Elevated ROS depress mitochondrial oxygen utilization efficiency in cardiomyocytes during acute hypoxia

AbstractRapid adaptation to a hypoxic environment is an unanswered question that we are committed to exploring. At present, there is no suitable strategy to achieve rapid hypoxic adaptation. Here, we demonstrate that fasting preconditioning for 72 h reduces tissue injuries and maintains cardiac function, consequently significantly improving the survival rates of rats under extreme hypoxia, and this strategy can be used for rapid hypoxic adaptation. Mechanistically, fasting reduces blood glucose and further suppresses tissue mTOR activity. On the one hand, fasting-induced mTOR inhibition reduces unnecessary ATP consumption and increases ATP reserves under acute hypoxia as a result of decreased protein synthesis and lipogenesis; on the other hand, fasting-induced mTOR inhibition improves mitochondrial oxygen utilization efficiency to ensure ATP production under acute hypoxia, which is due to the significant decrease in ROS generation induced by enhanced mitophagy. Our findings highlight the important role of mTOR in acute hypoxic adaptation, and targeted regulation of mTOR could be a new strategy to improve acute hypoxic tolerance in the body.

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Improved Oxygen Dissolution Control for Oxygen Activated Sludge

Water Science & Technology ◽

10.2166/wst.1988.0158 ◽

1988 ◽

Vol 20 (4-5) ◽

pp. 101-108 ◽

Cited By ~ 2

Author(s):

R. C. Clifft ◽

M. T. Garrett

Keyword(s):

Activated Sludge ◽

Control Method ◽

Control Strategies ◽

Cost Savings ◽

Utilization Efficiency ◽

Oxygen Production ◽

Oxygen Utilization ◽

Potential Cost ◽

Oxygen Dissolution ◽

The City

Now that oxygen production facilities can be controlled to match the requirements of the dissolution system, improved oxygen dissolution control can result in significant cost savings for oxygen activated sludge plants. This paper examines the potential cost savings of the vacuum exhaust control (VEC) strategy for the City of Houston, Texas 69th Street Treatment Complex. The VEC strategy involves operating a closed-tank reactor slightly below atmospheric pressure and using an exhaust apparatus to remove gas from the last stage of the reactor. Computer simulations for one carbonaceous reactor at the 69th Street Complex are presented for the VEC and conventional control strategies. At 80% of design loading the VEC strategy was found to provide an oxygen utilization efficiency of 94.9% as compared to 77.0% for the conventional control method. At design capacity the oxygen utilization efficiency for VEC and conventional control was found to be 92.3% and 79.5%, respectively. Based on the expected turn-down capability of Houston's oxygen production faciilities, the simulations indicate that the VEC strategy will more than double the possible cost savings of the conventional control method.

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Improved exercise capacity in cyclophilin‐D knockout mice associated with enhanced oxygen utilization efficiency and augmented glucose uptake via AMPK‐TBC1D1 signaling nexus

The FASEB Journal ◽

10.1096/fj.201802238r ◽

2019 ◽

Vol 33 (10) ◽

pp. 11443-11457 ◽

Cited By ~ 2

Author(s):

Jeejabai Radhakrishnan ◽

Alvin Baetiong ◽

Harrison Kaufman ◽

Michelle Huynh ◽

Angela Leschinsky ◽

...

Keyword(s):

Glucose Uptake ◽

Exercise Capacity ◽

Knockout Mice ◽

Utilization Efficiency ◽

Cyclophilin D ◽

Oxygen Utilization

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Left ventricular oxygen utilization efficiency is impaired in chronic streptozotocin-diabetic sheep

Cardiovascular Research ◽

10.1016/s0008-6363(02)00497-2 ◽

2002 ◽

Vol 55 (4) ◽

pp. 749-756 ◽

Cited By ~ 9

Author(s):

T Ramanathan

Keyword(s):

Left Ventricular ◽

Utilization Efficiency ◽

Oxygen Utilization

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Long-Term Adaptation of Cerebral Hemodynamic Response to Somatosensory Stimulation during Chronic Hypoxia in Awake Mice

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2013.16 ◽

2013 ◽

Vol 33 (5) ◽

pp. 774-779 ◽

Cited By ~ 21

Author(s):

Hiroyuki Takuwa ◽

Kazuto Masamoto ◽

Kyoko Yamazaki ◽

Hiroshi Kawaguchi ◽

Yoko Ikoma ◽

...

Keyword(s):

Energy Demand ◽

Chronic Hypoxia ◽

Acute Hypoxia ◽

Effective Diffusivity ◽

Sensory Stimulation ◽

Hemodynamic Response ◽

Neural Activation ◽

Oxygen Utilization ◽

Somatosensory Stimulation ◽

Doppler Flowmetry

Effects of chronic hypoxia on hemodynamic response to sensory stimulation were investigated. Using laser-Doppler flowmetry, change in cerebral blood flow ( CBF) was measured in awake mice, which were housed in a hypoxic chamber (8% O2) for 1 month. The degree of increase in CBF evoked by sensory stimulation was gradually decreased over 1 month of chronic hypoxia. No significant reduction of increase in CBF induced by hypercapnia was observed during 1 month. Voltage-sensitive dye (VSD) imaging of the somatosensory cortex showed no significant decrease in neural activation over 1 month, indicating that the reduction of increase in CBF to sensory stimulation was not caused by cerebrovascular or neural dysfunction. The simulation study showed that, when effective diffusivity for oxygen in the capillary bed ( D) value increases by chronic hypoxia due to an increase in capillary blood volume, an increase in the cerebral metabolic rate of oxygen utilization during neural activation can occur without any increase in CBF. Although previous study showed no direct effects of acute hypoxia on CBF response, our finding showed that hemodynamic response to neural activation could be modified in response to a change in their balance to energy demand using chronic hypoxia experiments.

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