0000000000594826
AUTHOR
Elena Domenech
Moderate exercise is an antioxidant: Upregulation of antioxidant genes by training
Exercise causes oxidative stress only when exhaustive. Strenuous exercise causes oxidation of glutathione, release of cytosolic enzymes, and other signs of cell damage. However, there is increasing evidence that reactive oxygen species (ROS) not only are toxic but also play an important role in cell signaling and in the regulation of gene expression. Xanthine oxidase is involved in the generation of superoxide associated with exhaustive exercise. Allopurinol (an inhibitor of this enzyme) prevents muscle damage after exhaustive exercise, but also modifies cell signaling pathways associated with both moderate and exhaustive exercise in rats and humans. In gastrocnemius muscle from rats, exerc…
Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance
Background Exercise practitioners often take vitamin C supplements because intense muscular contractile activity can result in oxidative stress, as indicated by altered muscle and blood glutathione concentrations and increases in protein, DNA, and lipid peroxidation. There is, however, considerable debate regarding the beneficial health effects of vitamin C supplementation. Objective This study was designed to study the effect of vitamin C on training efficiency in rats and in humans. Design The human study was double-blind and randomized. Fourteen men (27-36 y old) were trained for 8 wk. Five of the men were supplemented daily with an oral dose of 1 g vitamin C. In the animal study, 24 mal…
Age-related increase in xanthine oxidase activity in human plasma and rat tissues.
This study assessed the role of xanthine oxidase in vascular ageing. A positive correlation between xanthine oxidase activity and age was found in human plasma. Similar results were found in rat plasma. Xanthine oxidase expression and activity in homogenates from the aortic wall were significantly higher in samples from old rats than in their young counterparts (p<0.01). In rat skeletal muscle homogenates both xanthine oxidase expression and activity showed a similar age-related profile. Superoxide production by xanthine oxidase in aortic rings was higher in aged rats. Uric acid, the final product of xanthine oxidase has been proposed as a risk factor for coronary heart disease and an indep…
Exercise as an antioxidant: it up-regulates important enzymes for cell adaptations to exercise
Abstract Aims. – To assess the role of the reactive oxygen species (ROS) in cell signalling and in the regulation of gene expression. Methods. – Exercise causes oxidative stress only when exhaustive. Strenuous exercise causes oxidation of glutathione, release of cytosolic enzymes, and other signs of cell damage. We have tested this hypothesis by studying the effect of inhibition of ROS production by allopurinol (an inhibitor of xanthine oxidase, a free radical generating enzyme) on cell signalling pathways in marathon runners and in rats submitted to exhaustive exercise by running on a treadmill. Results. – Exercise caused an activation of NF-κB in lymphocytes from marathon runners which wa…
Increased oxidative stress levels and normal antioxidant enzyme activity in circulating mononuclear cells from patients of familial hypercholesterolemia
Familial hypercholesterolemia (FH) is a clinical condition with high risk for developing atherosclerosis. Increased oxidative stress (OS) and FH have been related to atherosclerosis, but no data are available on levels of OS and antioxidant enzyme activity in circulating mononuclear cells (CMCs) from FH patients. Circulating mononuclear cells are important mediators in atherosclerosis development, and chronically increased blood OS present in FH can induce modification in CMC activity. The objective of the study was to analyze the OS levels in CMCs from FH patients and controls. We have selected 30 nonrelated FH index patients and 30 normoglycemic and normocholesterolemic controls matched b…
Bemiparin improves the total antioxidant status in plasma
The aim of this work is to test the protective effect of bemiparin (3500 I.U., s.c.) against oxidative stress in plasma from healthy volunteers. We have evaluated the total antioxidant activity in plasma, superoxide dismutase and glutathione peroxidase activities, and oxidized glutathione and malondialdehyde levels, in two groups: treated (n=20) and control (n=15). Blood samples were collected at: basal, 2, 4, 6, 8 and 10 h. Total antioxidant activity and antioxidant enzymes activity were higher in the treated group at 2-6 h. However, oxidized glutathione and malondialdehyde levels were lower in the treated group at same times. The results suggest that bemiparin exerts an early beneficial e…