Search results for "Glutathion"
showing 10 items of 744 documents
Mitochondrial oxidative stress plays a key role in aging and apoptosis
2000
Harman first suggested in 1972 that mitochondria might be the biological clock in aging, noting that the rate of oxygen consumption should determine the rate of accumulation of mitochondrial damage produced by free radical reactions. Later in 1980 Miquel and coworkers proposed the mitochondrial theory of cell aging. Mitochondria from postmitotic cells use O2 at a high rate, hence releasing oxygen radicals that exceed the cellular antioxidant defences. The key role of mitochondria in cell aging has been outlined by the degeneration induced in cells microinjected with mitochondria isolated from fibroblasts of old rats, especially by the inverse relationship reported between the rate of mitoch…
Correlation between superoxide dismutase, glutathione peroxidase and catalase in isolated rat hepatocytes during fetal development
1981
Abstract Superoxide dismutase, glutathione peroxidase and catalase activities were determined in isolated fetal rat hepatocytes of various ages and compared with the values of neonatal and adult cells. The developmental pattern of superoxide dismutase and glutathione peroxidase were very similar with a low constant activity in the fetal cells and a postnatal burst. On the contrary catalase begins to increase already since the 18th day of the fetal life. The results suggest a functional correlation of superoxide dismutase and glutathione peroxidase in the antioxidative enzyme defense of liver cells.
Senile cataract: a review on free radical related pathogenesis and antioxidant prevention
1990
Abstract Glutathione metabolism plays an essential role in the homeostasis of the lens. Thus, it is not surprising that experimental depletion of this substance leads to a process of lens disorganization similar to senile cataract and that in all types of irreversible cataract there is a decrease in the glutathione content of the lens. Therefore, it may be useful in preventive geriatrics to raise the glutathione concentration of the lens and, since glutathione monoethyl ester can cross the capsule and membranes of the lens, administration of this compound may be the treatment of choice. This could be complemented by long-term administration of small doses of acetylsalicylic acid, in the ear…
Glutathione, oxidative stress and aging
1996
The free radical theory of aging proposes that the impairment in physiological performance associated with aging is caused by the detrimental effects of oxygen free radicals. This is interesting because it provides us with a theoretical framework to understand aging and because it suggests a rationale for intervention, i.e., antioxidant administration. Thus, the study of antioxidant systems of the cell may be very important in gerontological studies. Glutathione is one of the main nonprotein antioxidants in the cell which, together with its related enzymes, constitute the “glutathione system.” The involvement of glutathione in aging has been known since the early seventies. Several studies …
Pharmacological intervention in age-associated brain disorders by Flupirtine: Alzheimer’s and Prion diseases
1998
Alzheimer's disease, a major form of dementia in the elderly has become an increasingly important health problem in developed countries. In vitro studies on primary neurons demonstrate that Flupirtine (Katadolon) at a concentration of 1 microg/ml, significantly reduces the neurotoxic (apoptotic) effect displayed by A beta25-35, a segment of the amyloid beta-protein precursor the etiologic agent of Alzheimer's disease. Flupirtine, which has been in clinical use since 10 years ago, prevents the toxic effect of PrP, the presumed etiologic agent of the Creutzfeldt-Jakob disease as well as the excitatory amino acid glutamate on cortical neurons. Flupirtine displays a bimodal activity. Its strong…
Molecular bases of the treatment of Alzheimer's disease with antioxidants: prevention of oxidative stress
2004
Alzheimer's disease is associated with a systemic oxidative stress situation which can be followed in vivo by determining biomarkers such as plasma lipoperoxides and TBARS levels and the oxidation degree of glutathione in red blood cells. It has been observed that Alzheimer's patients show an increased level of plasma TBARS, which indicates a higher free radical oxidation of plasma unsaturated phospholipids, and an increased oxidation of red blood cells glutathione, which indicates oxidative stress in peripheral cells. This latter, glutathione oxidation, was found to correlate statistically with the cognitive status of the patients. Treatment with vitamin E resulted in an improved cognitive…
Age-Related Changes of Liver Antioxidant Enzymes and 8-Hydroxy-2-Deoxyguanosine During FetalNeonate Transition and Early Rat Development
2000
We have studied the pro-antioxidant status of the rat liver on the last day of gestation and at 1, 15, and 30 days of extrauterine life. Representative variables, such as activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase and concentrations of reduced glutathione and 8-hydroxy-2'-deoxyguanosine, were determined in liver to assess the degree of birth-associated oxidative stress during the fetal-neonatal transition and early development of the rat. Percentages by which liver Cu/ZnSOD activity increased over the basal value of the fetal liver were 54%, 95%, and 127% at neonatal days 1, 15, and 30, respectively. There was a lack of induction in the development profil…
The Effect of Moderate- Versus High-Intensity Resistance Training on Systemic Redox State and DNA Damage in Healthy Older Women
2018
This study investigated effects of a 16-week progressive resistance training program (RTP) with elastic bands at two different intensities on systemic redox state, DNA damage, and physical function in healthy older women. Methods: Participants were randomly assigned to the high-intensity group (HIGH; n = 39), moderate-intensity group (MOD; n = 31), or control group (CG; n = 23). The exercise groups performed an RTP twice a week with three to four sets of 6 (HIGH) or 15 (MOD) repetitions of six overall body exercises at a perceived exertion rate of 8–9 on the OMNI-Resistance Exercise Scale for use with elastic bands. Thiol redox state was determined by reduced glutathione (GSH), oxidized gl…
Physiological changes in glutathione metabolism in foetal and newborn rat liver
1991
Glutathione metabolism was studied in isolated hepatocytes from foetal, newborn and adult rats. The GSH/GSSG ratio decreased 15-20-fold through the foetal-neonatal-adult transition. This was mainly due to an increase in GSSG. All enzyme activities involved in the glutathione redox cycle tend to increase during that transition, but the relative increases in glutathione peroxidase and glutathione S-transferase were 3-5 times those of glutathione reductase or glucose-6-phosphate dehydrogenase. GSH synthesis from methionine as a sulphur source was 6 times lower in foetal than in adult hepatocytes. However, when N-acetylcysteine was used as a sulphur donor to by-pass the cystathionine pathway, t…
Age-associated oxidative damage leads to absence of γ-cystathionase in over 50% of rat lenses: Relevance in cataractogenesis
2004
Oxidative damage to lens proteins and glutathione depletion play a major role in the development of senile cataract. We previously found that a deficiency in gamma-cystathionase activity may be responsible for glutathione depletion in old lenses. The aims of this study were: (1) to investigate the mechanism that causes the age-related deficiency in gamma-cystathionase activity in the eye lens, and (2) to determine the role of gamma-cystathionase deficiency in cataractogenesis. Two populations of old rats were found, one (56%) whose lenses lacked gamma-cystathionase activity and the rest that exhibited detectable enzyme activity. gamma-Cystathionase protein was absent in lenses from old rats…