Search results for "oxidation"

Impaired plasma nitric oxide availability and extracellular superoxide dismutase activity in healthy humans with advancing age

2006

This study is aimed to verify the modifications of extracellular superoxide dismutase (EC-SOD) activity and its potential involvement on the mechanism responsible for the impairment of plasma nitric oxide (NO) availability occurring with advancing age in healthy humans. For this purpose, plasma samples were drawn from 40 healthy men, aged 20-92 years, in fasting state and used for measurements of stable end-product nitrite/nitrate (NOx), as expression of NO availability, EC-SOD activity, thiobarbituric acid reactive substances (TBARS) as marker of lipid peroxidation, Trolox equivalent antioxidant capacity (TEAC) as a measure of plasma total antioxidant capacity, and in vitro susceptibility …

Lipid Peroxidation, Nitric Oxide Metabolites, and Their Ratio in a Group of Subjects with Metabolic Syndrome

2014

Our aim was to evaluate lipid peroxidation, expressed as thiobarbituric acid-reactive substances (TBARS), nitric oxide metabolites (nitrite + nitrate) expressed asNOx, and TBARS/NOxratio in a group of subjects with metabolic syndrome (MS). In this regard we enrolled 106 subjects with MS defined according to the IDF criteria, subsequently subdivided into diabetic (DMS) and nondiabetic (NDMS) and also into subjects with a low triglycerides/HDL-cholesterol (TG/HDL-C) index or with a high TG/HDL-C index. In the entire group and in the four subgroups of MS subjects we found an increase in TBARS andNOxlevels and a decrease in TBARS/NOxratio in comparison with normal controls. Regarding all these …

Neddylation inhibition ameliorates steatosis in NAFLD by boosting hepatic fatty acid oxidation via the DEPTOR-mTOR axis

2021

Objective Neddylation is a druggable and reversible ubiquitin-like post-translational modification upregulated in many diseases, including liver fibrosis, hepatocellular carcinoma, and more recently, non-alcoholic fatty liver disease (NAFLD). Herein, we propose to address the effects of neddylation inhibition and the underlying mechanisms in pre-clinical models of NAFLD. Methods Hepatic neddylation measured by immunohistochemical analysis and NEDD8 serum levels measured by ELISA assay were evaluated in NAFLD clinical and pre-clinical samples. The effects of neddylation inhibition by using a pharmacological small inhibitor, MLN4924, or molecular approaches were assessed in isolated mouse hep…

Oxidative status in nondiabetic middle-aged subjects with metabolic syndrome: preliminary data.

2013

In vivoprooxidant state in Werner syndrome (WS): Results from three WS patients and two WS heterozygotes

2005

The hypothesis was tested that Werner syndrome (WS) phenotype might be associated with an in vivo prooxidant state. A set of redox-related endpoints were measured in three WS patients, two of their parents, and 99 controls within a study of some cancer-prone and/or ageing-related genetic disorders. The following analytes were measured: (a) leukocyte 8-hydroxy-2'-deoxyguanosine; (b) glutathione from whole blood, and (c) plasma levels of glyoxal, methylglyoxal, 8-isoprostane, and some plasma antioxidants (uric acid, ascorbic acid, alpha- and gamma-tocopherol). Leukocyte 8-hydroxy-2'-deoxyguanosine levels showed a significant increase in the 3 WS patients vs. 85 controls (p<10(-7)). The disulf…

Effect of Age and Lipoperoxidation in Rat and Human Adipose Tissue-Derived Stem Cells

2020

A wide range of clinical applications in regenerative medicine were opened decades ago with the discovery of adult stem cells. Highly promising adult stem cells are mesenchymal stem/stromal cells derived from adipose tissue (ADSCs), primarily because of their abundance and accessibility. These cells have multipotent properties and have been used extensively to carry out autologous transplants. However, the biology of these cells is not entirely understood. Among other factors, the regeneration capacity of these cells will depend on both their capacity of proliferation/differentiation and the robustness of the biochemical pathways that allow them to survive under adverse conditions like thos…

Effects of gender on resting leg blood flow: implications for measurement of regional substrate oxidation.

1998

Jensen, Michael D., Tu T. Nguyen, A. Hernández Mijares, C. Michael Johnson, and Michael J. Murray. Effects of gender on resting leg blood flow: implications for measurement of regional substrate oxidation. J. Appl. Physiol. 84(1): 141–145, 1998.—These studies were designed to examine whether the respiratory quotient (RQ) of leg tissue (primarily skeletal muscle) would increase to a greater degree in women than in men during meal ingestion. We found that mean leg and systemic RQ values were similar in men under both basal and fed conditions, whereas the agreement was poor in women. In women, leg RQ values tended to be greater than the systemic RQ, whereas splanchnic RQ values tended to be l…

Oxyphytosterols are present in plasma of healthy human subjects

2004

The oxidised derivatives of phytosterols (oxyphytosterols) were identified in plasma samples from thirteen healthy human volunteers, using MS. All the samples contained noticeable quantities of (24R)-5b,6b-epoxy-24-ethylcholestan-3b-ol (b-epoxysitostanol) and (24R)-ethylcholestan-3b,5a,6b-triol (sitostanetriol) and also trace levels of (24R)-5a,6a-epoxy-24-ethylcholestan-3b-ol (a-epoxysitostanol), (24R)-methylcholestan-3b,5a,6b-triol (campestanetriol) and (24R)-ethylch olest-5-en-3b-ol-7-one(7-ketositosterol). The amounts of these oxyphytosterols in plasma varied from 4·8 to 57·2 ng/ml. There are two possibilities concerning the origin of these compounds. First, they could come from the sma…

Pharmacokinetics and bioavailability of benperidol in schizophrenic patients after intravenous and two different kinds of oral application

1994

Pharmacokinetics and bioavailability of benperidol were determined in 13 schizophrenic patients after acute administration of 6 mg benperidol as an intravenous (i.v.) bolus injection, orally as liquid, and orally as tablets using a partially randomized cross-over design. Drug plasma levels were determined by high performance liquid chromatography with electrochemical detection and subjected to model independent pharmacokinetic analyses. After i.v. dosing the geometric means (mean-g) were 3.2 min for the distribution half-life, 5.80 h for the elimination half-life (t1/2 beta), 4.21 l/kg for the distribution volume, 7.50 h for the mean residence time (MRT), and 0.50 l/(h*kg) for the clearance…

Uncoupling protein-2 (UCP2) induces mitochondrial proton leak and increases susceptibility of non-alcoholic steatohepatitis (NASH) liver to ischaemia…

2008

Background: The mechanisms of progression from fatty liver to steatohepatitis and cirrhosis are not well elucidated. Mitochondrial dysfunction represents a key factor in the progression of non-alcoholic steatohepatitis (NASH) as mitochondria are the main cellular site of fatty acid oxidation, ATP synthesis and reactive oxygen species (ROS) production. Aims: (1) To evaluate the role of the uncoupling protein 2 in controlling mitochondrial proton leak and ROS production in NASH rats and humans; and (2) to assess the acute liver damage induced by ischaemia–reperfusion in rats with NASH. Methods: Mitochondria were extracted from the livers of NASH humans and rats fed a methionine and choline de…