scholarly journals Oxygen toxicity in Astasia

1967 ◽  
Vol 105 (2) ◽  
pp. 813-819 ◽  
Author(s):  
Nicole Bégin-Heick ◽  
J. J. Blum
Keyword(s):  
Carbon Dioxide ◽  
Growth Rate ◽  
Cytochrome C ◽  
Atmospheric Pressure ◽  
Oxygen Toxicity ◽  
Mitochondrial Fraction ◽  
Inhibition Of Growth ◽  
Astasia Longa ◽  
Nadh Cytochrome ◽  
Succinate Oxidase

1. Exposure of Astasia longa to oxygen+carbon dioxide (95:5) at atmospheric pressure leads to an inhibition of growth rate and of respiration. Growth resumes at the normal rate as soon as the oxygenation is discontinued, but respiration recovers more slowly. 2. Mitochondria prepared from cells exposed to oxygen+carbon dioxide (95:5) during growth have considerably decreased activities of succinate–cytochrome c oxidoreductase, NADH–cytochrome c oxidoreductase, succinate dehydrogenase and succinate oxidase activities as compared with mitochondria obtained from cells exposed to air+carbon dioxide (95:5). Cytochrome oxidase activity is not appreciably inhibited by exposure of the cells to 95% oxygen. 3. The mitochondrial fraction of Astasia contains rhodoquinone. The rhodoquinone concentration increases in cells exposed to 95% oxygen. The content of ergosterol-containing compounds also increases in the mitochondria of cells exposed to 95% oxygen. There is little change in the ubiquinone content of the mitochondrial fraction. The ubiquinone of Astasia appears to be ubiquinone-45.

scholarly journals Metabolic changes during phosphate deprivation in Englena in air and in oxygen

1967 ◽  
Vol 105 (2) ◽  
pp. 821-829 ◽  
Author(s):  
J. J. Blum ◽  
Nicole Bégin-Heick
Keyword(s):  
Carbon Dioxide ◽  
Cytochrome C ◽  
Culture Media ◽  
Oxygen Toxicity ◽  
Sole Source ◽  
Ring Closure ◽  
Carotenoid Content ◽  
Phosphate Deprivation ◽  
Nadh Cytochrome ◽  
Phosphate Medium

1. Euglena cells were grown in culture media containing either 20mm-phosphate or 20μm-phosphate, with ethanol or glucose as the sole source of carbon, and gassed with either air+carbon dioxide (95:5) or oxygen+carbon dioxide (95:5) at atmospheric pressure. 2. After growth in low-phosphate medium with ethanol as substrate, the cells developed signs of oxygen toxicity, as indicated by a decreased rate of respiration, a decreased net synthesis of paramylum and a failure to resume growth on replenishment of phosphate. 3. After growth in low-phosphate medium with glucose as substrate, the signs of oxygen toxicity were less apparent. 4. During phosphate deprivation the carotenoid content of Euglena increased more than threefold. This increase was largely prevented by exposure of the cells to oxygen+carbon dioxide (95:5) during growth. Oxygenation appears to interfere with ring closure of the common carotenoid precursor. 5. Mitochondria obtained from Euglena exposed to oxygen during phosphate deprivation, i.e. when signs of oxygen toxicity were evident, had greatly decreased activities of succinate dehydrogenase, succinate–cytochrome c oxidoreductase and NADH–cytochrome c oxidoreductase, compared with mitochondria obtained from Euglena exposed to oxygen in medium containing 20mm-phosphate.

Oxygen toxicity and carbon deprivation in Astasia longa

1970 ◽  
Vol 48 (3) ◽  
pp. 251-258 ◽  
Author(s):  
Nicole Bégin-Heick
Keyword(s):  
Cytochrome C ◽  
Alcohol Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Cellular Respiration ◽  
Endogenous Respiration ◽  
Oxidoreductase Activity ◽  
Oxygen Treatment ◽  
Astasia Longa ◽  
Alcohol Dehydrogenase Activity ◽  
Nadh Cytochrome

The changes in metabolic activity of Astasia longa during oxygen treatment and carbon deprivation were examined. In many respects (growth, cell composition, and some enzymatic activities) the two treatments produce similar effects. Other parameters such as cellular respiration are affected differently. Oxygen treatment inhibits the ethanol-stimulated respiration but affects endogenous respiration very little. At the same time, the total alcohol dehydrogenase activity of the cell is increased at least 10-fold. In starved cells, the endogenous respiration is decreased parallel to the cellular content of carbohydrate reserves, but the ability of the cell to utilize ethanol stays constant. The NADH : cytochrome c oxidoreductase activity of the oxygen-treated cells is decreased by 70% whereas this activity is decreased less than 30% in starved cells. It is proposed that the inhibition of the NADH : cytochrome c oxidoreductase activity is the primary activity affected by oxygen treatment in both acetate- and ethanol-grown cells. The characteristic effects of oxygen treatment on ethanol-grown cells are probably the result of the combination of increased NAD-dependent alcohol dehydrogenase activity and decreased NADH : cytochrome c oxidoreductase activity. Such a modification of these two activities would tend to keep NAD in the reduced state and therefore limit cellular reactions which require oxidized NAD.

