scholarly journals Free-radical-mediated fragmentation of monoamine oxidase in the mitochondrial membrane Roles for lipid radicals

1986 ◽  
Vol 240 (2) ◽  
pp. 489-494 ◽  
Author(s):  
R T Dean ◽  
S M Thomas ◽  
A Garner
Keyword(s):  
Lipid Peroxidation ◽  
Monoamine Oxidase ◽  
Gamma Irradiation ◽  
Hydroxyl Radicals ◽  
Protein Turnover ◽  
Mitochondrial Membrane ◽  
Cross Linking ◽  
Submitochondrial Particles ◽  
Protein Activity ◽  
Lipid Radicals

A flux of hydroxyl radicals generated by gamma-irradiation can fragment monoamine oxidase in the membrane of submitochondrial particles. This fragmentation can be inhibited by mannitol and in addition is more extensive in monoamine oxidase preparations that have been depleted of lipid. This latter observation is consistent with the higher yields of fragmentation induced by hydroxyl radicals in soluble proteins in the absence of added lipids. In the absence of oxygen, gamma-irradiation of submitochondrial particles leads to cross-linking reactions. A flux of hydroperoxyl radicals also causes fragmentation, whereas one of superoxide is virtually inactive in this respect. The irradiation of submitochondrial particles leads in addition to the accumulation of products of lipid peroxidation. When these irradiated preparations are exposed to ferrous or cupric salts a further fragmentation of monoamine oxidase ensues, especially at acid pH. These transition-metal-catalysed reactions do not occur with irradiated preparations depleted of lipid, and the post-irradiation protein modifications are concomitant with further lipid peroxidation. The data indicate roles for lipid radicals in both fragmentation and cross-linking reactions of proteins in biological membranes. These reactions may have an important bearing on control of protein activity and of protein turnover in membranes.

scholarly journals Graphene Oxide and Reduced Graphene Oxide Exhibit Cardiotoxicity Through the Regulation of Lipid Peroxidation, Oxidative Stress, and Mitochondrial Dysfunction

2021 ◽  
Vol 9 ◽  
Author(s):  
Jian Zhang ◽  
Hong-Yan Cao ◽  
Ji-Qun Wang ◽  
Guo-Dong Wu ◽  
Lin Wang
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Graphene Oxide ◽  
Membrane Potential ◽  
Gamma Irradiation ◽  
Cell Apoptosis ◽  
Mitochondrial Membrane ◽  
H9c2 Cells

ObjectiveGraphene has been widely used for various biological and biomedical applications due to its unique physiochemical properties. This study aimed to evaluate the cardiotoxicity of graphene oxide (GO) and reduced GO (rGO) in vitro and in vivo, as well as to investigate the underlying toxicity mechanisms.MethodsGO was reduced by gamma irradiation to prepare rGO and then characterized by UV/visible light absorption spectroscopy. Rat myocardial cells (H9C2) were exposed to GO or rGO with different absorbed radiation doses. The in vitro cytotoxicity was evaluated by MTT assay, cell apoptosis assay, and lactate dehydrogenase (LDH) activity assay. The effects of GO and rGO on oxidative damage and mitochondrial membrane potential were also explored in H9C2 cells. For in vivo experiments, mice were injected with GO or rGO. The histopathological changes of heart tissues, as well as myocardial enzyme activity and lipid peroxidation indicators in heart tissues were further investigated.ResultsrGO was developed from GO following different doses of gamma irradiation. In vitro experiments in H9C2 cells showed that compared with control cells, both GO and rGO treatment inhibited cell viability, promoted cell apoptosis, and elevated the LDH release. With the increasing radiation absorbed dose, the cytotoxicity of rGO gradually increased. Notably, GO or rGO treatment increased the content of ROS and reduced the mitochondrial membrane potential in H9C2 cells. In vivo experiments also revealed that GO or rGO treatment damaged the myocardial tissues and changed the activities of several myocardial enzymes and the lipid peroxidation indicators in the myocardial tissues.ConclusionGO exhibited a lower cardiotoxicity than rGO due to the structure difference, and the cardiotoxicity of GO and rGO might be mediated by lipid peroxidation, oxidative stress, and mitochondrial dysfunction.

Evidence for a defective mitochondrial membrane in 1,2-dimethylhydrazine-induced colon adenocarcinoma in rat: Enhanced lipid peroxidation potential in vitro

1980 ◽  
Vol 9 (3) ◽  
pp. 237-244 ◽  
Author(s):  
R.S. Rana ◽  
R.H. Stevens ◽  
L. Oberley ◽  
D.P. Loven ◽  
J.M. Graves ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Mitochondrial Membrane ◽  
Colon Adenocarcinoma

scholarly journals A kinetic analysis of the changes in fluorescence on the interaction of 8-anilinonaphthalene-l-sulphonate with submitochondrial particles

