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

The purpose of this study was to measure the effects of a 10 week training, 3 week detraining cycle upon heart, muscle and adipose tissue of the rat. Specific pathogen-free female Wistar rats, 175 g at the onset of the experiments, were separated into three treatment groups; Sedentary Control (SC), Trained (T) and Detrained (DT). Animals from the T group were killed at 2, 4, 6, 8 and 10 weeks and animals from the DT group were killed at 7, 14 and 21 days after the last day of training. Unweighted swimming--6 h/day, 5 day/week, was the form of training employed. The animals, after being sacrificed, were anesthetized with nembutal (45 mg/kg body wt.) and muscle samples and heart removed. These tissues were frozen and analyzed at a later date for succinate dehydrogenase (SDH) activity (muscles), total protein (TP), total hydroxylprotein (TH) and wet and dry weight (heart). Adipose tissue was removed last, digested in collagenase (5 mg/ml) and the isolated cells used to measured 2-[3H]deoxyglucose uptake (DOG) and the conversion of D-[1-14C]glucose (C-1) and D-[6-14C]glucose (C-6) to CO2. The results of this study show that 10 weeks of endurance training induced myocardial hypertrophy (P less than 0.05) which involved increases in both TP and TH, the heart of the trained animals having 20.8% more protein and a 28.5% more hydroxlprotein than the sedentary controls. With detraining hypertrophy was lost within 21 days. Training maintained fat cell size at its pre-trained diameter, while inactivity allowed growth in the adipocytes of the control animals. The uptake of DOG and the conversion of glucose C-1 and glucose C-6 to CO2, were significantly (P less than 0.05) higher in the adipocytes of trained animals indicating that they were more responsive to insulin than the sedentary controls, which corresponded to increases in the respiratory enzyme levels of the muscles. During the first 7 days of detraining DOG uptake and both C-1 and C-6 glucose oxidation remained elevated. In conclusion the results of this study clearly demonstrate that there is a direct relationship between adiposity and training that can be related to the insulin responsiveness of the adipose tissue.
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PMID:The influence of training-detraining upon the heart, muscle and adipose tissue of female rats. 182 61

Hepatic dysfunction caused by oxidative stress when secondary peroxidation products were administered orally was investigated in rat. In serum at 24 hr after the administration of secondary products, the contents of lipid peroxides reached a maximum, the level of tocopherol reached a minimum, and the transaminase activities were elevated. In the liver, the lipid peroxide contents were kept high between 6 and 24 hr and tocopherol level was kept low between 15 and 48 hr after the does. Therefore, the hepatic oxidative stress was most severe around 15 hr after the dose. Dysfunction in the liver having oxidative stress was then made clear. One was a disturbance in synthetic system of glucose 6-phosphate. The decreases in activities of phosphoglucomutase and glucokinase reduced a level of glucose 6-phosphate, which suppressed the supply of NADPH in pentose cycle, while the NADPH was consuming well for detoxification of endogenous lipid peroxides. Another was specific inactivations of mitochondrial succinate dehydrogenase and aldehyde dehydrogenase. A third was the depletion of CoASH, which induced the decreases in activities of citrate cycle and lipogenesis. The other was a formation of lipofuscin. Even after the liver was recovering from the oxidative stress, the liver was getting hypertrophy and lipofuscin was accumulating. To make the cause of hepatic dysfunction clear, it was examined whether the incorporated secondary products in the liver could directly attack the enzymes or not. A reasonable amount of secondary products present in the liver was estimated, and then the amount of secondary products was added in hepatic subcellular organelles in vitro. It was found that mitochondrial NAD-dependent aldehyde dehydrogenase, glucokinase, and CoASH were directly attacked and inactivated by the incorporated secondary products in the liver. Thus, a part of dietary secondary products was incorporated into liver, and was not detoxified, but injured the enzymes and CoASH. Then it resulted in lipofuscin formation.
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PMID:Hepatotoxicity caused by dietary secondary products originating from lipid peroxidation. 183 11

Enzyme histochemical profiles of spinal motoneurons in the zebrafish were determined. Five enzymes of glucose metabolism were chosen: glucose-6-phosphate dehydrogenase (G6PDH), hexokinase (HK), phosphofructokinase (PFK), succinate dehydrogenase (SDH) and NADH tetrazolium reductase (NADH-TR). Motoneurons were traced with Fluorogold and classified as those that innervate white muscle fibres (W-MNs) and those that innervate red and intermediate muscle fibres (R/I-MNs). The average enzyme activities per volume of tissue in the somata of both populations differed at most by 25%. Both the average soma volume and the average number of muscle fibres innervated are three times larger for the W-MNs than for the R/I-MNs. This suggests that the total amount of enzyme activity within a neuron soma matches target size. In the R/I-MNs, the activities of SDH and NADH-TR were closely correlated (correlation coefficient, r = 0.99; p less than 0.05) and HK activity correlated well with G6PDH activity (r = 0.94; p less than 0.05), but not with PFK (r = 0.64; p greater than 0.05). In the W-MNs, there was no correlation between SDH and NADH-TR (r = -0.59; p greater than 0.05) or between HK and G6PDH (r = 0.50; p greater than 0.05) and the correlation coefficient between HK and PFK activity was close to zero (r = 0.04; p greater than 0.05). It was concluded that in the R/I-MNs, which are continuously active, firing activity is fuelled by oxidative metabolism. We suggest that in the W-MNs glucose is stored in the form of glycogen and that, despite high levels of NADH-TR present, the energy for intermittent firing activity is provided by glycolysis.
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PMID:Histochemical profiles of motoneurons innervating muscle fibres with different activity patterns in the zebrafish, Brachydanio rerio. 183 17

