Search results for "Peroxides"
showing 10 items of 162 documents
Effect of xanthine oxidase-generated extracellular superoxide on skeletal muscle force generation
2009
Skeletal muscle contractions increase superoxide anion in skeletal muscle extracellular space. We tested the hypotheses that 1) after an isometric contraction protocol, xanthine oxidase (XO) activity is a source of superoxide anion in the extracellular space of skeletal muscle and 2) the increase in XO-derived extracellular superoxide anion during contractions affects skeletal muscle contractile function. Superoxide anion was monitored in the extracellular space of mouse gastrocnemius muscles by following the reduction of cytochrome c in muscle microdialysates. A 15-min protocol of nondamaging isometric contractions increased the reduction of cytochrome c in microdialysates, indicating an …
Cadmium-Induced Enteropathy in Domestic Cocks: A Biochemical and Histological Study after Subchronic Exposure
2007
The biochemical and histological sequelae resulting from a diet containing 50.20 mg cadmium/kg were studied in Lohmann brown cockerels from hatching until 30 days of age. The additional cadmium chloride (CdCl(2)) to the diet induced the formation of lipid peroxides, which via a chain reaction led to accumulation of malondialdehyde in intestinal mucosa. At the end of the study (after 30 days of cadmium exposure) total protein and metallothionein levels in the intestinal mucosa and the relative ileal and duodenal weight increased. Histological data show that CdCl(2) causes an increase in number of goblet cells and granular lymphocytes in the intestinal mucosa. Down-regulation of the serotonin…
Mitochondria from females exhibit higher antioxidant gene expression and lower oxidative damage than males
2003
We have investigated the differential mitochondrial oxidative stress between males and females to understand the molecular mechanisms enabling females to live longer than males. Mitochondria are a major source of free radicals in cells. Those from female rats generate half the amount of peroxides than those of males. This does not occur in ovariectomized animals. Estrogen replacement therapy prevents the effect of ovariectomy. Mitochondria from females have higher levels of reduced glutathione than those from males. Those from ovariectomized rats have similar levels to males, and estrogen therapy prevents the fall in glutathione levels that occurs in ovariectomized animals. Oxidative damage…
Ursodeoxycholic acid protects against secondary biliary cirrhosis in rats by preventing mitochondrial oxidative stress
2004
Ursodeoxycholic acid (UDCA) improves clinical and biochemical indices in primary biliary cirrhosis and prolongs survival free of liver transplantation. Recently, it was suggested that the cytoprotective mechanisms of UDCA may be mediated by protection against oxidative stress, which is involved in the development of cirrhosis induced by chronic cholestasis. The aims of the current study were 1) to identify the mechanisms involved in glutathione depletion, oxidative stress, and mitochondrial impairment during biliary cirrhosis induced by chronic cholestasis in rats; and 2) to determine the mechanisms associated with the protective effects of UDCA against secondary biliary cirrhosis. The find…
REDUCED OXIDATIVE STRESS DURING ACELLULAR REPERFUSION OF THE RAT LIVER AFTER HYPOTHERMIC OSCILLATING PERFUSION
1999
Background ATP resynthesis during reperfusion after liver preservation has been shown to be well correlated with the function of transplanted grafts. Nevertheless, the advantages of a cellular energy charge loading during the preservation period are yet not fully understood. This study evaluates the effects of different nucleotide levels at the end of preservation on metabolic changes and oxidative stress during reperfusion. Methods Two experimental groups were chosen reflecting different energy charge states after preservation: static cold storage for 10 hr and hypothermic oxygenated oscillating perfusion for 10 hr. In both experimental groups, normothermic ex vivo acellular reperfusion ov…
Oxidant/antioxidant status in obese children compared to pediatric patients with type 1 diabetes mellitus.
2009
Codoner-Franch P, Pons-Morales S, Boix-Garcia L, Valls-Belles V. Oxidant/antioxidant status in obese children compared to pediatric patients with type 1 diabetes mellitus. Background: Type 1 diabetes (T1D) mellitus and obesity are recognized risk factors for cardiovascular disease (CVD). A common mechanism underlying an increased risk for endothelial dysfunction in these two metabolic diseases is oxidative stress. Objective: To evaluate and compare the oxidant/antioxidant defense systems in children affected with T1D or obesity in order to determine the importance of oxidative stress before the emergence of complications. Subjects: Children with T1D (n = 20) or obesity (n = 22), without com…
Absence of lipid peroxidation as determined by ethane exhalation in rats treated with 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD).
1985
The exhalation of ethane is widely used as an indicator of in vivo lipid peroxidation. To test the hypothesis that lipid peroxidative events are involved in the toxicity of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), we administered a lethal dose of TCDD (60 μg/kg), IP to male Sprague Dawley rats (160–180 g) and measured by gas chromatography the exhalation of ethane into the atmosphere of a closed all-glass exposure chamber. TCDD-treated rats exhaled only slightly more ethane than control rats at a single time point 7 days following TCDD administration. Since the exhalation of ethane is the net result of the endogenous production of the gas and its metabolic degradation, the latter was …
Pregnenolone sulfate, a naturally occurring excitotoxin involved in delayed retinal cell death.
2002
The present study was designed to investigate the neurosteroid pregnenolone sulfate (PS), known for its ability to modulate NMDA receptors and interfere with acute excitotoxicity, in delayed retinal cell death. Three hours after exposure of the isolated and intact retina to a 30-min PS pulse, DNA fragmentation as assessed by genomic DNA gel electrophoresis and a modified in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method appeared concurrently with an increase in superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) levels. At 7 h, the increased amount of DNA laddering was accompanied by a higher number of TUN…
Chronic Therapy With Isosorbide-5-Mononitrate Causes Endothelial Dysfunction, Oxidative Stress and a Marked Increase in Vascular Endothelin-1 Express…
2011
Aims Isosorbide-5-mononitrate (ISMN) is one of the most frequently used compounds in the treatment of coronary artery disease predominantly in the USA. However, ISMN was reported to induce endothelial dysfunction, which was corrected by vitamin C pointing to a crucial role of reactive oxygen species (ROS) in causing this phenomenon. We sought to elucidate the mechanism how ISMN causes endothelial dysfunction and oxidative stress in vascular tissue. Methods and results Male Wistar rats ( n = 69 in total) were treated with ISMN (75 mg/kg/day) or placebo for 7 days. Endothelin (ET) expression was determined by immunohistochemistry in aortic sections. Isosorbide-5-mononitrate infusion caused si…
Resveratrol Reverses Endothelial Nitric-Oxide Synthase Uncoupling in Apolipoprotein E Knockout Mice
2010
A crucial cause of the decreased bioactivity of nitric oxide (NO) in cardiovascular diseases is the uncoupling of the endothelial NO synthase (eNOS) caused by the oxidative stress-mediated deficiency of the NOS cofactor tetrahydrobiopterin (BH(4)). The reversal of eNOS uncoupling might represent a novel therapeutic approach. The treatment of apolipoprotein E knockout (ApoE-KO) mice with resveratrol resulted in the up-regulation of superoxide dismutase (SOD) isoforms (SOD1-SOD3), glutathione peroxidase 1 (GPx1), and catalase and the down-regulation of NADPH oxidases NOX2 and NOX4 in the hearts of ApoE-KO mice. This was associated with reductions in superoxide, 3-nitrotyrosine, and malondiald…