Experimental and theoretical studies of oxygen gradients in rat pial microvessels.

Using modified oxygen needle microelectrodes and intravital videomicroscopy, measurements were made of tissue oxygen tension (PO(2)) profiles near cortical arterioles and transmural PO(2) gradients in the pial arterioles of the rat. Under control conditions, the transmural PO(2) gradient averaged 1.17+/-0.

A computational model of oxygen delivery by hemoglobin-based oxygen carriers in three-dimensional microvascular networks.

A detailed computational model is developed to simulate oxygen transport from a three-dimensional (3D) microvascular network to the surrounding tissue in the presence of hemoglobin-based oxygen carriers. The model accounts for nonlinear O(2) consumption, myoglobin-facilitated diffusion and nonlinear oxyhemoglobin dissociation in the RBCs and plasma. It also includes a detailed description of intravascular resistance to O(2) transport and is capable of incorporating realistic 3D microvascular network geometries.

Modeling of oxygen diffusion from the blood vessels to intracellular organelles.

We describe recent models of oxygen transport in tissue along the pathway from the hemoglobin molecule to the mitochondria and illustrate their applications. Microvasculature is the major site of exchange between blood and parenchymal cells for gases (O2, CO2, CO, NO), nutrients, metabolic products, and drugs. These exchange processes are affected by the architecture of the microvessels and the surrounding cells; distribution of blood flow; transport characteristics of blood, cells, and interstitial space; and rates of various chemical reactions associated with the transport processes.

Calculations of oxygen transport by red blood cells and hemoglobin solutions in capillaries.

A theoretical model is developed to investigate the influence of hemoglobin-based oxygen carriers (HBOCs) on oxygen transport in capillary-size vessels. A discrete cell model is presented with red blood cells (RBCs) represented in their realistic parachute shape flowing in a single file through a capillary. The model includes the free and Hb-facilitated transport of O2 and Hb-O2 kinetics in the RBC and plasma, diffusion of free O2 in the suspending phase, capillary wall, interstitium and tissue.