Search results for "Peroxidation"
showing 10 items of 308 documents
Effect of acidosis on lipid peroxidation in brain slices.
1991
Acidification of the incubation medium markedly increased lipid peroxidation of cortical brain slices. Lactic acidosis caused a more extensive lipid peroxidation than did phosphoric acidosis (+35% at pH 6 and +81% at pH 5), probably due to the rapid diffusion of the protonated form of lactic acid across cell membranes. These results support the hypothesis that free radical mechanisms may be involved in the cytotoxicity of acidosis.
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 …
Arylesterase Activity and Antioxidant Status Depend on PON1-Q192R and PON1-L55M Polymorphisms in Subjects with Increased Risk of Cardiovascular Disea…
2007
Human paraoxonase (PON1) exists in 2 major polymorphic forms and has been shown to protect LDL and HDL against oxidation. The aim of this study was to assess the differences between subjects at increased risk of cardiovascular disease (CVD), taking into account the effects of PON1-Q192R and PON1-L55M polymorphisms on 1) basal serum arylesterase activity, lipid peroxidation (LPO), and LDL-cholesterol (LDL-C), HDL-C, total cholesterol (TC), and oxidized-LDL (ox-LDL) concentrations; 2) the relations between arylesterase activity and lipid variables; and 3) the effect of walnut-enriched meat (WM) consumption on arylesterase activity and lipid variables. Twenty-three Caucasians at increased risk…
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…
Erythrocyte deformability, plasma lipid peroxidation and plasma protein oxidation in a group of OSAS subjects
2016
Considering that obstructive sleep apnea syndrome (OSAS) is usually associated with endothelial dysfunction, atherosclerosis and cardiovascular disorders, our aim was to examine the erythrocyte deformability and the oxidative status in a group of OSAS subjects. We consecutively enrolled 48 subjects with OSAS defined after a 1-night cardiorespiratory sleep study, subsequently subdivided according to the apnea/hypopnea index (AHI) value in two subgroups: Low (L = 21 subjects with AHI30) and High (H = 27 subjects with AHI30). We evaluated the erythrocyte deformability, expressed as elongation index (EI) and the parameters of the oxidative status, such as lipid peroxidation (expressed as thioba…
Elastase, myeloperoxidase, nitric oxide metabolites and oxidative status in subjects with clinical stable chronic renal failure on conservative treat…
2009
We evaluated, in a group of 41 CRF undialyzed subjects (29 men and 12 women, mean age 64.1 +/- 11.3 years), some parameters that reflect leukocyte activation (elastase, myeloperoxidase - MPO), plasma NO metabolites (NO(x)) and the oxidative status (lipid peroxidation expressed as thiobarbituric acid-reactive substances (TBARS) and total antioxidant status (TAS). Elastase was determined, on plasma separated from fasting venous blood, as elastase/alpha1-proteinase inhibitor complex. MPO was evaluated employing the Myeloperoxidase ELISA kit. The NO production was evaluated by a micromethod. The oxidation of polyunsaturated fatty acids was evaluated in plasma by detection of the thiobarbituric …
Lipid peroxidation and nitric oxide metabolites in a group of subjects with obstructive sleep apnea syndrome.
2015
It is known that in OSAS the plasma lipid peroxidation has an opposite behavior in comparison with nitric oxide metabolites. In the re-examination of our survey of OSAS subjects we calculated the ratio between thiobarbituric acid reactive substances (TBARS) and nitric oxide metabolites (NOx) in relation to OSAS severity. The study has regarded 48 OSAS subjects subdivided in two subgroups according to the apnea/hypopnea index - AHI- (Low = 21 subjects with AHI30 and High = 27 subjects with AHI30). From the obtained data it is evident that the TBARS/NOx ratio is significantly higher in the H subgroup compared to L subgroup as well as this ratio is reduced in L subgroup in comparison with the …
Postischemic application of lipid peroxidation inhibitor U-101033E reduces neuronal damage after global cerebral ischemia in rats.
1998
Background and Purpose —The lipid peroxidation inhibitor U-101033E was examined for effects on cerebral blood flow (CBF), cortical tissue hemoglobin oxygen saturation (HbS o 2 ), and neuronal damage. Methods —Fifteen minutes of global cerebral ischemia was induced by two-vessel occlusion and hypobaric hypotension. Wistar rats (n=25) were randomized to receive vehicle (n=9) or 40 mg/kg U-101033E (n=9) intraperitoneally during 2 hours of reperfusion. A sham group (n=7) had neither ischemia nor therapy. Histology was evaluated 7 days after ischemia. Results —During late hyperperfusion (at 17 minutes), vehicle-treated animals had a higher ( P =0.044) cortical tissue HbS o 2 (72.0±1.4%) than di…
Chronic ethanol feeding induces cellular antioxidants decrease and oxidative stress in rat peripheral nerves. Effect of S-adenosyl-L-methionine and N…
1998
Chronic ethanol feeding promotes oxidative stress in rat peripheral nerve. Malondialdehyde, a lipid peroxidation product, content increases in sciatic nerves of rats fed an ethanol-containing diet, when compared with pair-fed animals. Moreover, glutathione content and glutathione peroxidase activity in this same tissue decrease in ethanol-fed vs. pair-fed rats. S- adenosyl-L-methionine and N-acetyl-L-cysteine, both with possible therapeutic action on alcoholism, were tested in this animal model. Only N-acetyl-L- cysteine was able to normalize malondialdehyde content and to restore glutathione content and glutathione peroxidase activity, to values not significantly different from those of sc…