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)

Exercise training improves maximal oxygen uptake and endurance times in adult human beings and other animals. The mechanism of this improvement results in part from anabolic effects of exercise and may be mediated by growth hormone (GH). Little is known about the role of GH in the adaptation to exercise in younger, still-developing organisms. To examine this role, we began a 4-wk treadmill exercise training protocol in 14-d-old female rats. GH was suppressed by passive immunization with anti-GH releasing hormone antisera. There were four experimental groups: 1) GH-control (normal GH secretory capacity), untrained (n = 21); 2) GH-suppressed, untrained (n = 13); 3) GH-control, trained (n = 14); and 4) GH-suppressed; trained (n = 11). At the end of the training period, maximal oxygen uptake and treadmill endurance running time were measured. Serum GH and IGF-I were assessed using RIA, and whole hind limb musculature succinate dehydrogenase (an indicator of mitochondrial function) was measured with standard fluorometric technique. Body weight gain was markedly reduced in GH-suppressed rats (mean, 54% of GH-controls in untrained rats and 55% in trained; p < 0.05). No apparent effect of training on linear growth was observed. As expected, serum IGF-I was markedly reduced by GH suppression, but no exercise-induced increase occurred in IGF-I as a result of training in either the GH-control or GH-suppressed rats. In GH-control rats, maximal oxygen uptake and succinate dehydrogenase were 69% and 25% greater, respectively, in trained compared with untrained rats (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of growth hormone suppression on exercise training and growth responses in young rats. 816 58

The objectives of the present study were to determine the size and enzyme properties of soleus fibers of rats subjected to a 4-day spaceflight (National Aeronautics and Space Administration, STS-41) and the effects of exogenous growth hormone (GH) on the atrophic response of the muscle. Four groups of rats were studied: 1) control (Con), 2) Con plus GH treated (Con + GH), 3) flight (Fl), and 4) F1 plus GH treated (Fl + GH). Cross-sectional area and the activities of succinate dehydrogenase and myofibrillar adenosinetriphosphatase (ATPase) were determined in fibers identified in frozen serial cross sections. Fibers were categorized immunohistochemically as slow, fast, or slow-fast on the basis of their reaction with slow and fast myosin heavy-chain (MHC) monoclonal antibodies. Fibers also were categorized as light or dark on the basis of their staining for ATPase at pH 8.6. After the 4-day flight, mean body weight was significantly decreased compared with control. The absolute and relative (muscle wt/body wt) soleus weights were significantly smaller in the Fl and Fl + GH rats compared with their respective ground-based controls. In both flight groups, the cross-sectional area of the light ATPase fibers was significantly smaller (approximately 30%) than control. Three of 11 flight rats had a higher proportion of fibers expressing both slow and fast MHCs than expected on the basis of the fiber type distribution in the 11 control rats. Mean fiber succinate dehydrogenase and ATPase activities were similar among the four groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Absence of a growth hormone effect on rat soleus atrophy during a 4-day spaceflight. 845 66

Iron-responsive elements (IREs) are cis-acting mRNA stem-loop structures that specifically bind cytoplasmic iron regulatory proteins (IRPs). IRP-IRE interactions mediate the coordinate post-transcriptional regulation of key proteins in iron metabolism, such as ferritin, transferrin receptor, and erythroid 5-aminolevulinic acid synthase. Depending on whether the IRE is located in the 5'- or 3'-untranslated region (UTR), binding of IRP will inhibit mRNA translation or degradation, respectively. Here we describe a new IRE in the 5'-UTR of succinate dehydrogenase subunit b (SDHb) mRNA of Drosophila melanogaster. The SDHb IRE binds in vitro to vertebrate and insect IRPs with a high affinity equal to that of human ferritin H chain IRE. Under conditions of iron deprivation, SDHb mRNA of Drosophila SL-2 cells shifts to a non-polysome-bound pool. Moreover, translation of a human growth hormone mRNA with the SDHb IRE in its 5'-UTR is iron-dependent in stably transfected L cells. We conclude that the SDHb IRE mediates translational inhibition both in insect and vertebrate cells. This constitutes the first identification of a functional IRE in insects. Furthermore, Drosophila SDHb represents the second example, after porcine mitochondrial aconitase, of an enzyme of the citric acid cycle whose mRNA possesses all necessary features for translational regulation by cellular iron levels.
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PMID:Succinate dehydrogenase b mRNA of Drosophila melanogaster has a functional iron-responsive element in its 5'-untranslated region. 853 May 20

Enlargement of nuclear volume of the neurosecretory cells producing growth hormone (light green cells of cerebral ganglia) was observed in experimentally infected snails. In addition to noted earlier increase in the amounts of: neurosecretory material, RNA and the loose fraction of nuclear chromatin in the perikarya, it can be the next argument for the influence of the parasite on the activity of the hormonal system cells of its intermediate host. Found in infected individuals, the increase in the succinate dehydrogenase activity in these perikarya, in the absence of changes in their morphology (which are an indications of the release of the adaptative type of cellular response), indicates that examined cells supply their energy need in the way of aerobic metabolism reactions. This increase in their activity is in the range of physiological standard.
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PMID:[Investigations on the pathogenesis of changes in somatic growth of Lymnaea stagnalis (Gastropoda:Pulmonata) experimentally infected with parthenites of trematode Opisthioglyphe ranae (Digenea:Plagiorchiida). II. Karyometry and aerobic metabolism of the neurosecretory cells]. 896 76