A short-term training program involving 2 h of daily exercise at 59% of peak O2 uptake (VO2max) repeated for 10-12 consecutive days was employed to determine the significance of adaptations in energy metabolic potential on alterations in energy metabolism and substrate utilization in working muscle. The initial VO2max determined before training on the eight male subjects was 53.0 +/- 2.0 (SE) ml.kg-1.min-1. Analysis of samples obtained by needle biopsy from the vastus lateralis muscle before exercise (0 min) and at 15, 60, and 99 min of exercise indicated that on the average training resulted (P less than 0.05) in a 6.5% higher concentration of creatine phosphate, a 9.9% lower concentration of creatine, and a 39% lower concentration of lactate. Training had no effect on ATP concentration. These adaptations were also accompanied by a reduction in the utilization in glycogen such that by the end of exercise glycogen concentration was 47.1% higher in the trained muscle. Analysis of the maximal activities of representative enzymes of different metabolic pathways and segments indicated no change in potential in the citric acid cycle (succinate dehydrogenase, citrate synthase), beta-oxidation (3-hydroxyacyl CoA dehydrogenase), glucose phosphorylation (hexokinase), or potential for glycogenolysis (phosphorylase) and glycolysis (pyruvate kinase, phosphofructokinase, alpha-glycerophosphate dehydrogenase, lactate dehydrogenase). With the exception of increases in the capillary-to-fiber area ratio in type IIa fibers, no change was found in any fiber type (types I, IIa, and IIb) for area, number of capillaries, capillary-to-fiber area ratio, or oxidative potential with training.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Early muscular and metabolic adaptations to prolonged exercise training in humans. 186 84

A rapid switch from a fermentative to a primarily oxidative type of glucose utilization was observed during in vitro differentiation of Trypanosoma brucei STIB348 and EATRO1244 bloodstream to procyclic trypomastigotes. In accordance with previously published reports bloodstream populations produced pyruvate as the major end product of glucose catabolism, together with very small amounts of CO2, succinate and glycerol. During differentiation pyruvate excretion decreased within 48 h to the low levels produced by 28-day procyclic stages. Concomitant with the decline in pyruvate formation, acetate appeared as a new product and the rates of respiratory CO2 increased considerably. The amount of carbon released with these compounds could account for nearly all of the glucose carbon consumed. Rates of glucose utilization and formation of acetate and CO2 in cells differentiated for 48 h were essentially the same as those found in 28-day procyclics. Succinate and glycerol excretion remained low during the entire transformation process, and no significant difference in the pattern and quantities of end products were found between the two trypanosome strains. During trypanosome differentiation the changes in metabolism were associated with marked alterations in enzyme activity levels. Activities of the tricarboxylic acid (TCA) cycle enzymes citrate synthase, isocitrate dehydrogenase (NAD+), succinate dehydrogenase and fumarase were not detectable in bloodstream trypomastigotes but appeared upon differentiation for 24 h. An exception was citrate synthase whose activity was not demonstrable until 48 h postinoculation into culture. After 48 h the majority of the TCA cycle enzyme activities continued to increase steadily until day 28. Pyruvate kinase activity decreased in differentiating cells after 48 h to about 25% of the level found in bloodstream trypomastigotes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Alterations in Krebs cycle enzyme activities and carbohydrate catabolism in two strains of Trypanosoma brucei during in vitro differentiation of their bloodstream to procyclic stages. 190 88

To establish the difference of mechanism between irritative and paralytic nystagmus, alterations of Na-K-ATPase and succinic dehydrogenase activity in the vestibular sensorineural elements were investigated for 20 guinea pigs, and glucose uptake of the vestibular nuclei for 13 guinea pigs were measured by the [14C]-2-deoxy-D-glucose method. Irritative and paralytic nystagmus were experimentally provoked by introducing K+ into the perilymphatic space. From the results it was concluded that irritative nystagmus is provoked by increased excitability of vestibular sensory cells, while paralytic nystagmus is provoked by decreased excitability. However, the direction of nystagmus was eventually decided by the tonus imbalance between the bilateral vestibular nuclei. The ipsilateral vestibular nucleus was predominant during irritative nystagmus, while the contralateral vestibular nucleus was predominant during paralytic nystagmus.
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PMID:The mechanism of irritative nystagmus and paralytic nystagmus. A histochemical study of the guinea pig's vestibular organ and an autoradiographic study of the vestibular nuclei. 192 91

