Biomaterial Database

Kinetics of O2 uptake and release by red cells in stopped-flow apparatus: effects of unstirred layer. 1985

R A Holland, and H Shibata, and P Scheid, and J Piiper

Using a stopped-flow apparatus, measurements were made of the velocity of uptake and release of oxygen by red cells of man, sheep and goat, three species of widely differing red cell size. The results were used to calculate resistances to O2 uptake provided by: (1) any unstirred layer (USL) outside the cells; (2) the cell membrane; and (3) the cell substance, in which the process of simultaneous diffusion and chemical reaction occurs. For O2 release, the USL was virtually abolished by using sufficient dithionite in the reactant buffer for it to diffuse up to the cell membrane and mop up O2 as it passes out of the cell. Hence, differences in the rate of O2 uptake and release allowed estimation of the resistance and thickness of the USL. Its thickness in the three species was between 0.7 and 0.9 micron; it provided at least 70% of the resistance to O2 uptake located outside the cell interior (cell membrane plus USL). Existence of the USL slows the uptake of O2 in the stopped-flow apparatus by a factor of at least 1.8 to 2.0.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
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
D010827	Physiology	The biological science concerned with the life-supporting properties, functions, and processes of living organisms or their parts.
D002021	Buffers	A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.	Buffer
D004058	Diffusion	The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.	Diffusions
D004163	Diphosphoglyceric Acids	Glyceric acids where two of the hydroxyl groups have been replaced by phosphates.	Bisphosphoglycerates,Acids, Diphosphoglyceric
D004910	Erythrocyte Membrane	The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.	Erythrocyte Ghost,Red Cell Cytoskeleton,Red Cell Ghost,Erythrocyte Cytoskeleton,Cytoskeleton, Erythrocyte,Cytoskeleton, Red Cell,Erythrocyte Cytoskeletons,Erythrocyte Ghosts,Erythrocyte Membranes,Ghost, Erythrocyte,Ghost, Red Cell,Membrane, Erythrocyte,Red Cell Cytoskeletons,Red Cell Ghosts
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
D005260	Female		Females