Hemorheological factors of oxygen transfer in capillary tissue unit.

The supply of oxygen to tissue from capillaries may be influenced by hemorheological factors. A hemorheological model is developed for elucidating which factors play a major role in the oxygen transport to tissue. For a capillary tissue unit, a modified cylindrical model of Krogh is used. For blood, two fluids model of red blood cells (RBCs) and plasma is used where hemoglobin release effect is included. Non-equilibrium flows as well as equilibrium flows are examined for various parameters (total flow Q or RBC velocity Vr, discharge hematocrit Hd and capillary hematocrit Hc). In equilibrium flow, Hd and Q determine the oxygen transport. In non-equilibrium flow, Hc also becomes important. Especially, hemoglobin release effect becomes significant in low Hc flow, which affects the area of lethal region in tissue.