Biomaterial Database

[Respiration and ion permeability of the inner membrane in rat "sodium" liver mitochondria]. 1997

S M Korotkov, and V V Glazunov, and E P Nikitina

Institute of Evolutionary Physiology and Biochemistry RAS, St. Petersburg.

Ion permeability of internal membrane and a respiration in isolated rat liver mitochondria, further related to as "sodium ones", were studied following replacement of K+ ions for Na+ ones in the mitochondrial matrix. As compared with the control ("potassium mitochondria"), state 4 respiration in the sodium mitochondria, energized by succinate, was shown to be enhanced in KCl or sucrose media. Oxygen consumption rates in the sodium mitochondria, being in state 3 or stimulated by 2,4-dinitrophenol, were lower than rates for the control mitochondria. This effect was much pronounced in the sucrose medium. The coefficients, characterizing the distribution of 137Cs between mitochondria and the medium, were lower for the sodium mitochondria than for the control in the presence of 2.5 mM succinate and 10(-8) M valinomycin. In comparison with the control, a more extensive swelling for the sodium mitochondria was found, first, in the medium containing 25 mM K-acetate and 100 mM sucrose for succinate-energized mitochondria, and second, in the medium containing 125 mM NH4NO3 without mitochondrial energization. Changes disclosed in respiration, swelling and coefficients of 137Cs distribution for the sodium mitochondria are supposed to be caused by non-uniform effects of Na+ and K+ ions on the water structure of mitochondrial matrix, ion permeability of internal membrane, and the activity in oxidative phosphorylation enzymes.

UI	MeSH Term	Description	Entries
D007425	Intracellular Membranes	Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.	Membranes, Intracellular,Intracellular Membrane,Membrane, Intracellular
D008930	Mitochondria, Liver	Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)	Liver Mitochondria,Liver Mitochondrion,Mitochondrion, Liver
D010085	Oxidative Phosphorylation	Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.	Phosphorylation, Oxidative,Oxidative Phosphorylations,Phosphorylations, Oxidative
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
D010539	Permeability	Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.	Permeabilities
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D002588	Cesium Radioisotopes	Unstable isotopes of cesium that decay or disintegrate emitting radiation. Cs atoms with atomic weights of 123, 125-132, and 134-145 are radioactive cesium isotopes.	Radioisotopes, Cesium
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
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D014634	Valinomycin	A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies.