scholarly journals Alteration of Pseudomonas aeruginosa respiration by 4-(1-adamantyl)-phenol derivative

Biologija ◽  
2018 ◽  
Vol 64 (3) ◽  
Author(s):  
Daria M. Dudikova ◽  
Nina O. Vrynchanu ◽  
Valentyna I. Nosar
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Respiratory Chain ◽  
Structural Integrity ◽  
Respiratory Control ◽  
Endogenous Respiration ◽  
Phenol Derivative ◽  
Succinate Oxidation ◽  
Intact Cells

Derivatives of 4-(1-adamantyl)-phenol are a promising class of antimicrobials affecting the structural integrity and functions of the bacterial cell membrane. The functioning of Pseudomonas aeruginosa respiratory chain and related system of oxidative phosphorylation was investigated before and after treatment with a derivative of 4-(1-adamantyl)-phenol (compound KVM-97). Oxygen consumption was measured polarographically with a Clark-type oxygen electrode. KVM-97 was tested at 0.5× and 1.0× MIC (minimum inhibitory concentration). Specific substrates of the respiratory chain (either 3.0 mM glutamate with 2.0 mM malonate or 3.0 mM succinate with 5.0 μM rotenone) were used. All reactions were stimulated by addition of ADP (0.2 mmol). It was found that at tested concentrations, KVM-97 inhibited the endogenous respiration and substrate oxidation in P. aeruginosa cells. The inhibiting effect was dose-dependent and more pronounced with succinate oxidation rather than glutamate oxidation. The respiratory control index value (RCI) in compound-treated cells was in average 1.5 times lower compared to the intact cells. The decrease in the RCI was related to changing the oxygen uptake rates in state 3 and state 4, which indicate the uncoupling of respiration and oxidative phosphorylation. The data obtained showed that 4-(1-adamantyl)-phenol derivative inhibits oxygen consumption and has uncoupling effects in P. aeruginosa cells.

scholarly journals Senescence-associated changes in respiration and oxidative phosphorylation in primary human fibroblasts

2004 ◽  
Vol 380 (3) ◽  
pp. 919-928 ◽  
Author(s):  
Eveline HUTTER ◽  
Kathrin RENNER ◽  
Gerald PFISTER ◽  
Petra STÖCKL ◽  
Pidder JANSEN-DÜRR ◽  
...  
Keyword(s):  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
Replicative Senescence ◽  
Citrate Synthase ◽  
Human Fibroblasts ◽  
Respiratory Control ◽  
Compensatory Mechanisms ◽  
Intact Cells ◽  
Atp Production ◽  
Human Diploid Fibroblasts

Limitation of lifespan in replicative senescence is related to oxidative stress, which is probably both the cause and consequence of impaired mitochondrial respiratory function. The respiration of senescent human diploid fibroblasts was analysed by highresolution respirometry. To rule out cell-cycle effects, proliferating and growth-arrested young fibroblasts were used as controls. Uncoupled respiration, as normalized to citrate synthase activity, remained unchanged, reflecting a constant capacity of the respiratory chain. Oligomycin-inhibited respiration, however, was significantly increased in mitochondria of senescent cells, indicating a lower coupling of electron transport with phosphorylation. In contrast, growth-arrested young fibroblasts exhibited a higher coupling state compared with proliferating controls. In intact cells, partial uncoupling may lead to either decreased oxidative ATP production or a compensatory increase in routine respiration. To distinguish between these alternatives, we subtracted oligomycin-inhibited respiration from routine respiration, which allowed us to determine the part of respiratory activity coupled with ATP production. Despite substantial differences in the respiratory control ratio, ranging from 4 to 11 in the different experimental groups, a fixed proportion of respiratory capacity was maintained for coupled oxidative phosphorylation in all the experimental groups. This finding indicates that the senescent cells fully compensate for increased proton leakage by enhanced electron-transport activity in the routine state. These results provide a new insight into age-associated defects in mitochondrial function and compensatory mechanisms in intact cells.

scholarly journals The Effect of Narcotics on the Endogenous Respiration and Succinate Oxidation in Oyster Muscle

1948 ◽  
Vol 27 (2) ◽  
pp. 504-512
Author(s):  
George Frederick Humphrey
Keyword(s):  
Salicylic Acid ◽  
Oxygen Consumption ◽  
Benzoic Acid ◽  
Succinic Acid ◽  
Chloral Hydrate ◽  
Endogenous Respiration ◽  
Succinate Oxidation ◽  
Adductor Muscles

The action of the following compounds on homogenates of the adductor muscles of Saxostrea commercialis was studied: urethane, phenyl urethane, chloral hydrate, salicylic acid, morphine, caffeine, barbitone, benzoic acid, salicylamide and benzamide.It was found that, except for 0·05 M urethane, the endogenous oxygen consumption was reduced by all these compounds when present in concentrations ranging from o·001 to 0·05M. The oxidation of succinic acid was partially inhibited by these substances.These findings are discussed in relation to similar studies on other tissues.

Oxidative phosphorylation in cardiac infarct. Effect of glucose-KCl-insulin solution

1965 ◽  
Vol 209 (2) ◽  
pp. 371-375 ◽  
Author(s):  
Edmundo Calva ◽  
Adela Mujica ◽  
Abdo Bisteni ◽  
Demetrio Sodi-Pallares
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Respiratory Control ◽  
Low Oxygen ◽  
Normal Limits ◽  
Functional Aspects ◽  
Insulin Solution ◽  
Effect Of Glucose ◽  
Infarcted Tissue ◽  
Electrocardiographic Abnormalities

Myocardial infarction was produced in dogs by ligature of the anterior descending coronary artery. Sarcosomes were isolated from normal and infarcted tissue. Oxygen consumption was followed polarographically and adenosine triphosphate was measured as glucose 6-phosphate. One group of animals received a continuous infusion of glucose for 12 hr; another group received "polarizing solution" (glucose-KCl-insulin). Sarcosomes from the first had a low oxygen consumption, no respiratory control, and no oxidative phosphorylation. In contrast, the administration of glucose-KCl-insulin solution maintained practically within normal limits these functional aspects of the sarcosomes. The reversal of electrocardiographic abnormalities by the administration of the polarizing solution coincided with improvement of such biochemical functions. Anesthesia and surgical handling did not appear to modify the behavior of the sarcosomes.

Sulphide oxidation and oxidative phosphorylation in the mitochondria of the lugworm

1997 ◽  
Vol 200 (1) ◽  
pp. 83-92 ◽  
Author(s):  
S Vökel ◽  
M K Grieshaber
Keyword(s):  
Oxygen Consumption ◽  
Cytochrome C ◽  
Oxidative Phosphorylation ◽  
Cytochrome C Oxidase ◽  
Electron Flow ◽  
Respiratory Control ◽  
Sulphide Oxidation ◽  
Atp Production ◽  
Sulphide Concentration ◽  
Flow Through

Oxygen consumption, ATP production and cytochrome c oxidase activity of isolated mitochondria from body-wall tissue of Arenicola marina were measured as a function of sulphide concentration, and the effect of inhibitors of the respiratory complexes on these processes was determined. Concentrations of sulphide between 6 and 9 µmol l-1 induced oxygen consumption with a respiratory control ratio of 1.7. Production of ATP was stimulated by the addition of sulphide, reaching a maximal value of 67 nmol min-1 mg-1 protein at a sulphide concentration of 8 µmol l-1. Under these conditions, 1 mole of ATP was formed per mole of sulphide consumed. Higher concentrations of sulphide led to a decrease in ATP production until complete inhibition occurred at approximately 50 µmol l-1. The production of ATP with malate and succinate was stimulated by approximately 15 % in the presence of 4 µmol l-1 sulphide, but decreased at sulphide concentrations higher than 15­20 µmol l-1. Cytochrome c oxidase was also inhibited by sulphide, showing half-maximal inhibition at 1.5 µmol l-1 sulphide. Sulphide-induced ATP production was inhibited by antimycin, cyanide and oligomycin but not by rotenone or salicylhydroxamic acid. The present data indicate that sulphide oxidation is coupled to oxidative phosphorylation solely by electron flow through cytochrome c oxidase, whereas the alternative oxidase does not serve as a coupling site. At sulphide concentrations higher than 20 µmol l-1, oxidation of sulphide serves mainly as a detoxification process rather than as a source of energy.

Pseudomonas aeruginosa lipopolysaccharide: an uncoupler of mitochondrial oxidative phosphorylation

1975 ◽  
Vol 21 (6) ◽  
pp. 877-883 ◽  
Author(s):  
G. Gordon Greer ◽  
F. H. Milazzo
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Respiratory Control ◽  
Substrate Oxidation ◽  
Respiratory Control Ratio ◽  
Mitochondrial Oxidative Phosphorylation

The addition of Pseudomonas aeruginosa KCIIR LPS to respiring mitochondria stimulated the rate of substrate oxidation, reduced the respiratory control ratio, stimulated oxygen uptake in state 4, and released the inhibition imposed upon state 3 by atractyloside. It was concluded that LPS acted as an uncoupler of oxidative phosphorylation and that it produced effects similar to those observed with the classical uncoupler 2,4-dinitrophenol.

scholarly journals Imaging Cuprizone-Induced Mitochondrial Dysfunction

2020 ◽  
Author(s):  
Lucille A. Ray ◽  
Gardenia Pacheco ◽  
Alexandra Taraboletti ◽  
Michael C. Konopka ◽  
Leah P. Shriver
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Dynamics ◽  
Initial Increase ◽  
Intact Cells ◽  
Hepatic Cells ◽  
Transport Chain ◽  
Consumption Rates ◽  
Transcriptional Changes

AbstractCuprizone is a copper chelator that induces mitochondrial dysfunction in myelin-producing oligodendrocytes and hepatic cells. Inhibition of oxidative phosphorylation has been proposed as a potential mechanism, but the exact relationship between shape changes and metabolic alterations is not well-understood. Here we explore how mitochondrial shape influences oxidative phosphorylation rates by performing simultaneous imaging and respiration measurements within intact cells. We observed that MO3.13 cells exposed to cuprizone undergo an initial increase in respiration followed by mitochondrial dysfunction and genetic dysregulation within 8 hours. Oxygen consumption was measured within 30 minutes of treatment and found to be elevated. This increase was followed by swelling of mitochondria over the first 8 hours, but preceded cell death by 24 hours. A transcriptomic analysis of early changes in cellular gene expression identified alterations within the electron transport chain, stress response pathways, and mitochondrial dynamics compared to control cells. These results suggest that pathological mitochondrial swelling is associated with increased oxygen consumption rates leading to transcriptional changes in respiratory complexes and ultimately mitochondrial failure.

PIGEON MUSCLE MITOCHONDRIA: ION CONCENTRATIONS, OXIDATIVE PHOSPHORYLATION, SWELLING, AND EXTRAPARTICULATE SPACE

1963 ◽  
Vol 41 (1) ◽  
pp. 2529-2542 ◽  
Author(s):  
G. J. Marcus ◽  
J. F. Manery
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Phosphorylation ◽  
Respiratory Control ◽  
Sodium Potassium ◽  
Density Measurements ◽  
Muscle Mitochondria ◽  
Ion Concentrations ◽  
Heat Stable ◽  
Control Respiration ◽  
Mitochondrial Volume

Metabolically active mitochondria were isolated from pigeon breast muscle in cold 0.45 M sucrose with ATP, EDTA, and tris buffer at pH 7.4. Fresh mitochondria were analyzed for sodium, potassium, nitrogen, iron, and water. They were morphologically intact and showed respiratory control, respiration being limited by the phosphate acceptor and stimulated by dinitrophenol. The respiratory rate was the same in the Warburg respirometer as that in the polarograph chamber; no effect of agitation was observed. The rates of oxygen consumption over short periods of time were 30–40 μ atoms per hour per mg N for α-keto-glutarate and glutamate, 16 for malate, and 1.3 for β-OH butyrate; except in the last case, satisfactory P/O ratios were obtained. A soluble, heat-stable muscle factor, not precipitated at 100,000 × G, stimulated respiration with each substrate but did not affect phosphorylation. From optical density measurements of muscle mitochondria they appeared to behave as moderately good osmometers; only slight swelling occurred during oxidative phosphorylation, but this increased somewhat when respiration ceased. The osmotic dead space was estimated at 60% of the mitochondrial volume. With polyvinylpyrrolidone the extraparticulate space was found to be 27.8 ± 1.8%.

scholarly journals Effects of sodium and potassium ions on oxidative phosphorylation in relation to respiratory control by a cell-membrane adenosine triphosphatase

1965 ◽  
Vol 97 (2) ◽  
pp. 523-531 ◽  
Author(s):  
DM Blond ◽  
R Whittam
Keyword(s):  
Oxygen Consumption ◽  
Cell Membrane ◽  
Oxidative Phosphorylation ◽  
Adenosine Triphosphatase ◽  
Respiratory Control ◽  
Enzymic Activity ◽  
Cellular Respiration ◽  
Physiological Concentration ◽  
A Cell ◽  
K Concentration

1. A study has been made of the oxygen consumption of kidney homogenates in relation to the ADP concentration as regulated by the cell-membrane adenosine triphosphatase. Stimulation of this enzymic activity by Na(+) and K(+) caused parallel increases in oxygen consumption and ADP concentration. Similarly, inhibition with ouabain caused a parallel fall. The membrane adenosine triphosphatase concerned in active transport therefore appears to regulate respiration through its control of ADP concentration. 2. The respiration of homogenates and mitochondria was also stimulated by K(+) in a way independent of adenosine-triphosphatase activity. It was shown that K(+) facilitates oxidative phosphorylation and the respiratory response to ADP. A K(+) concentration of 25-50mm was needed for maximum oxidative phosphorylation in the presence of physiological concentration of Na(+). Na(+) counteracted K(+) in the effects on mitochondria. It is concluded that K(+) regulates cellular respiration at two structures, one directly in mitochondria, and the second indirectly through control of ADP production at the cell membrane.

scholarly journals Stimulation of Menaquinone-Dependent Electron Transfer in the Respiratory Chain of Bacillus subtilis by Membrane Energization

2002 ◽  
Vol 184 (19) ◽  
pp. 5339-5347 ◽  
Author(s):  
N. Azarkina ◽  
A. A. Konstantinov
Keyword(s):  
Electron Transfer ◽  
Bacillus Subtilis ◽  
Respiratory Chain ◽  
Inhibitory Effect ◽  
Endogenous Respiration ◽  
Bacterial Cells ◽  
Succinate Oxidation ◽  
Endogenous Substrates ◽  
Energy Dependent ◽  
Membrane Energization

ABSTRACT At a pH of ≤7, respiration of Bacillus subtilis cells on endogenous substrates shut down almost completely upon addition of an uncoupler (carbonyl cyanide m-chlorophenylhydrazone [CCCP]) and a K+-ionophore (valinomycin). The same effect was observed with cell spheroplasts lacking the cell wall. The concentration of CCCP required for 50% inhibition of the endogenous respiration in the presence of K+-valinomycin was below 100 nM. Either CCCP or valinomycin alone was much less efficient than the combination of the two. The inhibitory effect was easily reversible and depended specifically on the H+ and K+ concentrations in the medium. Similar inhibition was observed with respect to the reduction of the artificial electron acceptors 2,6-dichlorophenolindophenol (DCPIP) and N,N,N′,N′-tetramethyl-p-phenylenediamine cation (TMPD+), which intercept reducing equivalents at the level of menaquinol. Oxidation of the reduced DCPIP or TMPD in the bacterial cells was not sensitive to uncoupling. The same loss of the electron transfer activities as induced by the uncoupling was observed upon disruption of the cells during isolation of the membranes; the residual activities were not further inhibited by the uncoupler and ionophores. We conclude that the menaquinone-dependent electron transfer in the B. subtilis respiratory chain is facilitated, thermodynamically or kinetically, by membrane energization. A requirement for an energized state of the membrane is not a specific feature of succinate oxidation, as proposed in the literature, since it was also observed in a mutant of B. subtilis lacking succinate:quinone reductase as well as for substrates other than succinate. Possible mechanisms of the energy-dependent regulation of menaquinone-dependent respiration in B. subtilis are discussed.

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