Search results for "peroxidation"
showing 10 items of 308 documents
Role of oxygen and nitrogen species in experimental uveitis: anti-inflammatory activity of the synthetic antioxidant ebselen.
2002
This study was aimed at examining the role of oxygen and nitrogen reactive species in a model of experimental uveitis upon intravitreal injection of bacterial endotoxin to albino New Zealand rabbits. The inflammatory response was evaluated in terms of: (i) the integrity of the blood aqueous barrier (protein and cell content in samples of aqueous humor), (ii) histopathological changes of the eyes, (iii) clinical evaluation (with a score index based on clinical symptoms), and (iv) the concentration of malondialdehyde (MDA), in aqueous humor, as a marker of oxidative stress. Betamethasone was used as reference treatment, superoxide dismutase as quencher of superoxide anion, L-N(G)-nitro-L-argi…
Short-term e-cigarette vapour exposure causes vascular oxidative stress and dysfunction: evidence for a close connection to brain damage and a key ro…
2019
Abstract Aims Electronic (e)-cigarettes have been marketed as a ‘healthy’ alternative to traditional combustible cigarettes and as an effective method of smoking cessation. There are, however, a paucity of data to support these claims. In fact, e-cigarettes are implicated in endothelial dysfunction and oxidative stress in the vasculature and the lungs. The mechanisms underlying these side effects remain unclear. Here, we investigated the effects of e-cigarette vapour on vascular function in smokers and experimental animals to determine the underlying mechanisms. Methods and results Acute e-cigarette smoking produced a marked impairment of endothelial function in chronic smokers determined b…
Even free radicals should follow some rules: a guide to free radical research terminology and methodology.
2014
Free radicals and oxidants are now implicated in physiological responses and in several diseases. Given the wide range of expertise of free radical researchers, application of the greater understanding of chemistry has not been uniformly applied to biological studies. We suggest that some widely used methodologies and terminologies hamper progress and need to be addressed. We make the case for abandonment and judicious use of several methods and terms and suggest practical and viable alternatives. These changes are suggested in four areas: use of fluorescent dyes to identify and quantify reactive species, methods for measurement of lipid peroxidation in complex biological systems, claims of…
The effects of alpha-cypermethrin exposure on biochemical and redox parameters in pregnant rats and their newborns
2016
IF 2.388; International audience; Pyrethroid insecticides are extensively used in agriculture and in household activities. During pregnancy, they might affect maternal metabolic status and there after fetal development. In this work, we studied metabolic and redox effects of low dose alpha-cypermethrin exposure in pregnant rats and their offspring. The diet containing alpha cypermethrin at 0.02 mg/kg/day was consumed during the entire gestation. Plasma biochemical parameters as well as liver lipid and oxidative stress markers were determined. Our results showed that alpha-cypermethrin induced an increase in body weight and in plasma glucose and lipid levels, as well as in plasma aspartate a…
Antioxidant treatment for impaired hypoxic ventilatory responses in experimental diabetes in the rat
2018
Inflammation, tissue hypoxia, and impaired hypoxic ventilatory response (HVR) are the intricately entwined features of diabetes which perpetuate the disease and its sequelae. Hyperglycemia, notably, is an oxygen consuming process due to enhanced cellular metabolism. Oxidative stress underlies diabetic pathogenesis and also is a crucial modulator of the hypoxic chemoreflex. The present study seeks to determine if suppressed ventilation in diabetes could be improved by antioxidant treatment. The study was performed in streptozotocin-induced diabetes in awake rats. Two weeks into full-fledged diabetes, the rats were divided into mangiferin (potent natural antioxidant)-treated and untreated, wi…
POSTPRANDIAL HYPERGLYCEMIA IS A DETERMINANT OF PLATELET ACTIVATION IN EARLY 2 DIABETES MELLITUS
2010
BACKGROUND: Chronic hyperglycemia is a major contributor to in vivo platelet activation in diabetes mellitus. OBJECTIVES: To evaluate the effects of acarbose, an alpha-glucosidase inhibitor, on platelet activation and its determinants in newly diagnosed type 2 diabetic patients. METHODS: Forty-eight subjects (26 males, aged 61 +/- 8 years) with early type 2 diabetes (baseline hemoglobin A(1c) < or = 7% and no previous hypoglycemic treatment) were randomly assigned to acarbose up to 100 mg three times a day or placebo, and evaluated every 4 weeks for 20 weeks. The main outcome measures were urinary 11-dehydro-thromboxane (TX)B(2) (marker of in vivo platelet activation) and 8-iso-prostaglandi…
Antioxidant effect of Ajuga iva aqueous extract in streptozotocin-induced diabetic rats.
2009
The purpose of this study was to investigate the possible antioxidant effect of an aqueous extract of Ajuga iva (Ai) in streptozotocin (STZ)-induced diabetic rats. Twelve diabetic rats were divided into two groups fed a casein diet supplemented or not with Ai (0.5%), for 4 weeks. In vitro, the Ai extract possessed a very high antioxidant effect (1 mg/ml was similar to those of trolox 300 mmol/l). The results indicated that plasma thiobarbituric acid reactive substances (TBARS) values were reduced by 41% in Ai-treated compared with untreated diabetic rats. TBARS concentrations were lower 1.5-fold in liver, 1.8-fold in heart, 1.9-fold in muscle and 2.1-fold in brain in Ai-treated than untreat…
Fructose-enriched diet modifies antioxidant status and lipid metabolism in spontaneously hypertensive rats
2005
Abstract Objective High-fructose consumption in industrial countries has been shown to induce metabolic abnormalities or syndrome X. Changes in antioxidant defense are unknown in hypertension associated with metabolic disorders induced by high-fructose feeding. Methods Twenty spontaneously hypertensive rats were assigned to one of two groups; one received a fructose-enriched diet (60% fructose) and the other a starch diet. After a 13-wk diet period, total antioxidant status was assessed in the blood and liver by monitoring the rate of free radical-induced red blood cell hemolysis. Antioxidants (enzymes and vitamins) were determined in blood and liver. Gene expression of antioxidant enzymes …
Oxidant stress: the role of nutrients in cell-lipoprotein interactions
1999
Oxidant stress is increasingly becoming an important hypothesis to explain the genesis of several pathologies, including cancer, atherosclerosis and also ageing. Beside a few rare genetic defects, dietary factors are thought to play a key role in the regulation of the production of reactive oxygenated species. An imbalance between nutrients, and in particular those involved in antioxidant status, could explain the onset of an enhanced production of free radicals. We will briefly review information concerning oxidation of lipids and lipoproteins which lead to atherothrombosis. We also present new findings supporting a role for blood platelets in generating oxidant species. New data are also …
Enhanced platelet thromboxane synthesis and reduced macrophage-dependent fibrinolytic activity related to oxidative stress in oral contraceptive-trea…
1996
Abstract In previous studies conducted in rats and in women, we have shown that oral contraceptive (OC) administration induced a platelet hyperaggregation simultaneously with an increased platelet lipid biosynthesis which might be related to lipid peroxidation. In the present study, we specifically studied the arachidonic acid and the fibrinolytic pathways in relation to the fatty acid composition in female rats treated for 6 weeks with OC (ethinyl estradiol plus lynestrenol). We found that platelets of treated animals were not only hyper-responsive to thrombin and ADP, but also to sodium arachidonate. In addition, the results of the thrombin-induced release of labeled arachidonic acid pre-…