Cell-free plasma layer in cerebral microvessels.
Two diameters of vessel and red cell column in cerebral microvessels (> 29.8 microns in diameter) of cat were measured together with red cell velocity, using a two fluorescent tracer method. A fluorescein isothiocyanate (FITC)-labeled red cell was adopted as a flow tracer to measure the cell velocity with a dual window technique. Based on the fluorescence image, the red cell column diameter was measured. Plasma was stained with rhodamine-B isothiocyanate (RITC)-labeled dextran to measure the vessel diameter. The thickness of the cell-free plasma layer could be determined from the difference of the two diameters. The obtained thickness of the cell-free layer was not described by a simple function of vessel diameter or red cell velocity; it was dependent on the pseudo shear rate defined by the ratio of cell velocity to vessel radius. The layer thickness increased with a decrease in the pseudo shear rate.
Yamaguchi
S
S
Department of Microcirculatory Science, National Cardiovascular Center Research Institute, Osaka, Japan.
Yamakawa
T
T
Niimi
H
H
D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D002415:Cats; D002560:Cerebrovascular Circulation; D004912:Erythrocytes / Q000502:physiology; D008833:Microcirculation / Q000033:anatomy & histology; D008856:Microscopy, Fluorescence; D010949:Plasma