Reactive oxygen species generated during myocardial ischemia enable energetic recovery during reperfusion

2002 ◽  
Vol 283 (4) ◽  
pp. H1656-H1661 ◽  
Author(s):  
Paul F. Klawitter ◽  
Holt N. Murray ◽  
Thomas L. Clanton ◽  
Mark G. Angelos
Keyword(s):  
Reactive Oxygen Species ◽  
Myocardial Ischemia ◽  
Reactive Oxygen ◽  
High Energy ◽  
High Energy Phosphates ◽  
Oxygen Species ◽  
Sprague Dawley ◽  
Additional Group ◽  
Rat Hearts ◽  
Superoxide Scavenger

We studied the differences between the functional and bioenergetic effects of antioxidants (AOX) administered before or after myocardial ischemia. Sprague-Dawley rat hearts were perfused with a modified Krebs-Henseleit solution and bubbled with 95% O2-5% CO2. The protocol consisted of 10 min of baseline perfusion, 20 min of global ischemia, and 30 min of reperfusion. An AOX, either 1,2-dihydroxybenzene-3,5-disulfonate (Tiron), a superoxide scavenger, or N-acetyl-l-cysteine, was infused during either baseline or reperfusion. An additional group received deferoxamine as a bolus before ischemia. Hearts were freeze-clamped at baseline, at end of ischemia, and at end of reperfusion for analysis of high-energy phosphates. All AOX, when given before ischemia, inhibited recovery of ATP compared with controls. Both Tiron and deferoxamine also inhibited recovery of phosphocreatine. AOX given before ischemia decreased the efficiency of contraction during reperfusion compared with controls. All of the changes in energetics and efficiency brought on by preischemic AOX treatment could be blocked by a preconditioning stimulus. This suggests that reactive oxygen species, which are generated during ischemia, enhance bioenergetic recovery by increasing the efficiency of contraction.

scholarly journals Molecular Characterization of Reactive Oxygen Species in Myocardial Ischemia-Reperfusion Injury

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tingyang Zhou ◽  
Chia-Chen Chuang ◽  
Li Zuo
Keyword(s):  
Reactive Oxygen Species ◽  
Myocardial Ischemia ◽  
Energy Demand ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
High Energy ◽  
Protective Mechanism ◽  
Oxygen Species ◽  
Myocardial Ischemia Reperfusion

Myocardial ischemia-reperfusion (I/R) injury is experienced by individuals suffering from cardiovascular diseases such as coronary heart diseases and subsequently undergoing reperfusion treatments in order to manage the conditions. The occlusion of blood flow to the tissue, termed ischemia, can be especially detrimental to the heart due to its high energy demand. Several cellular alterations have been observed upon the onset of ischemia. The danger created by cardiac ischemia is somewhat paradoxical in that a return of blood to the tissue can result in further damage. Reactive oxygen species (ROS) have been studied intensively to reveal their role in myocardial I/R injury. Under normal conditions, ROS function as a mediator in many cell signaling pathways. However, stressful environments significantly induce the generation of ROS which causes the level to exceed body’s antioxidant defense system. Such altered redox homeostasis is implicated in myocardial I/R injury. Despite the detrimental effects from ROS, low levels of ROS have been shown to exert a protective effect in the ischemic preconditioning. In this review, we will summarize the detrimental role of ROS in myocardial I/R injury, the protective mechanism induced by ROS, and potential treatments for ROS-related myocardial injury.

scholarly journals Efek Ekstrak Etanol Daun Gedi Merah (Abelmoschus Manihot (L.) Medik) Terhadap Kadar Superoxide Dismutase Dan Malondialdehyde Jaringan Ginjal Tikus Model Diabetes Melitus Tipe 2

2020 ◽  
Vol 8 (2) ◽  
pp. 83
Author(s):  
Ahmad Fuadi ◽  
Yoyon Arif ◽  
Yudi Purnomo
Keyword(s):  
Reactive Oxygen Species ◽  
Superoxide Dismutase ◽  
Multiple Dose ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Sprague Dawley ◽  
Per Oral ◽  
One Way Anova ◽  
Diabetes Melitus

