Search results for "oxidative phosphorylation"
showing 10 items of 284 documents
Electron transport chain in aerobically cultivated Zymomonas mobilis
1996
Respiratory chain composition and energy coupling in cytoplasmic membrane of Zymomonas mobilis was shown to depend on culture aeration. Aerobically grown cells contained mainly the non-energy-generating NADH dehydrogenase with kM for NADH 58 mM. In anaerobically cultivated bacteria, the energy-coupling NADH dehydrogenase complex with km for NADH 7 mM predominated. In aerobically cultivated Z. mobilis, CoQ content and absorption peaks of cytochromes at 554–556 nm and 525–528 nm were significantly increased. Energy-coupling site I, linked to the NADH:CoQ oxidoreductase complex, could be eliminated under sulfate-deficient cultivation conditions. For anaerobically grown cells this resulted in l…
Myoglobin, expressed in brown adipose tissue of mice, regulates the content and activity of mitochondria and lipid droplets
2021
Abstract The identification of novel physiological regulators that stimulate energy expenditure through brown adipose tissue (BAT) activity in substrate catalysis is of utmost importance to understand and treat metabolic diseases. Myoglobin (MB), known to store or transport oxygen in heart and skeletal muscles, has recently been found to bind fatty acids with physiological constants in its oxygenated form (i.e., MBO2). Here, we investigated the in vivo effect of MB expression on BAT activity. In particular, we studied mitochondrial function and lipid metabolism as essential determinants of energy expenditure in this tissue. We show in a MB-null (MBko) mouse model that MB expression in BAT i…
Effect of tea consumption on oxidative stress and expression of DNA repair genes among metal press workers exposed to occupational noise
2020
Abstract Several studies have shown that tea consumption is associated with beneficial effects on human health, which is mainly explained by the antioxidant properties of tea. However, evidence on the effect of nutrition interventions on oxidative stress in an occupational setting is limited. Therefore, the present study aimed to investigate the effect of tea consumption on oxidative stress in noise-exposed metal press workers. The study sample comprised 24 metal press workers and 24 age-matched control subjects. Metal press workers were assigned to the intervention group consisting of a glass of jujube tea and a portion of raisins per day for 4 weeks. Full-shift noise dosimetry was perform…
Effects of pharmacological agents on the lifespan phenotype of Drosophila DJ-1beta mutants.
2010
Mutations in the DJ-1 gene cause autosomal recessive, early-onset Parkinsonism. The DJ-1 protein exerts a protective role against oxidative stress damage, working as a cellular oxidative stress sensor, and it seems to regulate gene expression at different levels. In Drosophila, two DJ-1 orthologs have been identified: DJ-1β and DJ-1β. Several studies have shown that loss of DJ-1β function causes Parkinson's disease (PD)-like phenotypes in flies such as age-dependent locomotor defects, reduced lifespan, and enhanced sensitivity to toxins that induce oxidative stress, like the herbicide paraquat. However, no dopaminergic neurodegeneration is observed. These results suggested that both locomot…
Hypothesis: can N-acetylcysteine be beneficial in Parkinson's disease?
1999
Based on the finding of decreased mitochondrial complex I activity in the substantia nigra of patients with Parkinson's disease, we propose that the consequent reduction of ATP synthesis and increased generation of reactive oxygen species may be a possible cause of nigrostriatal cell death. Since sulfhydryl groups are essential in oxidative phosphorylation, thiolic antioxidants may contribute to the preservation of these proteins against oxidative damage. In the present paper, we hypothesize that treatment with a sulfur-containing antioxidant such as N-acetylcysteine may provide a new neuroprotective therapeutic strategy for Parkinson's disease.
Current Experience in Testing Mitochondrial Nutrients in Disorders Featuring Oxidative Stress and Mitochondrial Dysfunction: Rational Design of Chemo…
2014
An extensive number of pathologies are associated with mitochondrial dysfunction (MDF) and oxidative stress (OS). Thus, mitochondrial cofactors termed "mitochondrial nutrients" (MN), such as alpha-lipoic acid (ALA), Coenzyme Q10 (CoQ10), and L-carnitine (CARN) (or its derivatives) have been tested in a number of clinical trials, and this review is focused on the use of MN-based clinical trials. The papers reporting on MN-based clinical trials were retrieved in MedLine up to July 2014, and evaluated for the following endpoints: (a) treated diseases; (b) dosages, number of enrolled patients and duration of treatment; (c) trial success for each MN or MN combinations as reported by authors. The…
Metabolomics in the diagnosis of sepsis
2014
IntroductionSepsis is an important cause of mortality and morbidityfor preterm and hospitalized newborn babies. Today, nosingle test satisfies the criteria as being the ideal markerfor the early diagnosis of neonatal sepsis. Analysis of theentire metabolome is a promising method for determin-ing metabolic variations correlated with sepsis [1-6].Metabolomics profiling and sepsisWorks on metabolomics concerning sepsis conductedon animals and humans of different ages (newborn andadults) have recently been published and are presentedin Table 1. In septic patients compared to controls (inplasma and urine) it is possible to observe an increaseof metabolites which are part of the oxidative metabo-…
Drugs modulating the biological effects of peroxynitrite and related nitrogen species
2006
The term “reactive nitrogen species” includes nitrogen monoxide, commonly called nitric oxide, and some other remarkable chemical entities (peroxynitrite, nitrosoperoxycarbonate, etc.) formed mostly from nitrogen monoxide itself in biological environments. Regardless of the specific mechanisms implicated in their effects, however, it is clear that an integrated pharmacological approach to peroxynitrite and related species is only just beginning to take shape. The array of affected chemical and pathological processes is extremely broad. One of the most conspicuous mechanisms observed thus far has been the scavenging of the peroxynitrite anion by molecules endowed with antioxidant activity. T…
New oxidative derivatives of atractyligenin and their cytotoxic activity
2006
ent-Kauranes are naturally occurring diterpenoids isolated from several families, such as Asteraceae and Lamiaceae. These compounds have attracted interest because of their structures and their biological activities as anti-tumorals, anti-HIV and anti-bacterials [1]. Extensive chemical work [2] was carried out on the structure of atractyligenin, the nor-diterpene aglycone of the glucoside atractyloside, occurring, together with its diterpene homologous carboxy-atractyloside, in the root of Atractylis gummifera L. (Compositae). The interest for these compounds was stimulated by the high toxicity [3] of both glucosides, responsible of many deadly poisoning in past time. Due to the 15-hydroxyl…
�ber die Wirkung von Metyrapon auf den mikrosomalen Arzneimittelabbau
1967
The inhibitor of adrenal steroid-11-β-hydroxylation, Metyrapone (SU 4885), also decreases the rate of drug hydroxylation reactions, both in vitro and in vivo. The follwing oxidative microsomal reactions were studied: O-demethylation of p-nitroanisole, N-demethylation of amidopyrine, and ring hydroxylation of acetanilide. In all three cases Metyrapone inhibits the formation of the reaction products. The inhibitor concentrations required for reduction of the initial reaction rates to one half are 7.5 · 10−4 M, 5 · 10−4m and 20 · 10−4 M, respectively. Steroid C-11-β-hydroxylation is reduced to one half by 2.5 · 10−4 M Metyrapone.