Functional variations in parenchymal microvascular systems within the brain.
Variations in microvascular system functions were observed among a number of brain areas. The rates of local blood flow varied 18-fold among areas and were extremely high in neuroendocrine structures. Marked differences in blood flow were also found within some brain structures. The volume of radiolabeled blood in perfused parenchymal microvessels ranged from 5 to 70 microliters/g and correlated closely with local cerebral blood flow. The hematocrits within parenchymal microvessels were 45-75% of the arterial hematocrit, which indicates that red cells more rapidly traverse brain microvessels than do plasma proteins. The mean transit times of blood through parenchymal microvessels were extremely short and ranged from 0.3 to 0.6 s.
Fenstermacher
J
J
Department of Neurological Surgery, State University of New York, Stony Brook 11794-8122.
Nakata
H
H
Tajima
A
A
Lin
S Z
SZ
Otsuka
T
T
Acuff
V
V
Wei
L
L
Bereczki
D
D
D000818:Animals; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply* / Q000378:metabolism; D002196:Capillaries / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006400:Hematocrit; D008297:Male; D008833:Microcirculation / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012709:Serum Albumin / Q000378:metabolism; D014018:Tissue Distribution
D012709:Serum Albumin