Resistance to the anabolic effects of growth hormone (GH) occurs with severe caloric deficit. This study examined whether moderate caloric deficit (50% of daily intake for 7 days) in the adolescent rat exceeds a critical threshold for GH action and whether a combination of GH and insulin-like growth factor I (IGF-I) would have enhanced anabolic effects on the diaphragm (Dia). Five groups of rats (4 wk old) were studied: 1) control (Ctl), 2) nutritionally deprived (ND), 3) ND + GH, 4) ND + IGF-I, and 5) ND + GH + IGF-I. IGF-I was given by continuous infusion (200 microg/day). GH was injected subcutaneously (250 microg every 12 h). Contractile and fatigue properties of the Dia were determined in vitro. Quantitative histochemical methods were used to determine Dia fiber type proportions, cross-sectional areas, and succinate dehydrogenase activities. The body weight of Ctl rats increased 46% compared with 7% in ND animals, whereas that of ND rats receiving growth factors was intermediate. Serum IGF-I levels were reduced 54% in ND animals and maintained with the provision of growth factors. Dia fatigue resistance was improved in ND animals receiving growth factors. There were no differences in Dia contractile properties, fiber type proportions, or succinate dehydrogenase activities across groups. ND resulted in atrophy/growth arrest of all Dia fibers (20-32%) compared with Ctl. Administration of IGF-I and/or GH completely prevented atrophy/growth arrest of all Dia fibers. No additive or synergistic effects were noted. We propose that these growth factors may provide useful short-term adjunctive nutritional support in circumstances in which the provision of optimal nutrition may be delayed or inadequate.
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PMID:IGF-I and/or growth hormone preserve diaphragm fiber size with moderate malnutrition. 965 74

The purpose of this study was to investigate the effect of concurrent strength and endurance training on strength, endurance, endocrine status and muscle fibre properties. A total of 45 male and female subjects were randomly assigned to one of four groups; strength training only (S), endurance training only (E), concurrent strength and endurance training (SE), or a control group (C). Groups S and E trained 3 days a week and the SE group trained 6 days a week for 12 weeks. Tests were made before and after 6 and 12 weeks of training. There was a similar increase in maximal oxygen consumption (VO2max) in both groups E and SE (P < 0.05). Leg press and knee extension one repetition maximum (1 RM) was increased in groups S and SE (P < 0.05) but the gains in knee extension 1 RM were greater for group S compared to all other groups (P < 0.05). Types I and II muscle fibre area increased after 6 and 12 weeks of strength training and after 12 weeks of combined training in type II fibres only (P < 0.05). Groups SE and E had an increase in succinate dehydrogenase activity and group E had a decrease in adenosine triphosphatase after 12 weeks of training (P < 0.05). A significant increase in capillary per fibre ratio was noted after 12 weeks of training in group SE. No changes were observed in testosterone, human growth hormone or sex hormone binding globulin concentrations for any group but there was a greater urinary cortisol concentration in the women of group SE and decrease in the men of group E after 12 weeks of training (P < 0.05). These findings would support the contention that combined strength and endurance training can suppress some of the adaptations to strength training and augment some aspects of capillarization in skeletal muscle.
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PMID:Effect of concurrent strength and endurance training on skeletal muscle properties and hormone concentrations in humans. 1075 Nov 4

Alanine is a nutritionally nonessential amino acid synthesized by transamination of pyruvate originated from glucose. Alanine is the principal gluconeogenic amino acid because it can originate pyruvate and glucose through the inverse pathway. Considering that it has been suggested that alanine could be used as a dietary supplement in combination with growth hormone in the treatment of undernourished children affected by some inherited metabolic diseases to induce anabolism, the principal objective of the present work was to measure the activities of the mitochondrial respiratory chain complexes and succinate dehydrogenase in brain cortex of Wistar rats subjected to chronic alanine administration from the 6th to the 21st day of life. We also investigated the in vitro effect of alanine on the activities of mitochondrial respiratory chain complexes and succinate dehydrogenase in the same brain structure of 22-day-old rats. The results showed a reduction of Complex I + III and succinate dehydrogenase activities in brain cortex of rats subjected to alanine administration. We also verified that alanine inhibited the in vitro activity of Complexes I + III by competition with NADH. These results indicate that more investigation would be necessary before considering alanine supplementation as a valid adjuvant therapy to sick children with these disorders.
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PMID:Inhibition of the mitochondrial respiratory chain by alanine in rat cerebral cortex. 1232 82

Mutations in the subunits B, C, D, and recently in A of the succinate dehydrogenase have been associated with the development of paragangliomas. We report the case of a 37-year-old man presented with multiple paragangliomas and a growth hormone-producing pituitary adenoma, with a novel succinate dehydrogenase subunit D mutation as the genetic analysis revealed. We present the similarities and the differences of the findings in patient imaging with either methods of SPECT (I-MIBG and In-pentetreotide) or PET/CT with F-FDG. This case revealed that F-FDG PET/CT detected more lesions and was superior compared with the other methods.
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PMID:SPECT and 18F-FDG PET/CT imaging of multiple paragangliomas and a growth hormone-producing pituitary adenoma as phenotypes from a novel succinate dehydrogenase subunit D mutation. 2415 17