Hiperglikemia pada Diabetes Melitus (DM) meningkatkan produksi Reactive Oxygen Species (ROS) dan berperan terhadap risiko komplikasi nefropati diabetik. Daun gedi merah (Abelmoschus manihot (L.) Medik) berkhasiat sebagai antidiabetik dan antioksidan tetapi penelitian ekstrak etanol daun gedi merah (EEDGM) untuk mencegah nefropati diabetik belum banyak dilaporkan. Penelitian ini bertujuan untuk mengetahui efek EEDGM terhadap kadar SOD dan MDA ginjal tikus model DM.Metode: Tikus Sprague dawley jantan usia 4-6 minggu dikelompokan menjadi 2 kelompok kontrol dan 3 kelompok perlakuan (n=25 ekor). Tikus DM dibuat dengan diet tinggi lemak-fruktosa (DTLF) dan streptozotocin (STZ) 25 mg/kgBB i.p multiple dose. Ekstrak etanol daun gedi merah (EEDGM) diberikan per oral selama 4 minggu. Kadar SOD dan MDA ginjal diukur menggunakan SOD rat kit dan MDA rat kit. Hasil dianalisa dengan One Way Anova dilanjutkan dengan uji BNT (p<0,05).Hasil: Pemberian EEDGM dosis 800 mg/kgBB menghambat penurunan kadar SOD jaringan ginjal dengan persentase sekitar 60% dibandingkan KDM (p<0,05). Pemberian EEDGM dosis 400 mg/kgBB menghambat peningkatan kadar MDA jaringan ginjal dengan persentase sekitar 20% dibandingkan KDM (p<0,05). Induksi DTLF dan STZ menurunkan kadar SOD jaringan ginjal dengan persentase sekitar 40% dan meningkatkan kadar MDA jaringan ginjal dengan persentase sekitar 30%.Kesimpulan: Pemberian EEDGM dapat menghambat penurunan kadar SOD dan peningkatan kadar MDA jaringan ginjal tikus model DM.

scholarly journals PGC-1α, Inflammation, and Oxidative Stress: An Integrative View in Metabolism

2020 ◽  
Vol 2020 ◽  
pp. 1-20 ◽  
Author(s):  
Sergio Rius-Pérez ◽  
Isabel Torres-Cuevas ◽  
Iván Millán ◽  
Ángel L. Ortega ◽  
Salvador Pérez
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Metabolic Syndrome ◽  
Inflammatory Response ◽  
Reactive Oxygen ◽  
High Energy ◽  
Low Grade ◽  
Oxygen Species ◽  
Antioxidant Genes ◽  
Integrative View

Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α is a transcriptional coactivator described as a master regulator of mitochondrial biogenesis and function, including oxidative phosphorylation and reactive oxygen species detoxification. PGC-1α is highly expressed in tissues with high energy demands, and it is clearly associated with the pathogenesis of metabolic syndrome and its principal complications including obesity, type 2 diabetes mellitus, cardiovascular disease, and hepatic steatosis. We herein review the molecular pathways regulated by PGC-1α, which connect oxidative stress and mitochondrial metabolism with inflammatory response and metabolic syndrome. PGC-1α regulates the expression of mitochondrial antioxidant genes, including manganese superoxide dismutase, catalase, peroxiredoxin 3 and 5, uncoupling protein 2, thioredoxin 2, and thioredoxin reductase and thus prevents oxidative injury and mitochondrial dysfunction. Dysregulation of PGC-1α alters redox homeostasis in cells and exacerbates inflammatory response, which is commonly accompanied by metabolic disturbances. During inflammation, low levels of PGC-1α downregulate mitochondrial antioxidant gene expression, induce oxidative stress, and promote nuclear factor kappa B activation. In metabolic syndrome, which is characterized by a chronic low grade of inflammation, PGC-1α dysregulation modifies the metabolic properties of tissues by altering mitochondrial function and promoting reactive oxygen species accumulation. In conclusion, PGC-1α acts as an essential node connecting metabolic regulation, redox control, and inflammatory pathways, and it is an interesting therapeutic target that may have significant benefits for a number of metabolic diseases.

