Blood flow and red blood cell deformation in nonuniform capillaries: effects of the endothelial surface layer.
Microcirculation
; 9(3): 189-96, 2002 Jul.
Article
en En
| MEDLINE
| ID: mdl-12080416
OBJECTIVE: A theoretical model is used to examine the mechanics of red blood cell (RBC) motion in nonuniform capillaries. The model includes effects of the endothelial surface layer (ESL), which is a layer of macromolecules adjacent to the endothelium and which impedes plasma flow. METHODS: The motion of an RBC traversing a capillary with diameter varying sinusoidally between 5.4 microm and 7.4 microm is simulated numerically. The ESL is assumed to be 0.7-microm wide and deformable. Axisymmetric RBC shapes are assumed. Lubrication theory is used to analyze the motion of plasma around the RBC and through the ESL. RESULTS: In a nonuniform capillary with no ESL, moving RBCs undergo large transient deformations and predicted flow resistance is substantially higher than in a uniform capillary with the same mean diameter. The presence of a deformable ESL reduces the transient fluid shear stresses and deformations experienced by RBCs traversing a nonuniform capillary. With an ESL, the increase in flow resistance resulting from nonuniformity is less than twofold versus three- to fourfold with no ESL in vessel geometries with the same ESL-free luminal region. CONCLUSIONS: The presence of the ESL reduces the impact of capillary irregularity on flow resistance and may protect RBCs traversing irregular capillaries from damage due to large, rapidly fluctuating external stresses.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Capilares
/
Endotelio Vascular
/
Deformación Eritrocítica
/
Modelos Cardiovasculares
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Microcirculation
Asunto de la revista:
ANGIOLOGIA
Año:
2002
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos