scholarly journals Continuous exposure to high concentrations of nitric oxide leads to persistent inhibition of oxygen consumption by J774 cells as well as extraction of oxygen by the extracellular medium

2000 ◽  
Vol 346 (2) ◽  
pp. 407-412 ◽  
Author(s):  
Antonia ORSI ◽  
Belén BELTRÁN ◽  
Emilio CLEMENTI ◽  
Katarina HALLÉN ◽  
Martin FEELISCH ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Oxygen Consumption ◽  
Chemical Interaction ◽  
Continuous Exposure ◽  
Cell Respiration ◽  
Extracellular Medium ◽  
Pathological Conditions ◽  
J774 Cells ◽  
High Concentrations ◽  
Complex I Activity

Nitric oxide (NO) plays a key role in many physiological and pathophysiological events, including the control of cell respiration. Both reversible and irreversible inhibition of mitochondrial respiration have been reported following the generation of NO by cells. We have exposed the murine macrophage cell line J774 to high concentrations of NO, such as are generated in some pathological conditions, and determined their effect on oxygen consumption. We observed a persistent inhibition of respiration which was due to a redox-dependent, progressive inhibition of complex I activity. No other enzyme of the respiratory chain was inhibited in this way. At the same time, we detected a paradoxical removal of oxygen by the extracellular medium. This removal was due to a chemical interaction between dissolved oxygen and NO-related species released from cells exposed to NO. A similar removal of oxygen by the cell supernatant also occurred following activation of cells with cytokines and bacterial products. Thus, the amounts of NO generated during pathological conditions may contribute to tissue hypoxia both by inhibiting cell respiration and by promoting removal of oxygen from the extracellular medium.

ACE Inhibitors Promote Nitric Oxide Accumulation to Modulate Myocardial Oxygen Consumption

Circulation ◽  
1997 ◽  
Vol 95 (1) ◽  
pp. 176-182 ◽  
Author(s):  
Xiaoping Zhang ◽  
Yi-Wu Xie ◽  
Alberto Nasjletti ◽  
Xiaobin Xu ◽  
Michael S. Wolin ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Oxygen Consumption ◽  
Ace Inhibitors ◽  
Myocardial Oxygen Consumption

scholarly journals CELL RESPIRATION STUDIES

1927 ◽  
Vol 46 (1) ◽  
pp. 43-51
Author(s):  
Blake C. Wilbur ◽  
Geneva A. Daland ◽  
John Cohen
Keyword(s):  
Oxygen Consumption ◽  
Whole Blood ◽  
Repeated Measurements ◽  
Closed Space ◽  
Cell Respiration ◽  
Chemical Substances ◽  
Normal Individuals ◽  
Tissue Cells

A description is given of a closed space respiration apparatus which can be used to determine the amount of gas used or liberated by living blood or tissue cells, or chemical substances. Continuous observations can be made and repeated measurements recorded without interrupting the vital processes or destroying the cells. Studies of the oxygen consumption by whole blood in normal individuals and in patients with leucocytosis and myelogenous leucemia, as well as by white cells suspended in plasma, will be reported in subsequent papers.

DNA Methylation Changes Induced in Rice by Exposure to High Concentrations of the Nitric Oxide Modulator, Sodium Nitroprusside

2015 ◽  
Vol 33 (5) ◽  
pp. 1428-1440 ◽  
Author(s):  
Xiufang Ou ◽  
Tingting Zhuang ◽  
Wenchao Yin ◽  
Yiling Miao ◽  
Bo Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Dna Methylation ◽  
Sodium Nitroprusside ◽  
High Concentrations

scholarly journals The role of interleukin 12 and nitric oxide in the development of spontaneous autoimmune disease in MRL/MP-lpr/lpr mice.

1996 ◽  
Vol 183 (4) ◽  
pp. 1447-1459 ◽  
Author(s):  
F P Huang ◽  
G J Feng ◽  
G Lindop ◽  
D I Stott ◽  
F Y Liew
Keyword(s):  
Nitric Oxide ◽  
Autoimmune Disease ◽  
Cultured Cells ◽  
Daily Injection ◽  
Interleukin 12 ◽  
No Production ◽  
Necrosis Factor Alpha ◽  
Ifn Gamma ◽  
Peritoneal Cells ◽  
High Concentrations

