Search results for "Reductases"
showing 10 items of 276 documents
Effect of chronic exercise on glucose uptake and activities of glycolytic enzymes measured regionally in rat heart.
1989
Regional glucose uptake in perfused hearts, and the activities of several glycolytic enzymes contributing to the glucose metabolism in perfused and nonperfused hearts were studied in male and female rats after 8–9 weeks of swimming training. The left ventricular glucose uptake showed a transmural gradient in the sedentary animals, the subendocardial uptake being 30% and 12% higher than that of the subepicardial layer in the males and females, respectively. Swimming exercise abolished the left ventricular glucose uptake gradient in male rats, and in female rats an opposite gradient was found, the subepicardial uptake being 23% higher than the subendocardial uptake. The activities of phosphof…
Mitochondrial myopathy with lactic acidosis and deficient activity of muscle succinate cytochrome-c-oxidoreductase
1984
A male infant had severe muscular hypotonia from birth. Recurrent vomiting with dehydration and severe metabolic acidosis complicated the course. Elevated lactate (up to 12.3 mmol/l; n less than 2), pyruvate (0.4 mmol/l; n less than 0.05) and alanine levels were found in serum with an abnormal lactate/pyruvate ratio (greater than 30; n less than 15). In urine the concentrations of lactate, pyruvate, alanine and of several intermediates of the citric acid cycle were increased. In muscle, numerous disseminated "ragged red fibres" were found by light microscopy; muscle fibres were found to contain subsarcolemmal aggregates of mitochondria, lipid droplets and glycogen by electromicroscopical me…
Delayed effects of ciprofibrate on rat liver peroxisomal properties and proto-oncogene expression.
1995
Peroxisome proliferators (PPs) are non-genotoxic carcinogens in rodents. Their reversible effects on rat liver have been studied with ciprofibrate and fenofibrate. We found that with the hypolipemic drug fenofibrate a pause of 28 days is sufficient for a return to normal status, whereas with the highly potent PP ciprofibrate, the stimulation of ACO mRNA levels remains after its withdrawal. We investigated the effects of the renewal of the treatment with PPs on other peroxisomal parameters and proto-oncogene expression using Wistar rats. Interestingly, c-myc expression was enhanced even upon drug withdrawal, and was more stimulated by the second exposure to ciprofibrate, while c-fos expressi…
Dexamethasone upregulates Nox1 expression in vascular smooth muscle cells.
2014
<b><i>Background/Aim:</i></b> It has been demonstrated that dexamethasone-induced hypertension can be prevented by the NADPH oxidase inhibitor apocynin. The effect of dexamethasone on NADPH oxidase, however, is unknown. The present study was conducted to investigate the effect of dexamethasone on the gene expression of Nox1, the major NADPH oxidase isoform in vascular smooth muscle cells. <b><i>Results:</i></b> Oral treatment of Wistar-Kyoto rats with dexamethasone (0.03 mg/kg/day) for 12 days led to an upregulation of Nox1 mRNA expression in the aorta. In cultured A7r5 rat aortic smooth muscle cells, dexamethasone increased Nox1 mRNA expressi…
Differential effects of diabetes on the expression of the gp91phox homologues nox1 and nox4.
2004
The nox2-dependent NADPH oxidase was shown to be a major superoxide source in vascular disease, including diabetes. Smooth muscle cells of large arteries lack the phagocytic gp91phox subunit of the enzyme; however, two homologues have been identified in these cells, nox1 and nox4. It remained to be established whether also increases in protein levels of the nonphagocytic NADPH oxidase contribute to increased superoxide formation in diabetic vessels. To investigate changes in the expression of these homologues, we measured their expression in aortic vessels of type I diabetic rats. Eight weeks after streptozotocin treatment, we found a doubling in nox1 protein expression, while the expressio…
The CO-releasing molecule CORM-2 is a novel regulator of the inflammatory process in osteoarthritic chondrocytes
2008
Previous work has shown that the CO-releasing molecule CORM-2 protects against cartilage degradation. The aim of this study was to examine whether CORM-2 can control the production of inflammatory mediators in osteoarthritic chondrocytes and determine the mechanisms involved.Primary cultures of chondrocytes from OA patients were stimulated with IL-1beta. The production of reactive oxygen species, nitrite, PGE(2), TNF-alpha and IL-1 receptor antagonist (IL-1Ra) were measured in the presence or absence of CORM-2. The expression of nitric oxide synthase-2 (NOS-2), cyclo-oxygenase-2 (COX-2) and microsomal PG E synthase-1 (mPGES-1) was followed by western blot and real-time PCR. Activation of nu…
Anti-proliferative and pro-apoptotic activities of hydroxytyrosol on different tumour cells: the role of extracellular production of hydrogen peroxide
2011
Several recently published data suggest that the anti-proliferative and pro-apoptotic properties of hydroxytyrosol [3,4-dihydroxyphenyl ethanol (3,4-DHPEA)] on HL60 cells may be mediated by the accumulation of hydrogen peroxide (H2O2) in the culture medium. The aim of this study was to clarify the role played by H2O2 in the chemopreventive activities of 3,4-DHPEA on breast (MDA and MCF-7), prostate (LNCap and PC3) and colon (SW480 and HCT116) cancer cell lines and to investigate the effects of cell culture medium components and the possible mechanisms at the basis of the H2O2-producing properties of 3,4-DHPEA. The proliferation was measured by the MTT assay and the apoptosis by both fluores…
The Low Energy-Coupling Respiration in Zymomonas mobilis Accelerates Flux in the Entner-Doudoroff Pathway.
2015
Performing oxidative phosphorylation is the primary role of respiratory chain both in bacteria and eukaryotes. Yet, the branched respiratory chains of prokaryotes contain alternative, low energy-coupling electron pathways, which serve for functions other than oxidative ATP generation (like those of respiratory protection, adaptation to low-oxygen media, redox balancing, etc.), some of which are still poorly understood. We here demonstrate that withdrawal of reducing equivalents by the energetically uncoupled respiratory chain of the bacterium Zymomonas mobilis accelerates its fermentative catabolism, increasing the glucose consumption rate. This is in contrast to what has been observed in o…
Quantification of denitrifying bacteria in soils by nirK gene targeted real-time PCR.
2004
Abstract Denitrification, the reduction of nitrate to nitrous oxide or dinitrogen, is the major biological mechanism by which fixed nitrogen returns to the atmosphere from soil and water. Microorganisms capable of denitrification are widely distributed in the environment but little is known about their abundance since quantification is performed using fastidious and time-consuming MPN-based approaches. We used real-time PCR to quantify the denitrifying nitrite reductase gene (nirK), a key enzyme of the denitrifying pathway catalyzing the reduction of soluble nitrogen oxide to gaseous form. The real-time PCR assay was linear over 7 orders of magnitude and sensitive down to 102 copies by assa…
Denitrification in pathogenic bacteria : for better or worst ?
2005
A large variety of physiological and taxonomic groups have the ability to use nitrogen oxides as alternative electron acceptors. Brucella spp. is an alpha-proteobacteriaceae that induces a persistent disease in some mammals. Recent work has revealed that a denitrifying gene cluster is important in the interaction of Brucella neotomoae with its host.