Biomaterial Database

Prediction of microcirculatory oxygen transport by erythrocyte/hemoglobin solution mixtures. 1998

T C Page, and W R Light, and J D Hellums

Biopure Corporation, 11 Hurley Street, Cambridge, Massachusetts 02141, USA.

A mathematical model has been developed to predict oxygen transport by erythrocyte/acellular hemoglobin solution mixtures flowing in arteriolar-sized vessels (20 to 100 micron diameter). The model includes erythrocyte and extracellular hemoglobin solution phases, radial hematocrit and velocity gradients, axial convection, and radial diffusion of both oxygen and oxyhemoglobin. Model simulations were compared with experimental data from an in vitro capillary model where all of the geometric, physical, and transport parameters are known accurately. A new approach to shear augmentation of transport in 25-micron-diameter conduits was developed. Comparison of theory with experiment suggests that shear augmentation in this flow regime is primarily an extracellular phenomenon produced by cell-cell interactions. Negligible shear augmentation was seen in erythrocyte suspensions in plasma due to the relatively low solubility of oxygen in the plasma phase. Good agreement was found between the theoretical simulations and experimental data for release experiments even neglecting shear augmentation. However, treatment of shear augmentation significantly improved agreement between theoretical simulations and experimental data for oxygen uptake. The model was used to determine the effects on oxygen transport of varying extracellular hemoglobin concentration and extracellular hemoglobin oxygen binding characteristics. It is known that hemoglobin solutions transport oxygen more efficiently than erythrocyte suspensions of the same overall hemoglobin content. Model simulations show that erythrocyte/hemoglobin solution mixtures with 30% extracellular hemoglobin transport oxygen with virtually the same efficiency as pure hemoglobin solutions of the same overall hemoglobin content. Additional simulations predict that erythrocyte/hemoglobin solution mixtures transport oxygen more efficiently than Rbc suspensions, even if the extracellular hemoglobin has a high oxygen affinity.

UI	MeSH Term	Description	Entries
D008833	Microcirculation	The circulation of the BLOOD through the MICROVASCULAR NETWORK.	Microvascular Blood Flow,Microvascular Circulation,Blood Flow, Microvascular,Circulation, Microvascular,Flow, Microvascular Blood,Microvascular Blood Flows,Microvascular Circulations
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D008962	Models, Theoretical	Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Experimental Model,Experimental Models,Mathematical Model,Model, Experimental,Models (Theoretical),Models, Experimental,Models, Theoretic,Theoretical Study,Mathematical Models,Model (Theoretical),Model, Mathematical,Model, Theoretical,Models, Mathematical,Studies, Theoretical,Study, Theoretical,Theoretical Model,Theoretical Models,Theoretical Studies
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D011237	Predictive Value of Tests	In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.	Negative Predictive Value,Positive Predictive Value,Predictive Value Of Test,Predictive Values Of Tests,Negative Predictive Values,Positive Predictive Values,Predictive Value, Negative,Predictive Value, Positive
D004912	Erythrocytes	Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.	Blood Cells, Red,Blood Corpuscles, Red,Red Blood Cells,Red Blood Corpuscles,Blood Cell, Red,Blood Corpuscle, Red,Erythrocyte,Red Blood Cell,Red Blood Corpuscle
D006454	Hemoglobins	The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.	Eryhem,Ferrous Hemoglobin,Hemoglobin,Hemoglobin, Ferrous
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic