Assessment of antioxidant and antiproliferative properties of spinach plants grown under low oxygen availability

The hatching of rainbow trout (Salmo gairdneri) embryos can be stimulated by subjecting them to low oxygen partial pressures [Formula: see text] during the final days of incubation or delayed by elevating [Formula: see text]. Most embryos develop the ability to hatch between days 26 and 27 of incubation at 12 °C. During this time, similar hatching frequencies are obtained at any [Formula: see text] below a critical value in the 94–135 mm Hg (6.5–9.3 mg/L) range (1 mm Hg = 133.322 Pa). The [Formula: see text] required for continued incubation increases with developmental time such that hatching cannot be delayed beyond day 30 at 12 °C. These results indicate that oxygen availability influences the time at which trout embryos hatch and that hatching occurs when hatchable embryos are confronted with an ambient [Formula: see text] that is inadequate to satisfy aerobic metabolic requirements.

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Metabolic enzyme activities in swimming muscle of medusae: is the scaling of glycolytic activity related to oxygen availability?

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315405011537 ◽

2005 ◽

Vol 85 (3) ◽

pp. 603-611 ◽

Cited By ~ 19

Author(s):

Erik V. Thuesen ◽

Kelly D. McCullough ◽

James J. Childress

Keyword(s):

Body Size ◽

Citrate Synthase ◽

Krebs Cycle ◽

Glycolytic Enzyme ◽

Oxygen Availability ◽

Metabolic Enzyme ◽

Low Oxygen ◽

Cycle Enzyme ◽

Glycolytic Activity ◽

Two Populations

This study compared the scaling of the glycolytic enzyme lactate dehydrogenase (LDH) and the Krebs cycle enzyme citrate synthase (CS) in the swimming muscle and tentacle tissue of the mesopelagic coronate scyphomedusa Periphylla periphylla in two populations living under different oxygen minimum layer conditions. The LDH and CS activities in these tissues of two other coronate scyphomedusae (Paraphyllina ransoni and Periphyllopsis galatheae) and the bathypelagic narcomedusa Aegina citrea were also studied. The scaling of these two enzymes along with total protein was investigated in whole organism homogenates of the surface-living scyphomedusa Aurelia labiata. Mass-specific LDH activities in swimming muscle showed positive scaling in relation to body size in Periphylla periphylla collected off California and Hawaii. Mass-specific LDH activities in tentacle tissue increased with regards to increasing mass only in specimens of P. periphylla collected off California. The LDH values of the scaling coefficient, b, in swimming muscle and tentacle were significantly higher in P. periphylla collected in the low oxygen waters off California than from those collected off the Hawaiian Islands in a higher oxygen environment. The LDH showed a significant decrease with body size in Aegina citrea swimming muscle and in Aurelia labiata whole animal homogenates. The largest species in this study, Periphyllopsis galatheae, had LDH activities similar to the smallest specimens of Periphylla periphylla. The results of this study suggest that the scaling of glycolytic activity is related to oxygen availability for P. periphylla. In Aurelia labiata, which is only exposed to episodic hypoxia, and Aegina citrea, scaling of glycolytic activity is not affected by oxygen availability.

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Some Effects of Temporary Exposure to Low Dissolved Oxygen Levels on Pacific Salmon Eggs

Journal of the Fisheries Research Board of Canada ◽

10.1139/f58-013 ◽

1958 ◽

Vol 15 (2) ◽

pp. 229-250 ◽

Cited By ~ 91

Author(s):

D. F. Alderdice ◽

W. P. Wickett ◽

J. R. Brett

Keyword(s):

Oxygen Consumption ◽

Dissolved Oxygen ◽

Oxygen Demand ◽

Oxygen Availability ◽

Oncorhynchus Keta ◽

Hatching Rate ◽

Oxygen Level ◽

Low Oxygen ◽

Low Dissolved Oxygen ◽

Oxygen Levels

Eggs of the chum salmon (Oncorhynchus keta) were exposed to various constant levels of dissolved oxygen for a period of seven days. The procedure was repeated with fresh egg samples at various developmental stages. Temperatures were constant at 10 °C. from fertilization to hatching. Estimates of oxygen consumption uninhibited by low dissolved oxygen levels were obtained at various stages of egg development for whole eggs and also on the basis of the weight of larvae, excluding the yolk. Eggs were most sensitive to hypoxia between 100–200 Centigrade degree-days and compensated for reduced oxygen availability by reducing the oxygen demand and rate of development. Very low oxygen levels at early incubation stages resulted in the production of monstrosities. At about the time the circulatory system becomes functional the compensatory reduction in rate of growth under hypoxial conditions is reduced, but eggs no longer survive extreme hypoxial conditions. Eggs subjected to low dissolved oxygen levels just prior to hatching hatch prematurely at a rate dependent on the degree of hypoxia. The maximum premature hatching rate corresponded approximately with the median lethal oxygen level. Estimated median lethal levels rose slowly from fertilization to hatching. Oxygen consumption per egg rose from fertilization to hatching while the consumption per gram of larval tissue declined from a high to a low level at about the time of blastopore closure. Subsequently, a slight rise in the rate occurred up to a level which was more or less constant to hatching. "Critical" dissolved oxygen levels were calculated and they appear to define the oxygen level above which respiratory rate is unmodified by oxygen availability. Critical levels ranged from about 1 p.p.m. in early stages to over 7 p.p.m. shortly before hatching.

