administration West Los Angeles Medical Center, CA 90073.
Young
D
D
Paxton
J W
JW
Hyman
S
S
Farrell
C L
CL
Elliott
R B
RB
D000818:Animals; D001692:Biological Transport; D001783:Blood Flow Velocity; D001786:Blood Glucose / Q000378:metabolism*; D001812:Blood-Brain Barrier; D001835:Body Weight; D001921:Brain / Q000098:blood supply; D002196:Capillaries / Q000378:metabolism; D002560:Cerebrovascular Circulation; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D051272:Glucose Transporter Type 1; D007700:Kinetics; D008297:Male; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000032:analysis / Q000378:metabolism
D001786:Blood Glucose; D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495678:Slc2a1 protein, mouse