1976 ◽  
Vol 158 (2) ◽  
pp. 295-305 ◽  
Author(s):  
N Gains ◽  
A P Dawson
Keyword(s):  
Kinetic Analysis ◽  
Mitochondrial Membrane ◽  
Antimycin A ◽  
Submitochondrial Particles ◽  
Submitochondrial Particle ◽  
Fluorescence Change

A comparison of the fluorescence change on the addition of 8-anilinonaphthalene-1-sulphonate to succinate-energized submitochondrial particles with that on the addition of succinate to submitochondrial particles incubated with 8-anilinonaphthalene-1-sulphonate shows that these changes in fluorescence may be explained solely in terms of 8-anilinonaphthalene-1-sulphonate binding. This comparison does not support the proposal of an 8-anilinonaphthalene-1-sulphonate-monitored change in the conformation of submitochondrial-particle membranes [Brocklehurst, Freedman, Hancock & Radda (1970) Biochem. J.116, 721-731]. The biphasic nature of the decrease in fluorescence, which was found to follow the addition of uncoupler to submitochondrial particles incubated with ATP or succinate, or of antimycin A to submitochondrial particles incubated with succinate, does not support the existence of ‘aplectic’ and ‘symplectic’ states of the mitochondrial membrane [Barrett-Bee & Radda (1972) Biochim, Biophys. Acta 267, 211-215].

Carrier-mediated urea transport across the mitochondrial membrane of an elasmobranch (Raja erinacea) and a teleost (Oncorhynchus mykiss) fish

2008 ◽  
Vol 294 (6) ◽  
pp. R1947-R1957 ◽  
Author(s):  
T. M. Rodela ◽  
J. S. Ballantyne ◽  
P. A. Wright
Keyword(s):  
Oncorhynchus Mykiss ◽  
Mitochondrial Membrane ◽  
Liver Mitochondria ◽  
Reverse Direction ◽  
Maximal Velocity ◽  
Urea Transport ◽  
Submitochondrial Particles ◽  
Raja Erinacea ◽  
Urea Uptake ◽  
High Concentrations

In osmoregulating teleost fish, urea is a minor nitrogen excretory product, whereas in osmoconforming marine elasmobranchs it serves as the major tissue organic solute and is retained at relatively high concentrations (∼400 mmol/l). We tested the hypothesis that urea transport across liver mitochondria is carrier mediated in both teleost and elasmobranch fishes. Intact liver mitochondria in rainbow trout ( Oncorhynchus mykiss) demonstrated two components of urea uptake, a linear component at high concentrations and a phloretin-sensitive saturable component [Michaelis constant ( Km) = 0.58 mmol/l; maximal velocity ( Vmax) = 0.12 μmol·h−1·mg protein−1] at lower urea concentrations (<5 mmol/l). Similarly, analysis of urea uptake in mitochondria from the little skate ( Raja erinacea) revealed a phloretin-sensitive saturable transport ( Km= 0.34 mmol/l; Vmax= 0.054 μmol·h−1·mg protein−1) at low urea concentrations (<5 mmol/l). Surprisingly, urea transport in skate, but not trout, was sensitive to a variety of classic ionophores and respiration inhibitors, suggesting cation sensitivity. Hence, urea transport was measured in the reverse direction using submitochondrial particles in skate. Transport kinetics, inhibitor response, and pH sensitivity were very similar in skate submitochondrial particle submitochondrial particles ( Km= 0.65 mmol/l, Vmax= 0.058 μmol·h−1·mg protein−1) relative to intact mitochondria. We conclude that urea influx and efflux in skate mitochondria is dependent, in part, on a bidirectional proton-sensitive mechanism similar to bacterial urea transporters and reminiscent of their ancestral origins. Rapid equilibration of urea across the mitochondrial membrane may be vital for cell osmoregulation (elasmobranch) or nitrogen waste excretion (teleost).

scholarly journals Decreased glucorticoid sensitivity as a factor of stressogenic shifts in the activity of monoamine oxidase, lipid peroxidation, and behavior in rats

2003 ◽  
Vol 49 (5) ◽  
pp. 48-51 ◽  
Author(s):  
I. A. Volchegorsky ◽  
V. E. Tseilikman ◽  
D. S. Smirnov ◽  
S. A. Ship ◽  
A. V. Borisenkov
Keyword(s):  
Lipid Peroxidation ◽  
Monoamine Oxidase ◽  
Brain Tissue ◽  
Behavioral Disorders ◽  
Immobilization Stress ◽  
Glucocorticoid Hormones ◽  
And Behavior ◽  
The Brain

Four episodes of immobilization stress cause a decrease in the sensitivity to glucocorticoid hormones, followed by anxiogenic be­havioral disorders, enhanced monoamine oxidase-В (МАО-В) activity and simultaneously increased lipid peroxidation (LPO) in the brain tissue of rats. Concurrently, there is an increase in renal МАО-В activity, as well as renal and hepatic accumulation of LPO products. Administration of kenalog (2 mg/kg), a phar­macological analogue of glucocorticoid hormones, prevents the poststress МАО-В activation and LPO and attenuates anxiogen­ic behavioral disorders in the rats.

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