Melatonin protects against cadmium-induced oxidative damage in different tissues of rat: a mechanistic insight

2019 ◽  
Vol 2 (2) ◽  
pp. 1-21 ◽  
Author(s):  
Elina Mitra ◽  
Bharati Bhattacharjee ◽  
Palash Kumar Pal ◽  
Arnab Kumar Ghosh ◽  
Sanatan Mishra ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Oxidative Damage ◽  
Protein Carbonyl ◽  
Environmental Pollutant ◽  
Glutathione S Transferase ◽  
Protein Carbonyl Content ◽  
Wide Range ◽  
Liver And Kidney ◽  
Nadh Cytochrome ◽  
Cd Exposure

Cadmium (Cd) is a notorious environmental pollutant known for its wide range of toxicities to organisms. Thus, the present study is designed to examine whether melatonin, a potent antioxidant, protects against Cd-induced oxidative damage in the heart, liver and kidney of rats. Cd treatment at a dose of 0.44 mg/kg for 15 days caused severe damage in all these organs. These included significantly increased activities of SGPT, SGOT, lactate dehydrogenase- 1 and 5 and ALP and levels of total lactate, creatinine, lipid peroxidation, protein carbonyl content and reduced glutathione while the activities of superoxide dismutases, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase along with mitochondrial pyruvate dehydrogenase, isocitrate dehydrogenase, α-keto glutarate dehydrogenase, succinate dehydrogenase, NADH-cytochrome-c-oxidoreductase and cytochrome-c-oxidase were significantly reduced by Cd. However, if melatonin was given orally 30 min before Cd injection, all these alterations induced by Cd were significantly preserved by melatonin. Histological observations also demonstrated that Cd exposure caused cellular lesions, promoting necrotic or apoptotic changes. Notably, all these changes were significantly protected by melatonin. The results suggest that melatonin is a beneficial molecule to ameliorate Cd-induced oxidative damage in the heart, liver and kidney tissues of rats with its powerful antioxidant capacity, heavy metal chelating activity and competition of binding sites with Cd to the GSH and catalase.

Silver Chloride/Triphenylphosphine-Promoted Carboxylation of Arylboronic Esters with Carbon Dioxide at Atmospheric Pressure

2018 ◽  
Vol 14 (8) ◽  
Author(s):  
Zhi-Hua Zhou ◽  
Chun-Xiang Guo ◽  
Jia-Ning Xie ◽  
Kai-Xuan Liu ◽  
Liang-Nian He
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Pressure ◽  
Silver Chloride

scholarly journals DELETIONS OF THE ISO-1-CYTOCHROME c AND ADJACENT GENES OF YEAST: DISCOVERY OF THE OSM1 GENE CONTROLLING OSMOTIC SENSITIVITY

Genetics ◽  
1978 ◽  
Vol 89 (4) ◽  
pp. 653-665
Author(s):  
Arjun Singh ◽  
Fred Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Uv Light ◽  
Yeast Saccharomyces Cerevisiae ◽  
Osmotic Sensitivity ◽  
Inhibition Of Growth

ABSTRACT Some of the deletions in the yeast Saccharomyces cerevisiae that encompass the CYC1 gene, which determines iso-1-cytochrome c, extend into the OSM1 gene, causing inhibition of growth on hypertonic media, and into the RAD7 gene, causing sensitivity to UV light. Two deletions (cyc1-363 and cyc1-367) encompass only the CYC1 gene, two deletions (cyc1-366 and cyc1-368) encompass the CYC1 and OSM1 genes, three deletions (cyc1-1, cyc1-364 and cyc1-365) encompass the CYC1, OSM1 and RAD7 genes, while none of the deletions extend into the closely linked SUP4 gene.

scholarly journals Properties of a cytochrome c-enriched light particulate fraction isolated from the photosynthetic bacterium Rhodopseudomonas spheroides

1978 ◽  
Vol 174 (1) ◽  
pp. 267-275 ◽  
Author(s):  
J Barrett ◽  
C N Hunter ◽  
O T G Jones
Keyword(s):  
Cytochrome C ◽  
Sodium Dodecyl ◽  
Photosynthetic Bacterium ◽  
Particulate Fraction ◽  
Cytochrome C Reductase ◽  
Cytochrome C2 ◽  
Succinate Cytochrome C Reductase ◽  
Bulk Membrane ◽  
Nadh Cytochrome ◽  
Rhodopseudomonas Spheroides

Differential centrifugation of suspensions of French-press-disrupted Rhodopseudomonas spheroides yielded a light particulate fraction that was different in many properties from the bulk membrane fraction. It was enriched in cytochrome c and had a low cytochrome b content. When prepared from photosynthetically grown cells this fraction had a very low specific bacteriochlorophyll content. The cytochrome c of the light particles differed in absorption maxima at 77K from cytochrome c2 attached to membranes; there was pronounced splitting of the alpha-band, as is found in cytochrome c2 free in solution. Potentiometric titration at A552–A540 showed the presence of two components that fitted an n = 1 titration; one component had a midpoint redox potential of +345mV, like cytochrome c2 in solution, and the second had E0′ at pH 7.0 of +110 mV, and they were present in a ratio of approx. 2:3. Difference spectroscopy at 77K showed that the spectra of the two components were very similar. More of a CO-binding component was present in particles from photosynthetically grown cells. Light membranes purified by centrifugation on gradients of 5–60% (w/w) sucrose retained the two c cytochromes; they contained no detectable succinate-cytochrome c reductase or bacteriochlorophyll and very little ubiquinone, but they contained NADH-cytochrome c reductase and some phosphate. Electrophoresis on sodium dodecyl sulphate/polyacrylamide gels showed that the light membranes of aerobically and photosynthetically grown cells were very similar and differed greatly from other membrane fractions of R. spheroides.

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