Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.3.1 (citrate synthase)
 4,488 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activity of certain enzymes of energy metabolism (cytochrome c oxidase, citrate synthase, malate dehydrogenase, and lactate dehydrogenase) and of lysosomes (beta-glucuronidase, beta-N-acetylglucosamindase, arylsuphatase, ribonuclease, deoxyribonuclease, acid phosphatase, and cathepsin D) was assayed from m. rectus femoris of mice trained 5 days per week, 1 hr per day for 4 weeks according to 4 different programmes: I. running speed 20 m/min, horizontal track, II. 25 m/min, horizontal track, III. 20 m/min 8 degrees uphill inclination, and IV. 25 m/min 8 degrees uphill inclination. Oxidative capacity increased and anaerobic capacity decreased without distinction between the different traning programmes. Of acid hydrolases assayed the activities of beta-glucuronidase and cathepsin D were increased independently of training intensity. Simultaneous histochemical observations on beta-glucuronidase and arylsulphatase activities in the contralateral m. rectus femoris showed more intense staining in red as compared to white muscle fibres. It is suggested that training affected the red fibres and that the applied level of loading was probably too low to cause major involvement of white fibres.
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PMID:Oxidative and lysosomal capacity in skeletal muscle of mice after endurance training of different intensities. 21 99

1. The changes with the time of the activities of some energy-supplying enzymes and of the hydrolytic enzyme, acid phosphatase, were studied over 2 weeks of complete ischaemia, produced in the rat soleus muscle by section of the abdominal aorta and terminal devascularization, leaving nerve and tendon intact. 2. Activities of glycolytic enzymes, oxidative enzymes, hexokinase and acid phosphatase are affected in a different manner. Activities of the glycolytic enzymes, lactate dehydrogenase, triosephosphate dehydrogenase and glycerolphosphate dehydrogenase, are lowest on the 1st day and increase thereafter. The first two reach the control values again on the 4th and 14th day, respectively, while glycerolphosphate dehydrogenase reaches about 50% of the control value on the 14th day. The maximum decrease in activity of the oxidative enzymes, citrate synthase, beta-hydroxyacyl-CoA-dehydrogenase and malate dehydrogenase occurs later (4th day); thereafter their activity returns slowly to control values, but does not reach them even on the 14th day. Hexokinase activity is slightly decreased on the 1st day; then it increased and reached on the 7th day twice the control value. Thus on the 1st day the activity of the enzymes of aerobic metabolism prevail, and on the 4th day those of anaerobic carbohydrate (glucose) metabolism; the recovery of enzyme activity of aerobic oxidation occurs later. 3. Acid phosphatase activity increased from the 2nd day onwards, reaching up to 3 times the control value on the 4th day and still twice that value on the 14th day. This agrees well with the histochemical picture of acid phosphatase. 4. Histochemical changes of alkaline phosphatase activity reveal destruction of capillary endothelial cells during the first few days after operation and their later proliferation from the periphery, correlating with the loss and recovery of oxidative enzyme activity.
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PMID:Effects of ischaemia on enzyme-activities in the soleus muscle of the rat. 57 Nov 16

Six acidic glycosidase activities in cultured human retinal pigment epithelium (RPE) cells from donors of different ages (19 to 80 years) were studied with regard to pH optimum, Km, Vmax and specific activity. For alpha-mannosidase we found significant age-dependent decreases in specific activity and Vmax but not in Km. The other glycosidases and acid phosphatase, lactate dehydrogenase (LDH) and citrate synthase showed no change in these parameters with donor age. The alpha mannosidase activity of older donor cells could be activated almost 2-fold by the addition of zinc. This is the first report of age-dependent change in a human RPE lysosomal enzyme. Since alpha-mannosidase is probably required for the degradation of rhodopsin in the phagolysosomal system of the RPE, decrease in this enzyme activity may lead to accumulation of undigested rod outer segments (ROS) and drusen, both of which are associated with age-related macular degeneration (AMD).
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PMID:A donor-age-dependent change in the activity of alpha-mannosidase in human cultured RPE cells. 280 91

Nonsynaptic mitochondria isolated from rat brain hippocampus were compared with those obtained by means of the same preparative procedure from cerebral cortex and striatum. Protein recovery, marker enzyme activities (lactate dehydrogenase, citrate synthase, and acid phosphatase), state 4 respiration, and response to hypoosmotic shock showed no difference among the three cerebral regions, suggesting homogeneous behavior during the subfractionation procedure. Cholinergic markers--choline acetyltransferase, acetylcholinesterase activities, and high-affinity choline uptake--evaluated on synaptosomes showed the classic regional pattern with an enrichment in the striatum (striatum much greater than hippocampus). The coupling state of the mitochondrial fractions was maintained (respiratory control ratios ranging from 3.62 to 5.08 with glutamate + malate as oxidizable substrates), showing a metabolic competence sufficient to perform metabolic studies. Regional differences were found in state 3, uncoupled state of respiration, and cytochrome oxidase activity. Hippocampus showed the lower values (hippocampus less than striatum less than cortex). A possible role of this lower capacity of mitochondrial energy metabolism in determining the sensitivity of hippocampal neurons to ischemia or epileptic seizures is suggested.
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PMID:Oxidative metabolism of nonsynaptic mitochondria isolated from rat brain hippocampus: a comparative regional study. 283 1

