Biomaterial Database

Modulation of the mitochondrial permeability transition by nitric oxide. 1997

Balakirev MYu, and V V Khramtsov, and G Zimmer

Institute of Chemical Kinetics & Combustion, Novosibirsk, Russia.

The influence of nitric oxide on mitochondrial permeability transition (MPT) phenomenon was studied. NO was generated by photolysis of S-nitroso-N-acetylcysteine, AcCys(NO), with green light (lambda = 550 nm). Two distinct effects of nitric oxide on rat liver mitochondria were identified. First, NO accelerated an onset of swelling in Ca2(+)-loaded mitochondria in a cyclosporin-A-sensitive manner acting as an inducer of permeability transition. This was, apparently, a result of irreversible alteration of mitochondrial function accompanying the inhibition of respiratory chain in the presence of calcium. Formation of ESR-visible iron-sulfur dinitrosyl complexes (g = 2.041) could also contribute to the irreversible changes resulting in MPT induction. Second, NO changed significantly the response of mitochondria to Ca2+/phosphate-induced MPT, acting as a regulator of permeability transition. In this case the action of nitric oxide led to division of the mitochondria into two subpopulations: one which underwent the rapid permeability transition and another in which the MPT was inhibited. The effect of NO on Ca2+/Pi-induced MPT was transient and resulted from reversible inhibition of cytochrome oxidase followed by the changes in transmembrane potential and Ca2+ distribution. The characteristic time of duration of these NO modulated effects depended on nitric oxide as well as on oxygen concentrations. With increasing NO at fixed oxygen concentrations, this time levelled off to reach a maximum value which was inversely related to the oxygen concentration. It is concluded that under physiological condition the duration of reversible NO effects on mitochondrial function could be determined by oxygen concentration.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D009569	Nitric Oxide	A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.	Endogenous Nitrate Vasodilator,Mononitrogen Monoxide,Nitric Oxide, Endothelium-Derived,Nitrogen Monoxide,Endothelium-Derived Nitric Oxide,Monoxide, Mononitrogen,Monoxide, Nitrogen,Nitrate Vasodilator, Endogenous,Nitric Oxide, Endothelium Derived,Oxide, Nitric,Vasodilator, Endogenous Nitrate
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
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D010782	Photolysis	Chemical bond cleavage reactions resulting from absorption of radiant energy.	Photodegradation
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004578	Electron Spin Resonance Spectroscopy	A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.	ENDOR,Electron Nuclear Double Resonance,Electron Paramagnetic Resonance,Paramagnetic Resonance,Electron Spin Resonance,Paramagnetic Resonance, Electron,Resonance, Electron Paramagnetic,Resonance, Electron Spin,Resonance, Paramagnetic
D000111	Acetylcysteine	The N-acetyl derivative of CYSTEINE. It is used as a mucolytic agent to reduce the viscosity of mucous secretions. It has also been shown to have antiviral effects in patients with HIV due to inhibition of viral stimulation by reactive oxygen intermediates.	Mercapturic Acid,Acemuc,Acetabs,Acetylcystein AL,Acetylcystein Atid,Acetylcystein Heumann,Acetylcystein Trom,Acetylcysteine Hydrochloride,Acetylcysteine Sodium,Acetylcysteine Zinc,Acetylcysteine, (D)-Isomer,Acetylcysteine, (DL)-Isomer,Acetylcysteine, Monoammonium Salt,Acetylcysteine, Monosodium Salt,Acetylin,Acetyst,Acétylcystéine GNR,Airbron,Alveolex,Azubronchin,Bisolvon NAC,Bromuc,Broncho-Fips,Broncholysin,Broncoclar,Codotussyl,Cystamucil,Dampo Mucopect,Eurespiran,Exomuc,Fabrol,Fluimucil,Fluprowit,Frekatuss,Genac,Hoestil,Ilube,Jenacystein,Jenapharm,Lantamed,Larylin NAC,Lindocetyl,M-Pectil,Muciteran,Muco Sanigen,Mucomyst,Mucosil,Mucosol,Mucosolvin,N-Acetyl-L-cysteine,N-Acetylcysteine,NAC AL,NAC Zambon,Optipect Hustengetränk,Siccoral,Siran,Solmucol,acebraus,durabronchal,mentopin Acetylcystein,Acetylcystein, mentopin,Acid, Mercapturic,Broncho Fips,BronchoFips,Hustengetränk, Optipect,Hydrochloride, Acetylcysteine,M Pectil,MPectil,Monoammonium Salt Acetylcysteine,Monosodium Salt Acetylcysteine,Mucopect, Dampo,N Acetyl L cysteine,N Acetylcysteine,NAC, Bisolvon,Sanigen, Muco,Sodium, Acetylcysteine,Zambon, NAC,Zinc, Acetylcysteine