Search results for "GPX"

Cigarette smoking affects specific sperm oxidative defenses but does not cause oxidative DNA damage in infertile men

2008

Objective To evaluate the effects of tobacco consumption on the oxidative defenses of sperm, the glutathione system (GS), and sperm DNA oxidation. Design Double-blind experimental study. Setting Andrology laboratory in a university-affiliated private setting. Patient(s) One hundred seventeen semen samples from infertile males. Intervention(s) None. Main Outcome Measure(s) (a) sperm GS enzymatic activity with respect to glutathione peroxidase isoforms GPx-1 and GPx-4, glutathione reductase (GR), and cellular glutathione (GSH) content (n = 29); (b) GPx-1, GPx-4, and GR m RNA expression analysis (n = 33); (c) oxidative DNA damage quantification using OXIDNA assay kit (n = 55). Two groups were …

Mesenchymal Stem Cells Improve Motor Functions and Decrease Neurodegeneration in Ataxic Mice

2014

The main objective of this work is to demonstrate the feasibility of using bone marrow-derived stem cells in treating a neurodegenerative disorder such as Friedreich's ataxia. In this disease, the dorsal root ganglia of the spinal cord are the first to degenerate. Two groups of mice were injected intrathecally with mesenchymal stem cells isolated from either wild-type or Fxntm1Mkn/Tg(FXN)YG8Pook (YG8) mice. As a result, both groups presented improved motor skills compared to nontreated mice. Also, frataxin expression was increased in the dorsal root ganglia of the treated groups, along with lower expression of the apoptotic markers analyzed. Furthermore, the injected stem cells expressed th…

Maternal Treatment of Spontaneously Hypertensive Rats With Pentaerythritol Tetranitrate Reduces Blood Pressure in Female Offspring

2014

Pentaerythritol tetranitrate is devoid of nitrate tolerance and shows no reproductive or developmental toxicity in animal studies. Recently, pentaerythritol tetranitrate has been demonstrated to reduce the risk of intrauterine growth restriction and the risk of preterm birth in women with abnormal placental perfusion. This study was conducted to test the perinatal programming effect of pentaerythritol tetranitrate in spontaneously hypertensive rats, a rat model of genetic hypertension. Parental spontaneously hypertensive rats were treated with pentaerythritol tetranitrate (50 mg/kg per day) during pregnancy and lactation periods; the offspring received standard chow without pentaerythritol …

Glutathione Peroxidase-1 Activity, Atherosclerotic Burden, and Cardiovascular Prognosis

2007

Recent findings suggest that erythrocyte intracellular glutathione peroxidase-1 (GPX-1) activity is related inversely to future cardiovascular events. The aim of this study is to evaluate the association of GPX-1 activity to extent of atherosclerosis, as well as its long-term prognosis in context with atherosclerotic burden. In a prospective study, we included 508 patients before coronary angiography. Atherosclerosis of carotid and leg arteries was documented using sonographic methods. Blood samples were drawn after an overnight fasting period, and GPX-1 activity was determined in washed erythrocytes. GPX-1 activity tended to decrease with increasing numbers of atherosclerotic vascular beds…

Does Empagliflozin Modulate Leukocyte–Endothelium Interactions, Oxidative Stress, and Inflammation in Type 2 Diabetes?

2021

Sodium-glucose co-transporter 2 inhibitors (iSGLT2) have been linked to cardiovascular risk reduction in patients with type 2 diabetes (T2D). However, their underlying molecular mechanisms remain unclear. This study aimed to evaluate the effects of empagliflozin, a novel potent and selective iSGLT-2, on anthropometric and endocrine parameters, leukocyte–endothelium interactions, adhesion molecules, ROS production, and NFkB-p65 transcription factor expression. According to standard clinical protocols, sixteen T2D patients receiving 10 mg/day of empagliflozin were followed-up for 24 weeks. Anthropometric and analytical measurements were performed at baseline, 12 weeks, and 24 weeks. Interacti…

Chronic ethanol feeding causes oxidative stress in rat liver mitochondria. Prevention by S-adenosyl methionine

1999

Control of the ribulose 1,5-bisphosphate carboxylase/oxygenase activity by the chloroplastic glutathione pool.

2014

The CO2-fixing activity of ribulose 1,5-bisphosphate carboxylase/oxygenase depends on the redox state of its cysteines. Disulfides like cystamine or 5,5'-dithio-bis(2-nitrobenzoic acid), but not oxidized glutathione, switch the enzyme to the inactive oxidized form. Conversely, thiols like cysteamine, cysteine, dithiotreitol or 2-mercaptoethanol, but not reduced glutathione, recover enzymatic activity after a previous oxidation. Direct regulation of the carboxylase activity by the chloroplastic glutathione pool is hindered by kinetic barriers impeding access to the critical residues. However, reduced glutathione can drive the recovery of activity by means of minute amounts of smaller interme…

Recombinant hydroperoxide lyase for the production of aroma compounds: Effect of substrate on the yeast Yarrowia lipolytica

2008

International audience; The aim of this study was to investigate the action mechanism of linoleic acid hydroperoxides (HPOD), which are the major substrates of hydroperoxide lyase for the production of flavour compounds, on the yeast Yarrowia lipolytica by evaluating their effect on the oxidative state of the cells. The total antioxidant capacity (TAC) and the activity of the main antioxidant enzymes, such as glutathione reductase, glutathione peroxidase and superoxide dismutase, of cells treated with HPOD were studied. The potential role of intracellular glutathione, including reduced glutathione (GSH) and oxidized glutathione (GSSG), in conferring HPOD resistance was also been examined. T…

4-hydroxynonenal inhibits glutathione peroxidase: protection by glutathione

1999

Abstract 4-Hydroxy-2,3-trans-nonenal, a lipid peroxidation product, inhibits glutathione peroxidase in a concentration-dependent manner. The concentration providing 50% inhibition is 0.12 mM. This inhibition can be almost completely (89%) prevented by 1 mM glutathione added to the incubation mixture 30 min before 4-hydroxy-2,3-trans-nonenal or 2,3-trans-nonenal, but not by other thiol-containing antioxidants such as 0.5 mM dithiothreitol or β-mercaptoethanol. Again the addition of 1 mM glutathione, and not of 0.5 mM dithiothreitol or β-mercaptoethanol, to the enzyme 30 min after incubation with 4-hydroxy-2,3-trans-nonenal restores activity to the same extent as does the preincubation with G…

Selenium supplementation improves antioxidant capacity in vitro and in vivo in patients with coronary artery disease

2008

Background Selenium is a central determinant of antioxidative glutathione peroxidase 1 (GPx-1) expression and activity. The relevance of selenium supplementation on GPx-1 in coronary artery disease (CAD) needs to be established. We assessed the effect of selenium supplementation on GPx-1 in cell culture and on endothelial function in a prospective clinical trial. Methods Human coronary artery endothelial cells were incubated with 5.78 to 578 nmol/L sodium selenite, Se-methyl-selenocysteine hydrochloride, or seleno-l-methionine. Glutathione peroxidase 1 mRNA and protein expression and activity were measured. Coronary artery disease patients (n = 465) with impaired endothelial function (flow-…