Aggregate formation of erythrocytes in postcapillary venules

Sangho Kim, Aleksander S. Popel, Marcos Intaglietta, Paul C. Johnson

Research output: Contribution to journalArticlepeer-review

64 Scopus citations


The purpose of the present study was to obtain information on erythrocyte aggregate formation in vivo. The movements of erythrocytes in postcapillary venules of the rat spinotrapezius muscle at various flow rates were recorded with a high-speed video camera before and after infusion of dextran 500. To distinguish aggregates, the following criteria were used: 1) a fixed distance (4 μm) between the center points of two adjacent cells, 2) lack of visible separation between the adjacent cells, and 3) movement of the adjacent cells in the same direction. Without dextran 500 infusion, 11 and 5% of erythrocytes formed aggregates in low (33.2 ± 28.3 s) and high pseudoshear (144.2 ± 58.3 s) conditions, respectively, based on the above criteria. After dextran 500 infusion, 53% of erythrocytes satisfied the criteria in the low pseudoshear condition (26.5 ± 17.0 s) and 13% of erythrocytes met the criteria in the high pseudoshear condition (240.0 ± 85.9 s), indicating erythrocyte aggregation is strongly associated with shear rate. Approximately 90% of aggregate formation occurred in a short time period (0.15-0.30 s after entering the venule) in a region 15 to 30 μm from the entrance. The time delay may reflect rheological entrance conditions in the venule.

Original languageEnglish (US)
Pages (from-to)H584-H590
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Issue number2 57-2
StatePublished - Feb 2005


  • Hemodynamics
  • In vivo blood rheology
  • In vivo microscopy

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


Dive into the research topics of 'Aggregate formation of erythrocytes in postcapillary venules'. Together they form a unique fingerprint.

Cite this