MRL/MP-lpr/lpr (MRL/lpr) mice develop a spontaneous autoimmune disease. Serum from these mice contained significantly higher concentrations of nitrite/nitrate than serum from age-matched control MRL/MP-+/+ (MRL/+), BALB/c or CBA/6J mice. Spleen and peritoneal cells from MRL/lpr mice also produced significantly more nitric oxide (NO) than those from the control mice when cultured with interferon (IFN) gamma and lipopolysaccharide (LPS) in vitro. It is interesting to note that peritoneal cells from MRL/lpr mice also produced markedly higher concentrations of interleukin (IL) 12 than those from MRL/+ or BALB/c mice when cultured with same stimuli. It is striking that cells from MRL/lpr mice produced high concentrations of NO when cultured cells from MRL/+ or BALB/c mice. The enhanced NO synthesis induced by IFN-gamma/LPS was substantially inhibited by anti-IL-12 antibody. In addition, IL-12-induced NO production can also be markedly inhibited by anti-IFN-gamma antibody, but only weakly inhibited by anti-tumor necrosis factor alpha antibody. The effect of IL-12 on NO production was dependent on the presence of natural killer and possibly T cells. Serum from MRL/lpr mice contained significantly higher concentrations of IL-12 compared with those of MRL/+ or BALB/c control mice. Daily injection of recombinant IL-12 led to increased serum levels of IFN-gamma and NO metabolites, and accelerated glomerulonephritis in the young MRL/lpr mice (but not in the MRL/+ mice) compared with controls injected with phosphate-buffered saline alone. These data, together with previous finding that NO synthase inhibitors can ameliorate autoimmune disease in MRL/lpr mice, suggest that high capacity of such mice to produce IL-12 and their greater responsiveness to IL-12, leading to the production of high concentrations of NO, are important factors in this spontaneous model of autoimmune disease.

The Effect of High Concentrations of Ethylene on Seed Germination of Douglas Fir (Pseudotsugamenziesii (Mirb.) Franco)

1975 ◽  
Vol 5 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Carey Borno ◽  
Iain E. P. Taylor
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Douglas Fir ◽  
Control Treatment ◽  
Continuous Exposure ◽  
Short Term ◽  
Short Term Exposure ◽  
High Concentrations

Stratified, imbibed Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) seeds were exposed to 100% ethylene for times between 0 and 366 h. Germination rate and germination percentage were increased by treatments up to 48 h. The 12-h treatment gave largest stimulation; 30% enhancement of final germination percentage over control. Treatment for 96 h caused increased germination rate for the first 5 days but reduced the germination percentage. Germinants were subject to continuous exposure to atmospheres containing 0.1 – 200 000 ppm ethylene in air, but it did not stimulate growth, and the gas was inhibitory above 100 ppm. Although some effects of high concentrations of ethylene may have been due to the lowering of oxygen supplies, this alone was insufficient to account for the full inhibitory effect. The mechanism of stimulation by short-term exposure to ethylene is discussed.

scholarly journals Induction of nitric oxide synthesis in J774 cells lowers intracellular glutathione: effect of modulated glutathione redox status on nitric oxide synthase induction

1997 ◽  
Vol 322 (2) ◽  
pp. 477-481 ◽  
Author(s):  
John S. HOTHERSALL ◽  
Fernando Q. CUNHA ◽  
Guy H. NEILD ◽  
Alberto A. NOROHNA-DUTRA
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
De Novo ◽  
Redox Status ◽  
No Production ◽  
Duration Of Treatment ◽  
Intracellular Glutathione ◽  
J774 Cells ◽  
Oxide Synthase ◽  
Glutathione Redox

Under pathological conditions, the induction of nitric oxide synthase (NOS) in macrophages is responsible for NO production to a cytotoxic concentration. We have investigated changes to, and the role of, intracellular glutathione in NO production by the activated murine macrophage cell line J774. Total glutathione concentrations (reduced, GSH, plus the disulphide, GSSG) were decreased to 45% of the control 48 h after cells were activated with bacterial lipopolysaccharide plus interferon γ. This was accompanied by a decrease in the GSH/GSSG ratio from 12:1 to 2:1. The intracellular decrease was not accounted for by either GSH or GSSG efflux; on the contrary, rapid export of glutathione in control cells was abrogated during activation. The loss of intra- and extracellular glutathione indicates either a decrease in synthesis de novo, or an increase in utilization, rather than competition for available NADPH. All changes in activated cells were prevented by pretreatment with the NOS inhibitor l-N-(1-iminoethyl)ornithine. Basal glutathione levels in J774 cells were manipulated by pretreatment with (1) buthionine sulphoximine (glutathione synthase inhibitor), (2) acivicin (γ-glutamyltranspeptidase inhibitor), (3) bromo-octane (glutathione S-transferase substrate) and (4) diamide/zinc (thiol oxidant and glutathione reductase inhibitor). All treatments significantly decreased the output of NO following activation. The degree of inhibition was dependent on (i) duration of treatment prior to activation, (ii) rate of depletion or subsequent recovery and (iii) thiol end product. The level of GSH did not significantly affect the production of NO, after induction of NOS. Thus, glutathione redox status appears to plays an important role in NOS induction during macrophage activation.

