Search results for "SUPEROXIDE DISMUTASE"
showing 10 items of 296 documents
Mitochondrial reactive oxygen species are obligatory signals for glucose-induced insulin secretion.
2009
OBJECTIVE—Insulin secretion involves complex events in which the mitochondria play a pivotal role in the generation of signals that couple glucose detection to insulin secretion. Studies on the mitochondrial generation of reactive oxygen species (ROS) generally focus on chronic nutrient exposure. Here, we investigate whether transient mitochondrial ROS production linked to glucose-induced increased respiration might act as a signal for monitoring insulin secretion. RESEARCH DESIGN AND METHODS—ROS production in response to glucose was investigated in freshly isolated rat islets. ROS effects were studied using a pharmacological approach and calcium imaging. RESULTS—Transient glucose increase …
Cell death and oxidative stress in gliomas.
1999
In gliomas, apoptosis and necrosis are determined by a number of promoting and inhibiting factors including oxidative cell stress mediated by nitric oxide synthases (NOS) and reduced by superoxide dismutases. Therefore, in 46 gliomas (including astrocytomas, oligodendrogliomas, oligo-astrocytomas, and glioblastomas), the relationship of apoptosis and necrosis and the expression of apoptosis-promoting (p53, bax, Fas, Fas-L) and inhibiting (bcl-2) factors as well as of different isoforms of NOS (NOSb, NOSe, NOSi) and manganese superoxide dismutase (MnSOD) were studied. Apoptosis was measured in situ by the TUNEL method while expression profiles of apoptosis-related and oxidative stress-associ…
Beneficial effect of dipyridyl, a liposoluble iron chelator against focal cerebral ischemia: In vivo and in vitro evidence of protection of cerebral …
2007
Whereas iron chelators were shown to induce neuroprotection against brain injury, the effect of iron chelators on ischemia-induced damage of cerebral endothelium is largely unknown. Our objective was to explore the endothelioprotective effect of the lipophilic iron chelator dipyridyl (DP) (i) in vitro on the death of cerebral endothelial cells (CECs) subjected to intracellular iron loading and (ii) in vivo on the ischemia-induced blood-brain barrier (BBB) disruption. When given shortly after iron exposure or brain ischemia, DP prevented the death of CECs and diminished BBB disruption, respectively, whereas a delayed administration of DP was associated with a lower CECs protection. Interesti…
Bcl-2 and Mn-SOD antisense oligodeoxynucleotides and a glutamine-enriched diet facilitate elimination of highly resistant B16 melanoma cells by tumor…
2005
Mitochondrial glutathione (mtGSH) depletion increases sensitivity of Bcl-2-overexpressing B16 melanoma (B16M)-F10 cells (high metastatic potential) to tumor necrosis factor-alpha (TNF-alpha)-induced oxidative stress and death in vitro. In vivo, mtGSH depletion in B16M-F10 cells was achieved by feeding mice (where the B16M-F10 grew as a solid tumor in the footpad) with an L-glutamine (L-Gln)-enriched diet, which promoted in the tumor cells an increase in glutaminase activity, accumulation of cytosolic L-glutamate, and competitive inhibition of GSH transport into mitochondria. L-Gln-adapted B16M-F10 cells, isolated using anti-Met-72 monoclonal antibodies and flow cytometry-coupled cell sortin…
Proteome analysis of myocardial tissue following ischemia and reperfusion--effects of complement inhibition.
2006
Myocardial ischemia-reperfusion injury can be related to complement activation with generation of chemotactic mediators, release of cytokines, leukocyte accumulation, and subsequent severe tissue injury. In this regard, activation of transcription factors (i.e., NFkappaB) and de novo protein synthesis or inflammatory protein degradation seems to play an important role. In the present study, we analyzed the cardiac protein expression following myocardial ischemia (60 min) and reperfusion (180 min) in a rabbit model utilizing two-dimensional electrophoresis and nanoHPLC/ESI-MS/MS for biochemical protein identification. To achieve cardioprotective effects, we used a novel highly selective smal…
Reduction of mdx mouse muscle degeneration by low-intensity endurance exercise: a proteomic analysis in quadriceps muscle of exercised versus sedenta…
2015
By proteomic analysis we found an up-regulation of four carbonic anhydrase-3 (CA3) isoforms and a down-regulation of superoxide dismutase [Cu-Zn] (SODC) in quadriceps of sedentary X-linked muscular dystrophy (mdx) mice as compared with wild–type (WT) mice and the levels were significantly restored to WT values following low-intensity endurance exercise.
Retinal oxidation, apoptosis and age- and sex-differences in the mnd mutant mouse, a model of neuronal ceroid lipofuscinosis
2004
Retinal degeneration is an early and progressive event in many forms of neuronal ceroid lipofuscinoses (NCLs), a heterogeneous group of neurodegenerative disorders with unknown pathogenesis. We here used the mutant motor neuron degeneration (mnd) mouse, a late-infantile NCL variant, to investigate the retinal oxidative state and apoptotic cell death as a function of age and sex. Total superoxide dismutase (SOD) activities and thiobarbituric acid-reactive substance (TBARS) levels revealed progressive increases in retinal oxyradicals and lipid peroxides of mnd mice of both sexes. Female mnd retinas showed a higher oxidation rate and consistently exhibited the 4-hydroxy-2-nonenal (4-HNE)-adduc…
Glutathione Peroxidase 1 Activity and Cardiovascular Events in Patients With Coronary Artery Disease
2003
Along with superoxide dismutase, glutathione peroxidase 1 is one of the cellular antioxidant enzymes that have a key role in controlling reactive oxygen species. It uses glutathione to reduce hydrogen peroxide to water and lipid peroxides to their respective alcohols. There are suggestions from in vitro and animal studies that these enzymes could protect against atherosclerosis. This prospective study examined the possibility that relatively high activity of antioxidant enzymes protects against cardiovascular events. The study population included 636 patients suspected of having coronary artery disease who were followed for a median period of 4.7 years. Stable angina was present in 510 pati…
Mucositis and salivary antioxidants in patients undergoing bone marrow transplantation (BMT)
2014
Objectives: High doses of chemotherapy generate DNA damage in patients undergoing bone marrow transplantation (BMT), due to the production of reactive oxygen species (ROS). In order to evaluate the local defensive effectiveness of the patient undergoing BMT, the concentrations of the antioxidants superoxide dismutase (SOD) and uric acid (UA) were measured in saliva. Study Design: Basal saliva samples were collected from 20 patients undergoing BMT at the Oncology Depart- ment, Sanatorio Allende (Córdoba), in the stages: initial, prior to conditioning therapy (I); middle: 7 to 10 days after BMT (M) and final stage, 30 days after discharge from isolation (F). SOD levels were determined using a…
Mutagenicity spectra in Salmonella typhimurium strains of glutathione, L-cysteine and active oxygen species
1989
Glutathione and L-cysteine, in the presence of rat kidney post-mitochondrial supernatant (S9) fraction, and various forms of active oxygen were investigated for mutagenicity in seven his- strains of Salmonella typhimurium. Glutathione and L-cysteine showed qualitatively and quantitatively virtually identical mutagenic activities. The number of mutants induced in strain TA97 was 3-4 times higher than in TA100, the strain in which the mutagenicity was originally detected. Mutagenic effects were also observed in strains TA92, TA102 and TA104, but not in TA1535 and TA1537. Hydrogen peroxide, superoxide and glucose/glucose oxidase in the presence and absence of kidney S9 fraction showed pronounc…