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Ammonia oxidation pathways and nitrifier denitrification are significant sources of N2O and NO under low oxygen availability

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1219993110 ◽

2013 ◽

Vol 110 (16) ◽

pp. 6328-6333 ◽

Cited By ~ 351

Author(s):

X. Zhu ◽

M. Burger ◽

T. A. Doane ◽

W. R. Horwath

Keyword(s):

Ammonia Oxidation ◽

Oxygen Availability ◽

Low Oxygen ◽

Nitrifier Denitrification

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Hypoxia/HIF Modulates Immune Responses

Biomedicines ◽

10.3390/biomedicines9030260 ◽

2021 ◽

Vol 9 (3) ◽

pp. 260

Author(s):

Yuling Chen ◽

Timo Gaber

Keyword(s):

Immune Response ◽

Cancer Progression ◽

Immune Cells ◽

Cell Function ◽

Immune Cell ◽

Adaptive Immune Response ◽

Oxygen Availability ◽

The Body ◽

Low Oxygen ◽

Adaptive Immune

Oxygen availability varies throughout the human body in health and disease. Under physiological conditions, oxygen availability drops from the lungs over the blood stream towards the different tissues into the cells and the mitochondrial cavities leading to physiological low oxygen conditions or physiological hypoxia in all organs including primary lymphoid organs. Moreover, immune cells travel throughout the body searching for damaged cells and foreign antigens facing a variety of oxygen levels. Consequently, physiological hypoxia impacts immune cell function finally controlling innate and adaptive immune response mainly by transcriptional regulation via hypoxia-inducible factors (HIFs). Under pathophysiological conditions such as found in inflammation, injury, infection, ischemia and cancer, severe hypoxia can alter immune cells leading to dysfunctional immune response finally leading to tissue damage, cancer progression and autoimmunity. Here we summarize the effects of physiological and pathophysiological hypoxia on innate and adaptive immune activity, we provide an overview on the control of immune response by cellular hypoxia-induced pathways with focus on the role of HIFs and discuss the opportunity to target hypoxia-sensitive pathways for the treatment of cancer and autoimmunity.

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Low oxygen levels can help to prevent the detrimental effect of acute warming on mitochondrial efficiency in fish

Biology Letters ◽

10.1098/rsbl.2020.0759 ◽

2021 ◽

Vol 17 (2) ◽

Author(s):

Elisa Thoral ◽

Damien Roussel ◽

Christos Chinopoulos ◽

Loïc Teulier ◽

Karine Salin

Keyword(s):

Dicentrarchus Labrax ◽

Acute Effect ◽

Oxygen Availability ◽

Low Oxygen ◽

Atp Production ◽

Mitochondrial Inner Membrane ◽

Highly Sensitive ◽

Environmental Variations ◽

Mitochondrial Efficiency

Aerobic metabolism of aquatic ectotherms is highly sensitive to fluctuating climates. Many mitochondrial traits exhibit phenotypic plasticity in response to acute variations in temperature and oxygen availability. These responses are critical for understanding the effects of environmental variations on aquatic ectotherms' performance. Using the European seabass, Dicentrarchus labrax , we determined the effects of acute warming and deoxygenation in vitro on mitochondrial respiratory capacities and mitochondrial efficiency to produce ATP (ATP/O ratio). We show that acute warming reduced ATP/O ratio but deoxygenation marginally raised ATP/O ratio, leading to a compensatory effect of low oxygen availability on mitochondrial ATP/O ratio at high temperature. The acute effect of warming and deoxygenation on mitochondrial efficiency might be related to the leak of protons across the mitochondrial inner membrane, as the mitochondrial respiration required to counteract the proton leak increased with warming and decreased with deoxygenation. Our study underlines the importance of integrating the combined effects of temperature and oxygen availability on mitochondrial metabolism. Predictions on decline in performance of aquatic ectotherms owing to climate change may not be accurate, since these predictions typically look at respiratory capacity and ignore efficiency of ATP production.

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