Sensitivity of Ca2+ Transport of Mitochondria to Reactive Oxygen Species

1997 ◽  
Vol 17 (6) ◽  
pp. 557-567 ◽  
Author(s):  
Zhi-wei Yang ◽  
Fu-yu Yang
Keyword(s):  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Physical State ◽  
Respiratory Control ◽  
Reactive Oxygen ◽  
Membrane Lipid ◽  
Energy Transduction ◽  
Oxygen Species ◽  
Myocardial Mitochondria ◽  
The Relationship

The relationship between Ca2+ transport and energy transduction of myocardial mitochondria in the presence of reactive oxygen species was investigated. Following treatment with oxygen free radicals [superoxide(O2•) or hydroxyl radical (•)OH], lipid free radicals in myocardial mitochondrial membrane could be detected by using the method of EPR spin trap. Simultaneously there were obvious alterations in the free Ca2+ ([Ca2+]m) in the mitochondrial matrix; the physical state of membrane lipid; the efficiency of oxidative phosphorylation (ADP/O); the value of the respiratory control ratio (RCR); and the membrane potential of the inner membrane of myocardial mitochondria. If the concentrations of reactive oxygen species were reduced by about 30%, the alterations in the physical state of the membrane lipid and energy transduction of myocardial mitochondria were not observed, but the changes in Ca2+ homeostasis remained. We conclude that Ca2+ transport by myocardial mitochondria is more sensitive to agents such as (O2•) or •OH, etc. than are oxidation phosphorylation and the respiratory chain.

scholarly journals Environmentally persistent free radicals are ubiquitous in wildfire charcoals and remain stable for years

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Gabriel Sigmund ◽  
Cristina Santín ◽  
Marc Pignitter ◽  
Nathalie Tepe ◽  
Stefan H. Doerr ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Reactive Oxygen ◽  
Resonance Spectroscopy ◽  
Oxygen Species ◽  
Pyrogenic Carbon ◽  
Spin Resonance ◽  
Long Time ◽  
High Concentrations

AbstractGlobally landscape fires produce about 256 Tg of pyrogenic carbon or charcoal each year. The role of charcoal as a source of environmentally persistent free radicals, which are precursors of potentially harmful reactive oxygen species, is poorly constrained. Here, we analyse 60 charcoal samples collected from 10 wildfires, that include crown as well as surface fires in forest, shrubland and grassland spanning different boreal, temperate, subtropical and tropical climate. Using electron spin resonance spectroscopy, we measure high concentrations of environmentally persistent free radicals in charcoal samples, much higher than those found in soils. Concentrations increased with degree of carbonization and woody fuels favoured higher concentrations. Moreover, environmentally persistent free radicals remained stable for an unexpectedly long time of at least 5 years. We suggest that wildfire charcoal is an important global source of environmentally persistent free radicals, and therefore potentially of harmful reactive oxygen species.

scholarly journals Analysis of the Relationship Between Defective Sperm Function and the Generation of Reactive Oxygen Species in Cases of Oligozoospermia

1989 ◽  
Vol 10 (3) ◽  
pp. 214-220 ◽  
Author(s):  
R. JOHN AITKEN ◽  
JANE S. CLARKSON ◽  
TIMOTHY B. HARGREAVE ◽  
D. STEWART IRVINE ◽  
FREDERICK C. W. WU
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Sperm Function ◽  
Oxygen Species ◽  
The Relationship

scholarly journals Initiation and Execution of Programmed Cell Death and Regulation of Reactive Oxygen Species in Plants

2021 ◽  
Vol 22 (23) ◽  
pp. 12942
Author(s):  
Chanjuan Ye ◽  
Shaoyan Zheng ◽  
Dagang Jiang ◽  
Jingqin Lu ◽  
Zongna Huang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Plant Stress ◽  
Reactive Oxygen ◽  
Signalling Pathways ◽  
Oxygen Species ◽  
Signalling Molecules ◽  
Plant Stress Tolerance ◽  
The Relationship

Programmed cell death (PCD) plays crucial roles in plant development and defence response. Reactive oxygen species (ROS) are produced during normal plant growth, and high ROS concentrations can change the antioxidant status of cells, leading to spontaneous cell death. In addition, ROS function as signalling molecules to improve plant stress tolerance, and they induce PCD under different conditions. This review describes the mechanisms underlying plant PCD, the key functions of mitochondria and chloroplasts in PCD, and the relationship between mitochondria and chloroplasts during PCD. Additionally, the review discusses the factors that regulate PCD. Most importantly, in this review, we summarise the sites of production of ROS and discuss the roles of ROS that not only trigger multiple signalling pathways leading to PCD but also participate in the execution of PCD, highlighting the importance of ROS in PCD.

Diagnostic Range Ionizing Radiation and Reactive Oxygen Species Production: an Initial Experience

2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Sirohi Shikha ◽  
Tandon Prof. Anupama ◽  
Banerjee Prof. B.D. ◽  
Kumar Ranjeet
Keyword(s):  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Ionizing Radiation ◽  
Venous Blood ◽  
Radiation Detection ◽  
Control Sample ◽  
Reactive Oxygen ◽  
P Value ◽  
Oxygen Species ◽  
Mdct Examination

Radiation is a common occurrence in our daily lives that comes from both natural and man-made sources. Ionizing Radiation (IR) causes damage either directly or indirectly through the generation of reactive oxygen species (ROS). Oxidative damage to DNA, lipids, proteins, and many metabolites occurs through a complex series of processes that are enhanced by endogenous signalling which is activated by free radicals. Though literature is abundant on ROS and antioxidants at high doses, no study to the best of our knowledge has assessed the ROS levels after Multi Detector Computed Tomography (MDCT) examination (i.e. in diagnostic range radiation). The aim of the present study was to assess the production of ROS after diagnostic level radiation by MDCT examination and at 24 hour follow up. The study involved fifty patients posted for clinically indicated MDCT which were recruited. The average radiation dose was 2-9 mGy. Three blood samples were drawn, one prior to CT (control sample), within half an hour of CT (post CT) and 24 hrs after CT. 3 ml venous blood was withdrawn in aseptic conditions and immediately serum was isolated for ROS assessment. The blood examination results were compared in immediate and post 24 hour after MDCT and both were compared with control values and correlated with radiation parameters. Our results have shown a significant increase in ROS level in immediate post CT samples compared to prior CT scan samples (control) (p value <0.0001). The ROS levels reduced at 24 hours compared to immediate post CT, however they were still higher than control values. Our findings reflect that there is a rapid increase in free radicals production in the mitochondria after diagnostic level radiation. Detection of higher ROS levels at 24 hours suggests incomplete repair with the presence of some residual oxidative species at 24 hours.

Extremely enhanced contaminant decomposition catalyzed by hemin via the coupling of persistent free radicals and ascorbic acid

2015 ◽  
Vol 51 (89) ◽  
pp. 16139-16142 ◽  
Author(s):  
Yuyuan Yao ◽  
Bin Jiang ◽  
Yajun Mao ◽  
Juan Chen ◽  
Zhenfu Huang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ascorbic Acid ◽  
Free Radicals ◽  
Reactive Oxygen ◽  
Environmental Pollutant ◽  
Ros Generation ◽  
Oxygen Species ◽  
Positive Role ◽  
Rate Enhancement

A positive role of PFRs in enhancing reactive oxygen species (ROS) generation for an extreme rate enhancement in environmental pollutant decomposition is reported.

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