Role of oxygen radicals in canine myocardial metabolic derangement during regional ischemia

1992 ◽  
Vol 262 (2) ◽  
pp. H553-H561 ◽  
Author(s):  
H. Ohmi ◽  
K. Ichihara ◽  
Y. Abiko

To clarify the role of oxygen radicals in the development of myocardial injury during ischemia, production of lipid peroxides mediated by oxygen radicals was determined in in vivo dogs subjected to regional ischemia and reperfusion. Myocardial injury was assessed by derangement in energy and carbohydrate metabolism caused by ischemia and reperfusion. The production of lipid peroxides mediated by oxygen radicals considerably increased not only during reperfusion after ischemia but also during ischemia. Removal of oxygen radicals by administration of radical scavengers [recombinant human superoxide dismutase + catalase or N-(2-mercaptopropionyl)glycine] completely prevented the increase in production of lipid peroxides during ischemia. However, the radical scavengers did not attenuate the myocardial energy and carbohydrate metabolic derangements caused by ischemia and reperfusion after ischemia. These results suggest that significant amounts of oxygen radicals are generated during ischemia as well as during reperfusion and that the oxygen radicals and subsequent lipid peroxidation are not major factors in development of myocardial injury during either ischemia or reperfusion after ischemia.

2003 ◽  
Vol 284 (1) ◽  
pp. H277-H282 ◽  
Author(s):  
Steven P. Jones ◽  
Michaela R. Hoffmeyer ◽  
Brent R. Sharp ◽  
Ye-Shih Ho ◽  
David J. Lefer

Reactive oxygen species induce myocardial damage after ischemia and reperfusion in experimental animal models. Numerous studies have investigated the deleterious effects of ischemia-reperfusion (I/R)-induced oxidant production using various pharmacological interventions. More recently, in vitro studies have incorporated gene-targeted mice to decipher the role of antioxidant enzymes in myocardial reperfusion injury. We examined the role of cellular antioxidant enzymes in the pathogenesis of myocardial I/R (MI/R) injury in vivo in gene-targeted mice. Neither deficiency nor overexpression of Cu-Zn superoxide dismutase (SOD) altered the extent of myocardial necrosis. Overexpression of glutathione peroxidase did not affect the degree of myocardial injury. Conversely, overexpression of manganese (Mn)SOD significantly attenuated myocardial necrosis after MI/R. Transthoracic echocardiography was performed on MnSOD-overexpressing and wild-type mice that were subjected to a more prolonged period of reperfusion. Cardiac output was significantly depressed in the nontransgenic but not the transgenic MnSOD-treated mice. Anterior wall motion was significantly impaired in the nontransgenic mice. These findings demonstrate an important role for MnSOD but not Cu/ZnSOD or glutathione peroxidase in mice after in vivo MI/R.


2006 ◽  
Vol 84 (8-9) ◽  
pp. 903-912 ◽  
Author(s):  
Sarah J. Canyon ◽  
Geoffrey P. Dobson

We have previously shown that an intravenous infusion of adenosine and lidocaine (AL) solution protects against death and severe arrhythmias and reduces infarct size in the in vivo rat model of regional ischemia. The aim of this study was to examine the relative changes of myocardial high-energy phosphates (ATP and PCr) and pH in the left ventricle during ischemia–reperfusion using 31P NMR in AL-treated rats (n = 7) and controls (n = 6). The AL solution (A: 305 μg·(kg body mass)–1·min–1; L: 608 μg·(kg body mass)–1·min–1) was administered intravenously 5 min before and during 30 min coronary artery ligation. Two controls died from ventricular fibrillation; no deaths were recorded in AL-treated rats. In controls that survived, ATP fell to 73% ± 29% of baseline by 30 min ischemia and decreased further to 68% ± 28% during reperfusion followed by a sharp recovery at the end of the reperfusion period. AL-treated rats maintained relatively constant ATP throughout ischemia and reperfusion ranging from 95% ± 6% to 121% ± 10% of baseline. Owing to increased variability in controls, these results were not found to be significant. In contrast, control [PCr] was significantly reduced in controls compared with AL-treated rats during ischemia at 10 min (68% ± 7% vs. 99% ± 6%), at 15 min (68% ± 10% vs. 93% ± 2%), and at 20 min (67% ± 15% vs. 103% ± 5%) and during reperfusion at 10 min (56% ± 22% vs. 99% ± 7%), at 15 min (60% ± 10% vs. 98% ± 7%), and at 35 min (63% ± 14% vs. 120% ± 11%) (p < 0.05). Interestingly, changes in intramyocardial pH between each group were not significantly different during ischemia and fell by about 1 pH unit to 6.6. During reperfusion, pH in AL-treated rats recovered to baseline in 5 min but not in controls, which recovered to only around pH 7.1. There was no significant difference in the heart rate, mean arterial pressure, and rate-pressure product between the controls and AL treatment during ischemia and reperfusion. We conclude that AL cardioprotection appears to be associated with the preservation of myocardial high-energy phosphates, downregulation of the heart at the expense of a high acid-load during ischemia, and with a rapid recovery of myocardial pH during reperfusion.