Carbon Monoxide-Neuroglobin Axis Targeting Metabolism Against Neuroinflammation

2021 ◽  
Author(s):  
Daniela Dias-Pedroso ◽  
José S. Ramalho ◽  
Vilma A. Sardão ◽  
John G. Jones ◽  
Carlos C. Romão ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Inflammatory Response ◽  
Microglial Cell ◽  
Cell Metabolism ◽  
Competent Cell ◽  
Metabolic Shift ◽  
Anti Inflammatory ◽  
Inflammatory Effect

Abstract Microglia are the immune competent cell of the central nervous system (CNS), promoting brain homeostasis and regulating inflammatory response against infection and injury. Chronic or exacerbated neuroinflammation is a cause of damage in several brain pathologies. Endogenous carbon monoxide (CO), produced from the degradation of heme, is described as anti-apoptotic and anti-inflammatory in several contexts, including in the CNS. Neuroglobin (Ngb) is a haemoglobin-homologous protein, which upregulation triggers antioxidant defence and prevents neuronal apoptosis. Thus, we hypothesized a crosstalk between CO and Ngb, in particular, that the anti-neuroinflammatory role of CO in microglia depends on Ngb. A novel CO-releasing molecule (ALF826) based on molybdenum was used for delivering CO in microglial culture.BV-2 mouse microglial cell line was challenged with lipopolysaccharide (LPS) for triggering inflammation, and after 6h ALF826 was added. CO exposure limited inflammation by decreasing inducible nitric oxide synthase (iNOS) expression and the production of nitric oxide (NO) and tumour necrosis factor-a (TNF-a), and by increasing interleukine-10 (IL-10) release. CO-induced Ngb upregulation correlated in time with CO’s anti-inflammatory effect. Moreover, knocking down Ngb reversed the anti-inflammatory effect of CO, suggesting that dependents on Ngb expression. CO-induced Ngb upregulation was independent on ROS signalling, but partially dependent on the transcriptional factor SP1. Finally, microglial cell metabolism is also involved in the inflammatory response. In fact, LPS treatment decreased oxygen consumption in microglia, indicating a switch to glycolysis, which is associated with a proinflammatory. While CO treatment increased oxygen consumption, reverting LPS effect and indicating a metabolic shift into a more oxidative metabolism. Moreover, in the absence of Ngb this phenotype was no longer observed, indicating Ngb is needed for CO’s modulation of microglial metabolism. Finally, the metabolic shift induced by CO did not depend on alteration of mitochondrial population. In conclusion, neuroglobin emerges for the first time as a key player for CO signalling against exacerbated neuroinflammation in microglia.

Intracellular distribution of lead in Tetrahymena during continuous exposure to the metal

1979 ◽  
Vol 39 (1) ◽  
pp. 383-396
Author(s):  
J.R. Nilsson
Keyword(s):  
Cell Growth ◽  
Growth Medium ◽  
Food Vacuole ◽  
Continuous Exposure ◽  
Organic Growth ◽  
Food Vacuoles ◽  
Entire Cell ◽  
Membrane Bound ◽  
Lag Period ◽  
High Concentrations

Lead acetate (0.1–0.2%) forms a precipitate with the organic growth medium. The Tetrahymena cells ingest this lead-containing precipitate and cell growth is resumed after a variable lag period. Ingested lead is observed as electron-dense material in food vacuoles. Soon after exposure, cytoplasmic lead (preserved with certain fixation only) is revealed as electron-dense particles in cilia and in a halo around digestive vacuoles. Later the lead particles pervade the entire cell but after the lag period they are confined to membrane-bound spaces. In dilute growth medium, high concentrations of lead inhibit food-vacuole formation and cell growth. Under these conditions lead is deposited in alveoli of the pellicle and is also found in autophagic vacuoles and other membrane-limited structures. The study has revealed that lead enters Tetrahymena through the membrane of digestive vacuoles and through the cell surface. The change in distribution of lead during the lag period indicates that a mechanism is activated for removal of lead into membrane-bound spaces. The final storage of lead seems to be in lysosomes.

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