Ginseng polysaccharides (GH1) 50-200 mg/kg ip or sc reduced blood glucose and liver glycogen of mice. Adrenalectomy did not affect this action. GH1 increased the content of pyruvic acid, but decreased the content of lactic acid by weakening the activity of lactate dehydrogenase. GH1 accelerated oxidative-phosphorylation of carbohydrate since the activities of succinate dehydrogenase (SDH) and cytochrome oxidase (CCO) were obviously stimulated. Besides the promotion of the activity of SDH in human embryonic lung fibroblasts (HELF), GH1 decreased the content of polysaccharides in HELF of the 24th age generation, but increased that of the 40th age generation. On the other hand, GH1 stimulated the release of insulin. It is suggested that the reduction of blood glucose and liver glycogen induced by GH1 be primarily due to the increase of carbohydrate utilization and the decrease of glycogenesis.
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PMID:[Effects of ginseng polysaccharides on reducing blood glucose and liver glycogen]. 196 54

Isolation and culture techniques for hepatocytes from whole livers of the cynomolgus monkey, Macaca fascicularis, are described. Hepatocytes were isolated by two-step perfusion of livers, using collagenase with hyaluronidase; fructose and trypsin inhibitor were included to reduce cell loss. Yields from a single liver average 4 X 10(9) cells with viabilities of 90.8 +/- 5.7%. Cells, plated on collagen substrates, were assessed for changes in morphology and various marker enzyme activities over a period of 7 d in culture. Cells exhibited a morphology similar to that observed for this species in vivo; little change in attached and spread cells was observed over the length of time monitored. Enzyme activities for catalase, succinate dehydrogenase, and tyrosine aminotransferase were observed to decrease significantly (though considerable activity remained), whereas acid phosphatase and 5'-nucleotide phosphodiesterase remained unchanged. Activity of cytochrome P-450 reductase was observed to increase slightly for the first 2 d, then decrease to about 60% of initial levels. Activity of alpha-mannosidase was stable for 4 d but was observed to be increased at Day 7. Cells were observed to retain metabolic responsiveness, demonstrated by glucose production by both gluconeogenesis and glycogenolysis in response to glucagon stimulation. The monkey hepatocytes obtained by methods described here thus retain hepatocellular morphology and activity through at least 1 wk in culture without medium or culture modification.
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PMID:Isolation and culture of hepatocytes from the cynomolgus monkey (Macaca fascicularis). 197 77

The activity of the mitochondrial glycerol phosphate dehydrogenase (EC 1.1.99.5), the enzyme unique to the glycerol phosphate hydrogen shuttle, was measured in normal human tissues and tumors and compared with the activity of succinate dehydrogenase, another enzyme that transfers electrons to ubiquinone at site II of the electron transport chain. Six of 7 insulinomas and 10 of 12 carcinoid tumors showed high glycerol phosphate dehydrogenase activity. The activity was also increased in 3 of 4 gastrinomas, 2 paraganglionomas, 1 of 4 thyroid nodules, and 1 parathyroid tumor. These tissues belong to the amine precursor uptake decarboxylation system. The activity of glycerol phosphate dehydrogenase was generally unremarkable in non-amine precursor uptake decarboxylation system tumors and in normal tissues studied. However, 1 of 2 breast carcinomas, 1 submandibular tumor, and 2 of 3 melanomas were enriched in glycerol phosphate dehydrogenase activity. In general, succinate dehydrogenase activity exceeded that of glycerol phosphate dehydrogenase in all tissues except some of the tissues in which glycerol phosphate dehydrogenase activity was high. Normal tissues, such as the pancreatic beta-cell, which aerobically metabolize glucose rapidly utilize the glycerol phosphate shuttle to oxidize the large amount of NADH formed from glucose metabolism in the cytosol. Whether this is the reason for the enriched activity of the glycerol phosphate dehydrogenase in certain amine precursor uptake decarboxylation system tumors is unknown.
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PMID:High activity of mitochondrial glycerol phosphate dehydrogenase in insulinomas and carcinoid and other tumors of the amine precursor uptake decarboxylation system. 197 16

Thioacetamide (100 mg/kg), when administered to normal rats, caused a significant increase in the activities of 5'-nucleotidase and gamma-glutamyl transpeptidase and a decrease in the activities of glucose 6-phosphatase and succinate dehydrogenase enzymes in the liver. DNA, RNA, and proteins were increased while the cytochrome P450 in the microsomal fraction and the glycogen content in the liver were decreased significantly. Elevations in the activities of GOT, GPT, and alkaline phosphatase and bilirubin content in serum were also observed. Picroliv, a standardised glycoside fraction of Picrorhiza kurroa, in doses of 12.5 and 25 mg/kg prevented most of the biochemical changes induced by thioacetamide in liver and serum. The hepatoprotective activity of Picroliv was comparable with that of silymarin, a known hepatoprotective agent obtained from seeds of Silybum marianum.
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PMID:Picroliv affords protection against thioacetamide-induced hepatic damage in rats. 206 53


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