2015 ◽  
Vol 36 (4) ◽  
pp. 1628-1643 ◽  
Author(s):  
Yingqi Xu ◽  
Wenliang Zhu ◽  
Yong Sun ◽  
Zhe Wang ◽  
Wei Yuan ◽  
...  

Background: Acting on many mRNAs allows the power of a single miRNA to modulate multiple pathophysiological phenotypes. One question is whether versatile miRNAs exist in the pathological scenarios of myocardial infarction (MI) and heart failure (HF). Methods: A hypergeometric analysis, in combination with network-based functional analyses, was performed on the available human protein interaction and miRNA-gene association data to highlight versatile miRNAs among the significantly dysregulated miRNAs in MI and HF. In vivo, mice models of MI and HF were then established to investigate whether dysregulated expression be undertaken by versatile miRNA identified here. Results: Systematic analyses really identified the previously validated miRNAs that have been verified of multiple important roles in MI and HF, demonstrating method effectiveness. By using this means, we innovatively revealed the vital role of miR-7 in maintaining the dynamic balance of protein interactions and its obvious overexpression in MI and HF that implies pathological involvement. Functional experiments are definitely needed for further revealing its potential influences on MI- or HF-led myocardial injury. Conclusion: Our results have implications not only for the coming miRNA-based strategy in treating MI and HF but also for further understanding on gene regulation by miRNAs in human heart.


1986 ◽  
Vol 18 ◽  
pp. 68-68
Author(s):  
W VANGILST ◽  
P DEGRAEFF ◽  
J KINGMA ◽  
C DELANGEN ◽  
H WESSELING

1996 ◽  
Vol 16 (1) ◽  
pp. 175-179 ◽  
Author(s):  
Wei Meng ◽  
David W. Busija

This study examined the role of oxygen radicals in pial arteriolar changes during cortical spreading depression (CSD). CSD was induced by microinjection of 5% KCl in anesthetized adult rabbits. Pial diameter was measured with a closed cranial window and intravital microscopy. During control CSD (n = 12), the dilation amplitude and area were 55 ± 14% and 693 ± 69 mm2 (baseline = 76 ± 14 μm), respectively. Oxygen radical scavengers, superoxide dismutase (SOD; 105 U/ml, topical application; n = 5) or oxypurinol (50 mg/kg i.v.; n = 7), did not alter the dilation amplitude and area or change onset latency during CSD. Further, SOD and oxypurinol did not prevent NG-nitro-L-arginine from attenuating arteriolar dilation during CSD (n = 12). We conclude that oxygen radicals do not play a role in the transient dilation of cerebral arterioles during CSD.


Author(s):  
Doreen Lau ◽  
Laura M. Lechermann ◽  
Ferdia A. Gallagher

AbstractNeutrophils are the first line of defense against pathogens and abnormal cells. They regulate many biological processes such as infections and inflammation. Increasing evidence demonstrated a role for neutrophils in cancer, where different subpopulations have been found to possess both pro- or anti-tumorigenic functions in the tumor microenvironment. In this review, we discuss the phenotypic and functional diversity of neutrophils in cancer, their prognostic significance, and therapeutic relevance in human and preclinical models. Molecular imaging methods are increasingly used to probe neutrophil biology in vivo, as well as the cellular changes that occur during tumor progression and over the course of treatment. This review will discuss the role of neutrophil imaging in oncology and the lessons that can be drawn from imaging in infectious diseases and inflammatory disorders. The major factors to be considered when developing imaging techniques and biomarkers for neutrophils in cancer are reviewed. Finally, the potential clinical applications and the limitations of each method are discussed, as well as the challenges for future clinical translation.


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