Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Trypanosoma brucei procyclic trypomastigotes were made permeable by using digitonin (0-70 micrograms/mg of protein). This procedure allowed exposure of coupled mitochondria to different substrates. Only succinate and glycerol phosphate (but not NADH-dependent substrates) were capable of stimulating oxygen consumption. Fluorescence studies on intact cells indicated that addition of succinate stimulates NAD(P)H oxidation, contrary to what happens in mammalian mitochondria. Addition of malonate, an inhibitor of succinate dehydrogenase, stimulated NAD(P)H reduction. Malonate also inhibited intact-cell respiration and motility, both of which were restored by further addition of succinate. Experiments carried out with isolated mitochondrial membranes showed that, although the electron transfer from succinate to cytochrome c was inhibitable by antimycin, NADH-cytochrome c reductase was antimycin-insensitive. We postulate that the NADH-ubiquinone segment of the respiratory chain is replaced by NADH-fumarate reductase, which reoxidizes the mitochondrial NADH and in turn generates succinate for the respiratory chain. This hypothesis is further supported by the inhibitory effect on cell growth and respiration of 3-methoxyphenylacetic acid, an inhibitor of the NADH-fumarate reductase of T. brucei.
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PMID:The role of succinate in the respiratory chain of Trypanosoma brucei procyclic trypomastigotes. 271 53

Cold adapted rats are shown to have glucose and fatty acids concentration in blood inchanged, lactate concentration increased and triglyceride concentration decreased against the control level. Glucose utilization rate in the tolerance test grows. Glycogen content falls, hexokinase and succinate dehydrogenase activity increases, glucose-6-phosphatase and NAD+-isocytratedehydrogenase activity decreases in the liver of experimental animals. The results indicate that utilization of carbohydrate and lipid substrates for thermogenesis is intensified in cold-adapted rats. The hypothesis is supported by the data of tests dealing with IPNA injection or with bringing the animals back under thermocomfortable conditions.
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PMID:[Carbohydrate and lipid metabolism in rats during adaptation to cold]. 272 45

Early iron deficiency in rat does not affect the weight or the protein, DNA, and RNA content but results in a slight reduction in gamma-aminobutyric acid (GABA) (13%, p less than 0.01) and glutamic acid (20%, p less than 0.001) content of the brain. The activities of the two GABA shunt enzymes, glutamate dehydrogenase and GABA-transaminase, and of the NAD+-linked isocitrate dehydrogenase (ICDH) were inhibited whereas the glutamic acid decarboxylase, mitochondrial NADP+-linked ICDH, and succinic dehydrogenase activities remained unaltered in brain. On rehabilitation with the iron-supplemented diet for 1 week, these decreased enzyme activities in brain attained the corresponding control values. However, the hepatic nonheme iron content increased to about 80% of the control, after rehabilitation for 2 weeks. A prolonged iron deficiency resulting in decreased levels of glutamate and GABA may lead to endocrinological, neurological, and behavioral alterations.
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PMID:Effect of early iron deficiency in rat on the gamma-aminobutyric acid shunt in brain. 287 Nov 28

Mitochondrial enzymes and respiration were studied in the hearts of mice exposed to ethanol in utero from gestational Day 8 to parturition. This treatment had previously been shown by electron microscopy to result in myofibril loss and mitochondrial abnormalities. Ethanol was administered to pregnant mice by a liquid diet paradigm and pair-fed dams were used as controls. Ethanol exposure in utero reduced the activities of two mitochondrial inner membrane enzymes, cytochrome c oxidase and succinate dehydrogenase, in the hearts of perinatal mice. Secondly, mitochondrial respiration under both State 3 and 4 conditions with a NAD-linked substrate was depressed in the hearts obtained from the ethanol-exposed fetal mice. However, when a flavin-linked substrate was used, State 3 (ADP-stimulated) but not State 4 respiration was depressed. This study illustrates that in utero exposure to ethanol is deleterious to the functioning of cardiac mitochondria in newborn mice, which in turn could contribute to the development of the heart pathologies present in the Fetal Alcohol Syndrome.
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PMID:Cardiac mitochondrial abnormalities in a mouse model of the fetal alcohol syndrome. 289 3

1. The succinate dehydrogenase (SDH) and D-3-hydroxybutyrate dehydrogenase (HBDH) activities were measured over a 24-hr period in rat liver mitochondria after chronic alcohol ingestion and withdrawal. 2. The diurnal patterns of both the enzyme activities were shown to change after alcohol consumption, with 64-66% decrease in the daily mean levels. 3. The diurnal rhythms of the SDH and HBDH activities are partially restored 24-72 hr after alcohol withdrawal. 4. There was no correlation between changes in both the enzyme activities and the NAD+/NADH ratio of liver mitochondria from control, ethanol-fed and withdrawn rats over the day.
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PMID:Diurnal changes in succinate and D-3-hydroxybutyrate dehydrogenase activities of rat liver mitochondria after chronic alcohol consumption and withdrawal. 290 76

In order to elucidate the problem of which cells are involved in calcium transport and to estimate the role of mitochondria in calcium transport in the avian shell gland, the fine structure and the Ca-ATPase, succinate dehydrogenase (SDH) and nicotinamide adenine dinucleotide (NAD+)-dependent isocitrate dehydrogenase (NAD+-ICDH) activity of the shell gland of egg-laying Japanese quails were examined. The surface epithelial cells, consisting of ciliated cells with cilia and microvilli and non-ciliated cells with microvilli, had many large and electron-dense granules. The tubular-gland cells occupied the proprial layer and lacked secretory granules. When an egg was in the shell gland, the well-developed mitochondria of tubular-gland cells characteristically tended to accumulate in the apical cytoplasm, while they were scattered throughout the cytoplasm when an egg was not in the shell gland. Intense Ca-ATPase activity was found on the microvilli of tubular-gland cells, and moderate activity was found on the lateral-cell surface. In the surface epithelial cells, the basolateral cell surface showed moderate enzymatic activity. Both SDH and NAD+-ICDH activity were found in tubular-gland cells when an egg was in the shell gland. These results strongly suggest that calcium for eggshell calcification is actively transported by the tubular-gland (depending on Ca-ATPase activity) and that the mitochondria of gland cells may play an important role in this process as an energy source.
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PMID:Histochemical studies of Ca-ATPase, succinate and NAD+-dependent isocitrate dehydrogenases in the shell gland of laying Japanese quails: with special reference to calcium-transporting cells. 293 10

The lead method for the histochemical demonstration of presumptive mitochondrial adenosinetriphosphatase was applied to biopsy and autopsy samples of the human vastus lateralis muscle. The effect of p-chloromercuribenzoate and of Triton X-100 was tested microdensitometrically and the activity of 'mitochondrial' ATPase was compared to the activity of enzymes of the oxidative metabolism succinic dehydrogenase and NAD-tetrazolium reductase. It is concluded that the ATPase activity displayed is not mainly mitochondrial. In autopsy material, it seems to be predominantly myofibrillar.
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PMID:The nonspecificity of the lead method for the histochemical demonstration of adenosine triphosphatases in human skeletal muscle fibres. 293 78

The morphology of the intestinal wall and the activity of certain mucosal enzyme systems in the course of neomycin treatment were evaluated. Conventional and, to study the role of the bacterial flora, germ-free rats received 500 mg neomycin daily by stomach tube. Rats were sacrificed after seven days and small intestine (proximal and distal part) together with segments of the colon were removed and prepared for histochemistry. The colon and proximal small intestine of untreated conventional and germ-free animals did not show appreciable differences in staining activity after treatment with neomycin. Neomycin diminished both in normal and germ-free rats the activity of NAD tetrazolium reductase, succinate dehydrogenase, esterase, alkaline phosphatase and acid phosphatase in the distal small intestine. The findings of this study indicate that explanations for the beneficial effects of neomycin on hyperammonemia in liver disease should not only include the bactericidal action of neomycin but also its influence on absorption and metabolic functions of the mucosal cells.
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PMID:Morphological effects of high dose neomycin sulphate on the small and large intestine. 296 22

Acute cooling of rats led to stimulation of NAD+-dependent isocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH) and NAD(P)+-transhydrogenase (TH) but did not affect the NADP+-ICDH activity in liver, heart and skeletal muscle mitochondria. After pretreatment of the animals with propranolol the stimulating effect was decreased, thus suggesting that endogenous catecholamines and beta-adrenoreceptors are of importance in activation of NAD+-ICDH, SDH and TH. The effects of cooling, noradrenaline and cAMP did not summarize. Role of catecholamines in stimulation of mitochondrial oxidative enzymes under conditions of cooling is discussed.
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PMID:[Stimulation of mitochondrial oxidative enzymes in acute cooling and its catecholamine mechanisms]. 302 85

In the present study the effects of chronic administration of dextroamphetamine on energy metabolism in the brain of the rat were examined. The enzymes studied were: hexokinase (soluble and particulate forms), phosphofructokinase, pyruvate kinase, lactate dehydrogenase, citrate synthase, NAD+ and NADP+-dependent isocitrate dehydrogenases, succinate dehydrogenase and malate dehydrogenase. All the activities of the enzymes were assayed in four regions of the brain of the rat (cerebellum, medulla oblongata and pons, cererbral cortex and diencephalon). Rats were injected intaperitoneally once daily with dextroamphetamine for 20 consecutive days. The initial dose was 5 mg/kg/day and the dose was then increased by 1 mg/kg/every 5 days up to a total of 8 mg/kg/day on days 16-20. In the glycolytic enzymes a reduction of the activity of phosphofructokinase was found in the diencephalon and an increase of the activity of pyruvate kinase and lactate dehydrogenase in the diencephalon and medulla oblongata and pons, respectively. Citrate synthase was the only enzyme in the Krebs' cycle affected by chronic administration of dextroamphetamine. The results presented here show that chronic administration of dextroamphetamine produced important changes in some enzymes of glycolysis and the Krebs' cycle in the brain of the rat.
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PMID:Effects of chronic administration of dextroamphetamine on enzymes of energy metabolism in regions of the rat brain. 303 25


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