Search results for "OXIDATION"
showing 10 items of 1913 documents
Selective effects of some anesthetics and detergents on lipid peroxidation of mouse heart homogenates.
1991
Abstract 1. 1. The effects of some anesthetics and detergents on the Fe2+/ascorbate-stimulated non-enzymatic lipid peroxidation potential and on the NADPH-dependent enzymatic lipid peroxidation capacity were characterized in mouse heart homogenates. 2. 2. Chlorpromazine turned out to be the most efficient inhibitor, causing a 50% inhibition at a concentration of 0.03 mM in the non-enzymatic assay, and at a concentration of 0.02 mM in the enzymatic assay. 3. 3. Tetracaine was about a 10-times weaker inhibitor with IC50-values of 0.25 mM. High concentration of dibucaine (1 mM) exerted a 60% inhibition in the non-enzymatic assay, but lidocaine and procaine had no prominent effect with the conc…
Role of HDL function and LDL atherogenicity on cardiovascular risk: a comprehensive examination
2019
[Background] High-density lipoprotein (HDL) functionality and low-density lipoprotein (LDL) atherogenic traits can describe the role of both particles on cardiovascular diseases more accurately than HDL- or LDL-cholesterol levels. However, it is unclear how these lipoprotein properties are particularly affected by different cardiovascular risk factors.
Cocaine hepatotoxicity: two different toxicity mechanisms for phenobarbital-induced and non-induced rat hepatocytes.
1993
Abstract Hepatocytes isolated from both phenobarbital-induced and control rats were short-term cultured and exposed to cocaine (8–2000 μM) for varying times. Intracellular lactate dehydrogenase activity, free calcium levels ([Ca 2+ ] i ), reduced glutathione (GSH) and lipid peroxidation were investigated to evaluate the toxic effect of cocaine on hepatocytes. Cytochrome P450 induction by phenobarbital potentiated the in vitro cytotoxicity of cocaine by a factor of 13 (IC 50 = 84 μ M induced cells vs 1100 μM in non-induced cells). This difference in the susceptibility of the two types of hepatocytes to cocaine correlated well with the activity of cytochrome P450 2 B 1 2 . Rapid depletion of …
Glutamine potentiates TNF-α-induced tumor cytotoxicity
2001
L-glutamine (Gln) sensitizes tumor cells to tumor necrosis factor (TNF)-alpha-induced cytotoxicity. The type and mechanism of cell death induced by TNF-alpha was studied in Ehrlich ascites tumor (EAT)-bearing mice fed a Gln-enriched diet (GED; where 30% of the total dietary nitrogen was from Gln). A high rate of Gln oxidation promotes a selective depletion of mitochondrial glutathione (mtGSH) content to approximately 58% of the level found in tumor mitochondria of mice fed a nutritionally complete elemental diet (standard diet, SD). The mechanism of mtGSH depletion involves a glutamate-induced inhibition of GSH transport from the cytosol into mitochondria. The increase in reactive oxygen in…
Kinetic experiments on the synergistic effect of NADH on microsomal drug oxidation.
1974
Abstract1. The synergistic effect of NADH on the NADPH-dependent mixed function oxidation of p-nitroanisole and hexobarbital can be measured both photometrically and by following the substrate-induced oxygen consumption. The increase in reaction rate is about 50% and lasts as long as NADH is present in the microsomal suspension.2. The oxidation of added NADH is increased by hexobarbital, ethylmorphine and SKF 525-A. Lineweaver-Burk transformation of the NADH oxidation rates yields straight lines for xenobiotic substrates suggesting Michaelis constants similar to those obtained from metabolic experiments. NADH oxidation in the absence of NADPH is about half as rapid as in its presence.3. Som…
Tissue oxygenation in brain, muscle and fat in a rat model of sleep apnea: differential effect of obstructive apneas and intermittent hypoxia.
2011
Study Objectives: To test the hypotheses that the dynamic changes in brain oxygen partial pressure (PtO 2) in response to obstructive apneas or to intermittent hypoxia differ from those in other organs and that the changes in brain PtO 2 in response to obstructive apneas is a source of oxidative stress. Design: Prospective controlled animal study. Setting: University laboratory. Participants: 98 Sprague-Dawley rats. Interventions: Cerebral cortex, skeletal muscle, or visceral fat tissues were exposed in anesthetized animals subjected to either obstructive apneas or intermittent hypoxia (apneic and hypoxic events of 15 s each and 60 events/h) for 1 h. Measurements and Results: Arterial oxyge…
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…
Enhanced lipid peroxidation and platelet activation as potential contributors to increased cardiovascular risk in the low-HDL phenotype
2013
Background Low high‐density lipoprotein ( HDL ) levels are major predictors of cardiovascular ( CV ) events, even in patients on statin treatment with low‐density lipoprotein ( LDL ) at target. In animal models HDL s protect LDL from oxidation and blunt platelet activation. Our study aimed to examine whether HDL levels are related to in vivo oxidative stress and platelet activation, as determinants of atherothrombosis. Methods and Results Urinary 8‐iso‐PGF 2α and 11‐dehydro‐TXB 2 , in vivo markers of oxidative stress and platelet activation, respectively, were measured in 65 coronary heart disease (CHD) normocholesterolemic patients with HDL ≤35 mg/ dL , and in 47 CHD patients with HDL >…
Characteristics of l-carnitine import into heart cells
2007
Abstract l -carnitine is an essential cofactor for the transport of fatty acids across the mitochondrial membranes. l -carnitine can be provided by food products or biosynthesized in the liver. After intestinal absorption or hepatic biosynthesis, l -carnitine is transferred to organs whose metabolism is dependent upon fatty acid oxidation, such as the skeletal muscle and the heart. The intracellular transport of l -carnitine into the cell requires specific transporters and today, several of these have been characterized. Most of them belong to the solute carrier family. Heart is one of the major target for carnitine transport and use, however basic properties of carnitine uptake by heart ce…
Fat oxidation at rest and during exercise in male monozygotic twins
2019
Abstract Purpose We aimed to investigate if hereditary factors, leisure-time physical activity (LTPA) and metabolic health interact with resting fat oxidation (RFO) and peak fat oxidation (PFO) during ergometer cycling. Methods We recruited 23 male monozygotic twin pairs (aged 32–37 years) and determined their RFO and PFO with indirect calorimetry for 21 and 19 twin pairs and for 43 and 41 twin individuals, respectively. Using physical activity interviews and the Baecke questionnaire, we identified 10 twin pairs as LTPA discordant for the past 3 years. Of the twin pairs, 8 pairs participated in both RFO and PFO measurements, and 2 pairs participated in either of the measurements. We quantif…