Muscle hypertrophy was induced in the soleus muscle of young rats by tenotomy of the gastrocnemius and plantaris muscles. Three and 7 days afterwards the sciatic nerve was sectioned. The loss of weight of muscles subjected to this combined procedure three days after denervation was 30-40%. Lysosomal enzyme activities (acid phosphatase, alpha-glucosidase, beta-galactosidase and N-acetyl-beta-D-glucosaminidase) and energy enzyme activities (lactate dehydrogenase, LDH, triose-3-phosphate dehydrogenase, TPDH , D-hexokinase, HK and citrate synthase, CS) were determined 3 days after denervation, 3, 7 and 10 days after hypertrophy had been induced and 3 days after denervation of hypertrophying muscles on day 3 and 7. Normal non-operated rats of corresponding body weight served as controls and their enzyme activities were estimated on the same day. In the course of muscle hypertrophy, the 4 lysosomal enzyme activities increased progressively. Although 3 days' denervation of control muscles did not alter lysosomal enzyme activities, denervation of hypertrophying muscles greatly enhanced the activity of these enzymes. Enzymes of energy metabolism were affected to a lesser degree. The results suggest that denervation of hypertrophying muscles causes more extreme changes in muscle weight and lysosomal enzyme activities than denervation alone. The possible implications of this finding are discussed in relation to the rapid atrophy.
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PMID:Lysosomal and energy enzyme activities in hypertrophied rat soleus muscle after denervation. 671 25

The purpose of this study was to investigate whether vitamin D3 deficiency and 1,25-dihydroxyvitamin D3 treatment affect some aspects of heart metabolism in the rat. To this end, five experimental groups were studied: (1) the control group of the vitamin D3 supplemented rats (Group A); (2) rachitic rats (Group B); (3) rachitic rats treated with 1,25-dihydroxyvitamin D3 (Group C); (4) rats fed a vitamin D-deficient diet (Group D); (5) rats fed a vitamin D-deficient diet and treated with 1,25-dihydroxyvitamin D3 (Group E). The five groups were compared by checking in the heart some metabolic parameters, i.e. citrate content, and enzyme activities in cytosol and mitochondria. Citrate content was higher in the heart of treated animals when compared with the control. As regards the enzymatic activities in heart mitochondria, NAD(+)-dependent isocitrate dehydrogenase remarkably decreased in Group B rats and 1,25-dihydroxyvitamin D3 restored quite normal values. NADP(+)-dependent isocitrate dehydrogenase decreased in Group B and Group D animals, and 1,25-dihydroxyvitamin D3 treatment was effective in restoring control values. Cytochrome c oxidase activity did not change, while citrate synthase showed an increase in all the treated rats. As regards the cytosolic enzymes, fructose-6-phosphate kinase increased in the two groups of vitamin D-deplete rats in comparison with the control. Glyceraldehyde-3-phosphate dehydrogenase and 3-phosphoglycerate kinase showed a similar trend: an increase in all the treated animals. In heart homogenate, acylphosphatase and acid phosphatase activities were also determined. Acylphosphatase increased in the treated rats, while acid phosphatase decreased in the rats injected with 1,25-dihydroxyvitamin D3. These results support the hypothesis of a participation of 1,25-dihydroxyvitamin D3 in some aspects of heart metabolism.
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PMID:Effect of vitamin D deficiency and 1,25-dihydroxyvitamin D3 on rat heart metabolism. 789 66

We previously demonstrated that feeding rats the Steenbock and Black rickets-inducing diet produces remarkable changes in the metabolic pattern of intestinal mucosa, kidney, liver, cerebral cortex and heart. We have now determined the levels of calcium, phosphorus and citrate in cerebral cortex and the activity of some enzymes in synaptosomes and cerebral cortex mitochondria of three rat groups: control (Group A), fed a vitamin D-deficient diet (Group B), fed a vitamin D-deficient diet and treated with 1,25-dihydroxyvitamin D3 (Group C). While calcium content increased in Groups B and C, phosphorus concentration increased only in Group C and citrate in Group B in comparison with control. The increase in acetylcholinesterase and citrate synthase registered in Group B was restored to control values by 1,25-dihydroxyvitamin D3 treatment, while, neither the decrease in cytochrome c oxidase, nor the increase in glucose-6-phosphate dehydrogenase, acid phosphatase and NADP+(-)isocitrate dehydrogenase observed in Group B were corrected by 1,25-dihydroxyvitamin D3 supply. Acyl phosphatase showed a remarkable increase in consequence of 1,25-dihydroxyvitamin D3 administration.
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PMID:Vitamin D--related modification of enzyme activities in synaptosomes and mitochondria isolated from rat cerebral cortex. 862 85

Cadmium distribution was studied in different subcellular fractions of gill and hepatopancreas tissues of eastern oysters Crassostrea virginica. Oysters were exposed for up to 21 days to low sublethal Cd concentrations (25 microg L(-1)). Gill and hepatopancreas tissues were sampled and divided into organelle fractions and cytosol by differential centrifugation. Organelle content of different fractions was verified by activities of marker enzymes, citrate synthase and acid phosphatase for mitochondria and lysosomes, respectively. In both tissue types, there was a significant accumulation of cadmium in cytosol reaching 230-350 ng mg(-1) protein. Among organelles, mitochondria were the main target for Cd bioaccumulation in gills (250-300 ng mg(-1) protein), whereas in hepatopancreas tissues, the highest cadmium accumulation occurred in lysosomes (90-94 ng mg(-1) protein). Although 75-83% of total cadmium burden was associated with the cytosol reflecting high volume fraction of this compartment, Cd concentrations in organelle fractions reached levels that could cause dysfunction of mitochondria and lysosomes. Organ- and organelle-specific patterns of cadmium bioaccumulation support our previous in vivo studies, which showed adverse effects of cadmium exposures on mitochondrial oxidation in gills and on the lysosomal system of hepatopancreas. This may have important implications for the development of biomarkers of effect for heavy metals and for understanding the mechanisms of toxic effects of metals.
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PMID:Tissue-specific accumulation of cadmium in subcellular compartments of eastern oysters Crassostrea virginica Gmelin (Bivalvia: Ostreidae). 1599 95