1987 Fiscal Year Final Research Report Summary
Red Cell Rheology in Pulsative Flow
| Project/Area Number |
61480100
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General physiology
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| Research Institution | Ehime University |
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Principal Investigator |
SHIGA Takeshi Ehime University, Professor, 医学部, 教授 (10028350)
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| Co-Investigator(Kenkyū-buntansha) |
KON Kazunori Ehime University, Lecturer, 医学部, 講師 (40093926)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Pulsative Flow / Erythrocytes / Deformation / Blood Flow / 圧力汲伝播 |
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| Research Abstract |
The flow properties of red cells affect the rheological characteristics of circulating blood. However, a little is known about red cell behavior under the pulsative shear flow which is physiological circumstance in arteries. Therefore, we studied the red cell rheology in pulsative flow with a rheoscope and a pulsative flow system built in our laboratory.
(1) To reveal the response of red cell deformation to a rapid change in shear stress, the time-dependent process of red cell deformation in a diluted suspension was observed with a rheoscope. Shear stress was modulated sinusoidally. At a modulation frequency of above 2Hz, the retarded response was detected in the up-phase of the sinusoidally modulated shear stress. The response was affected by (i) intracellular viscosity, (ii) membrane stiffness, and (iii) intracellular calcium content.
(2) The effect of hematocrit on red cell deformation in pulsative shear flow was studied with the pulsative shear flow system controlled by a computer. (i) The enhancement of deformation was detected with increasing hematocrit. (ii) The time dependent red cell deformation showed that shape recovery to biconcave shape in the down phase of pulsative shear stress was retarded at high hematocrit.
(3) The effect of red cell deformation on the pressure-flow relationship of pulsative flow was studied with the pulsative flow system equipped with a rigid tube of 250 um in diameter. Lateral pressure was measured at two points along the tube with pressure transducers to measure the efficiency of pressure transmission between the two points. It was revealed that suspension viscosity, but not red cell deformability, affected the efficiency of the pressure transmission.
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