scholarly journals Role of TNF-α-induced reactive oxygen species in endothelial dysfunction during reperfusion injury

2008 ◽  
Vol 295 (6) ◽  
pp. H2242-H2249 ◽  
Author(s):  
Xue Gao ◽  
Hanrui Zhang ◽  
Souad Belmadani ◽  
Junxi Wu ◽  
Xiangbin Xu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Dysfunction ◽  
Myocardial Ischemia ◽  
Endothelial Function ◽  
Xanthine Oxidase ◽  
Reactive Oxygen ◽  
Neutrophil Activation ◽  
Superoxide Production ◽  
Oxygen Species ◽  
Tnf Α

We hypothesized that neutralization of TNF-α at the time of reperfusion exerts a salubrious role on endothelial function and reduces the production of reactive oxygen species. We employed a mouse model of myocardial ischemia-reperfusion (I/R, 30 min/90 min) and administered TNF-α neutralizing antibodies at the time of reperfusion. I/R elevated TNF-α expression (mRNA and protein), whereas administration of anti-TNF-α before reperfusion attenuated TNF-α expression. We detected TNF-α expression in vascular smooth muscle cells, mast cells, and macrophages, but not in the endothelial cells. I/R induced endothelial dysfunction and superoxide production. Administration of anti-TNF-α at the onset of reperfusion partially restored nitric oxide-mediated coronary arteriolar dilation and reduced superoxide production. I/R increased the activity of NAD(P)H oxidase and of xanthine oxidase and enhanced the formation of nitrotyrosine residues in untreated mice compared with shams. Administration of anti-TNF-α before reperfusion blocked the increase in activity of these enzymes. Inhibition of xanthine oxidase (allopurinol) or NAD(P)H oxidase (apocynin) improved endothelium-dependent dilation and reduced superoxide production in isolated coronary arterioles following I/R. Interestingly, I/R enhanced superoxide generation and reduced endothelial function in neutropenic animals and in mice treated with a neutrophil NAD(P)H oxidase inhibitor, indicating that the effects of TNF-α are not through neutrophil activation. We conclude that myocardial ischemia initiates TNF-α expression, which induces vascular oxidative stress, independent of neutrophil activation, and leads to coronary endothelial dysfunction.

Antioxidant effect of pomegranate extract in reducing acute inflammation due to myringotomy

2011 ◽  
Vol 125 (4) ◽  
pp. 370-375 ◽  
Author(s):  
V Kahya ◽  
A Meric ◽  
M Yazici ◽  
M Yuksel ◽  
A Midi ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Acute Inflammation ◽  
Histological Study ◽  
Reactive Oxygen ◽  
Inflammatory Cells ◽  
Oxygen Species ◽  
Sprague Dawley ◽  
Randomised Study ◽  
Sprague Dawley Rats ◽  
Reactive Oxygen Species Concentration

AbstractObjective:To assess the effect of pomegranate extract on acute inflammation due to myringotomy.Design:Prospective, randomised study.Subjects:Thirty Sprague–Dawley rats were divided into three groups. Group one constituted controls. Group two underwent myringotomy. Group three underwent myringotomy and also received 100 µl/day pomegranate extract, via gavage, one day before and two days after surgery. Following sacrifice 48 hours after myringotomy, the animals' right ears were used to determine the concentration of reactive oxygen species, using the chemiluminescence method; left ears were used for histological study.Results:Reactive oxygen species levels were significantly decreased in group three compared with group two (p < 0.01). The density of inflammatory cells in group three was significantly less than that in group two (p < 0.01). Lamina propria thickness and vessel density were also significantly decreased in group three compared with group two (p < 0.01).Conclusion:Our results indicate that oral pomegranate extract decreases reactive oxygen species concentration and acute inflammation in the tympanic membrane after myringotomy.

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