Microvascular blood flow resistance

Role of endothelial surface layer

Axel R. Pries, Timothy W Secomb, Helfried Jacobs, Markus Sperandio, Kurt Osterloh, Peter Gaehtgens

Research output: Contribution to journalArticle

137 Citations (Scopus)

Abstract

Observations of blood flow in microvas-cular networks have shown that the resistance to blood flow is about twice that expected from studies using narrow glass tubes. The goal of the present study was to test the hypothesis that a macromolecular layer (glycocalyx) lining the endothelial surface contributes to blood flow resistance. Changes in flow resistance in microvascular networks of the rat mesentery were observed with microinfusion of enzymes targeted at oligosaccharide side chains in the glycocalyx. Infusion of heparinase resulted in a sustained decrease in estimated flow resistance of 14-21%, hydrodynamically equivalent to a uniform increase of vessel diameter by 1μ.m. Infusion of neuraminidase led to accumulation of platelets on the endothelium and doubled flow resistance. Additional experiments in untreated vascular networks in which microvascular blood flow was reduced by partial microocclusion of the feeding arteriole showed a substantial increase of flow resistance at low flow rates (average capillary flow velocities < 100 diameters/s). These observations indicate that the glycocalyx has significant hemodynamic relevance that may increase at low flow rates, possibly because of a shear-dependent variation in glycocalyx thickness.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume42
Issue number5
StatePublished - 1997

Fingerprint

Glycocalyx
Heparin Lyase
Mesentery
Neuraminidase
Arterioles
Microvessels
Oligosaccharides
Endothelium
Glass
Blood Vessels
Blood Platelets
Hemodynamics
Enzymes

Keywords

  • Glycocalyx
  • Microvascular networks
  • Rheology
  • Shear rate

ASJC Scopus subject areas

  • Physiology

Cite this

Microvascular blood flow resistance : Role of endothelial surface layer. / Pries, Axel R.; Secomb, Timothy W; Jacobs, Helfried; Sperandio, Markus; Osterloh, Kurt; Gaehtgens, Peter.

In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 42, No. 5, 1997.

Research output: Contribution to journalArticle

Pries, Axel R. ; Secomb, Timothy W ; Jacobs, Helfried ; Sperandio, Markus ; Osterloh, Kurt ; Gaehtgens, Peter. / Microvascular blood flow resistance : Role of endothelial surface layer. In: American Journal of Physiology - Heart and Circulatory Physiology. 1997 ; Vol. 42, No. 5.
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