title: The vascular wall as a regulator of tissue oxygenation.
abstract: OBJECTIVE
  The development of the phosphorescence quenching oxygen measurement technique has allowed for a simultaneous measurement of intra and perivascular partial pressure oxygen along arteriolar vessels in vivo. Mapping the microvascular distribution and oxygen gradients across the vascular walls using this high-resolution technique reveals the existence of large radial gradients between the vasculature and the tissue, with concomitant longitudinal oxygen loss. Mass balance analysis along vessel segments indicates that the vascular wall has a high rate of oxygen consumption. This review presents the current status of in-vivo studies on the partitioning of oxygen between blood, the vascular wall and the surrounding tissue, thereby positioning an oxygen sink between blood and tissue regulating oxygen release.
  
  
  RESULTS
  Induced vasoactivity (vasoconstriction and vasodilation) has been shown to modulate oxygen consumption of the vascular wall and directly affect the portion of oxygen available to the tissue. Inhibition of the endothelial layer of the vessel wall resulted in a decrease in the oxygen gradient across the vessel.
  
  
  CONCLUSIONS
  The vascular wall is a sink for oxygen. The modulation of vessel wall oxygen consumption can substantially impact the amount of oxygen released to the tissue.
authors.affiliation: Department of Bioengineering 0412, University of California-San Diego, La Jolla, CA 92093, USA. agtsai@ucsd.edu
authors.forename: Amy G
authors.initials: AG
authors.lastname: Tsai
authors.forename: Barbara
authors.initials: B
authors.lastname: Friesenecker
authors.forename: Pedro
authors.initials: P
authors.lastname: Cabrales
authors.forename: Nanae
authors.initials: N
authors.lastname: Hangai-Hoger
authors.forename: Marcos
authors.initials: M
authors.lastname: Intaglietta
mesh_terms: D001158:Arteries / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology*; D006801:Humans; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D010313:Partial Pressure; D014661:Vasoconstriction; D014664:Vasodilation
chemical_list: D010100:Oxygen