Biomaterial Database

Comparative facilitated transport of oxygen. 1986

J M Gonzalez-Fernandez, and S E Atta

Numerical solutions were obtained for a model of facilitated transport of O2. The dependence of the facilitated flow on the concentrations of O2 at the two boundaries of the transport path was studied. The numerical values of the parameters correspond to the adult Ascaris lumbricoides and to vertebrate red striated muscle. A global control principle is formulated. This states that for every fixed O2 concentration at the low concentration boundary there exists an O2 concentration at the high concentration boundary for which the facilitated flow is maximum. The collection of these maxima makes possible the existence of a global adjustment of the facilitated transport in contradistinction to the mere presence of a local maximum. The ranges of the pairs of boundary O2 concentrations thus defined and for which the facilitated flow is within 70% of its attainable maximum were found to coincide with the physiological ranges of boundary O2 concentrations for the Ascaris and vertebrate striated muscle. This phenomenon has the character of a graded compensatory mechanism to hypoxia. It is an intrinsic property of the carrier transport system and does not depend on sensors for hypoxia.

UI	MeSH Term	Description	Entries
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009211	Myoglobin	A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.
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
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
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
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
D001200	Ascaris	A genus of nematodes of the superfamily ASCARIDOIDEA whose species usually inhabit the intestine.	Ascari
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill