Vascular perfusion and blood-brain glucose transport in acute and chronic hyperglycemia.
We studied the effects of acute and streptozotocin-induced chronic hyperglycemia on regional brain blood flow and perfusion characteristics, and on the regional transport of glucose across the blood-brain barrier in awake rats. We found (1) a generalized decrease in regional brain blood flow in both acute and chronic hyperglycemia; (2) that chronic, but not acute, hyperglycemia is associated with a marked and diffuse decrease in brain L-glucose space; and (3) that chronic hyperglycemia does not alter blood-to-brain glucose transport. Taken together, these results suggest that in streptozotocin-induced chronic hyperglycemia, there is a reduction in the proportion of perfused brain capillaries and/or an alteration in brain endothelial membrane properties resulting in decreased noncarrier diffusion of glucose.
Harik
S I
SI
Department of Neurology, University Hospitals of Cleveland, OH 44106.
LaManna
J C
JC
D000818:Animals; D001692:Biological Transport; D001812:Blood-Brain Barrier; D002196:Capillaries / Q000503:physiopathology; D002531:Cerebellum / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology; D005947:Glucose / Q000378:metabolism*; D006624:Hippocampus / Q000503:physiopathology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D005947:Glucose