Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.27 (lactate dehydrogenase)
 29,211 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the mixed body lymph of the thoracic duct and in the defined organ lymph of the liver and the intestine, the catalytic activity concentrations of up to sixteen enzymes and the concentrations of albumin and protein were determined, as well as the transport rate of these substances and their lymph/plasma ratio. Thoracic duct lymph specimens were obtained from an extracorporeal lymph shunt in anaesthetized and conscious dogs and from short-term fistulas in anaesthetized rabbits, rats and mice. Additionally, rabbits and rats underwent passive motion of the hind limbs in another experimental trial. Thoracic duct flow in anaesthetized dogs is only half that seen in conscious dogs, due to bypassed muscular lymph. A similar flow change is seen during passive motion of hind limbs in anaesthetized rabbits and rats. From a literature review of flow in the four main lymphatics of the body, it is concluded that the thoracic duct flow should account for 50-70% of total body lymph flow. In the anaesthetized state, flow is mainly of visceral origin. In the conscious state and during passive motion the increased flow is of muscular origin. In the latter case, the catalytic activities of enzymes like lactate dehydrogenase, malate dehydrogenase, creatine kinase, aldolase and phosphohexose isomerase, increase in lymph as does their lymph/plasma ratio. These enzymes have high catalytic activities in muscle. Their transport into the blood increases 2-3-fold, due to a doubling of lymph flow. Reported data for anaesthetized and immobile animals therefore far underestimate the significance of thoracic duct enzyme transport. Liver lymph was obtained from anaesthetized dogs and rabbits. Our finding that lymph catalytic activity for several enzymes is higher than in plasma is not compatible with the proposed delivery of plasma proteins directly into the sinusoidal space without prior mixing with the Space of Disse. Enzymes in liver lymph should derive from parenchymal and endothelial lining cells. Their site of delivery from the hepatocyte seems different from that of proteins. Liver lymph is an important transport route of enzymes into the blood. Intestinal lymph was sampled from anaesthetized dogs, rabbits and rats. It was shown that most enzymes from the intestine are primarily released into the interstitial space and from there are transported via the lymph into the blood.
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PMID:Catalytic enzyme activity concentration in thoracic duct, liver, and intestinal lymph of the dog, the rabbit, the rat and the mouse. Approach to a quantitative diagnostic enzymology, II. Communication. 370 Dec 68

In three groups of healthy young subjects (n = 33; mean ages 6.4, 13.5, 17.1 years), muscle enzyme activities (creatine kinase, hexose phosphate isomerase, aldolase, pyruvate kinase, lactate dehydrogenase, citrate synthase, fumarase) of the vastus lateralis muscle were investigated to show age-dependent variations. A significant age-dependent increase in aldolase (P less than 0.05) and pyruvate kinase (P less than 0.01) activity and a decrease in fumarase activity (P less than 0.01) were computed. In relation to the age-dependent variation, maximum LDH activities could be measured at an age of 12-14 years; significantly decreased activities of the glycolytic enzymes could only be found in the youngest group.
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PMID:Skeletal muscle enzyme activities in healthy young subjects. 375 6

Enzymes of the Embden-Meyerhof-Parnas pathway and hexose monophosphate shunt were examined in cytoplasmic extracts of three serovars of Ureaplasma urealyticum. We found no glucose-6-phosphate or 6-phosphogluconate dehydrogenase, hexokinase, phosphoglucose isomerase, aldolase, or lactic dehydrogenase activities. We failed to find cytochrome pigments in extracts and found no significant production of 14CO2 from [U-14C]glucose, nor did we find oxygen-dependent reduced nicotinamide adenine dinucleotide oxidase activity. Lactic acid was found only at trace levels in spent culture fluids. Ureaplasmas are apparently nonfermentative and are unlike all other mollicutes in that they have no detectable oxygen-dependent reduced nicotinamide adenine dinucleotide oxidase activity.
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PMID:Metabolic distinctiveness of ureaplasmas. 379 29

Primary breast cancers from 85 patients undergoing post-surgical adjuvant chemotherapy were analyzed for five glycolytic enzymes: lactate dehydrogenase (LDH); phosphohexose isomerase (PHI); glucose-6-phosphate dehydrogenase (G-6PD); pyruvate-kinase (PK); and 6-phospho-gluconate dehydrogenase (6-PGD). The purpose of this study was to determine whether biochemical parameters could offer a prognostic index to determine outcome of therapy. The patients were followed up to a maximum of 54 months; during this period 30 of them developed recurrent or metastatic disease. The enzyme activities were expressed by the three following reference parameters: units/g proteins, units/g tissue weight and units/mg DNA. Two methods of analysis were compared: firstly, univariate analysis using life tables; and secondly, multivariate analysis using the Cox's model, where enzyme levels were tested for each mode of expression in addition to node status, histological features, receptor and menopausal status. Life table analyses appear limited when subsets of patients were studied because the sample size tends to become too small to warrant firm conclusions. Using the Cox's model, a prognostic index 1 was proposed, including the number of involved nodes and the product of logarithms of G-6PD and 6-PGD expressed as units/mg DNA. Compared to the number of involved nodes, this index gives a slightly better discrimination of the patients at 2 yr after mastectomy.
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PMID:Tissue glycolytic enzymes in primary breast cancer patients receiving adjuvant chemotherapy. 395 56

Rats inoculated with Streptococcus faecalis developed endocarditis and demonstrated a 6- to 30-fold increase in aldolase, isocitric dehydrogenase, phosphohexose isomerase, and lactic dehydrogenase. The animals infected with Bacillus subtilis did not develop overt disease nor significant increases in enzyme activities, but viable organisms were recovered at 2 weeks. Rats inoculated with mixed culture of these organisms showed a 2- to 10-fold increase of enzyme activities without evidence of pathological anatomic changes. Both organisms were recovered at necropsy. The total protein and glycoproteins followed the patterns of enzyme activities. There were major changes in alpha(1), alpha(2), and beta globulins and glycoglobuulins at the early stages of infection. The protein-bound hexose changes coincided with the severity of S. faecalis infection, but were at normal levels after 72 hr of infection of B. subtilis and S. faecalis mixed infections. The results indicate that B. subtilis infection modified the pathogenicity of S. faecalis and by an unknown mechanism affected protein and glycoprotein production in serum of experimental rats.
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PMID:Biochemical changes in serum of pure and mixed Streptococcus faecalis and Bacillus subtilis infections in rats. 418 98

1. Measurements were made of the activities of nine glycolytic enzymes in epididymal adipose tissues obtained from rats that had undergone one of the following treatments: starvation; starvation followed by re-feeding with bread or high-fat diet; feeding with fat without preliminary starvation; alloxan-diabetes; alloxan-diabetes followed by insulin therapy. 2. In general, the activities of the glycolytic enzymes of adipose tissue, unlike those of liver, were not greatly affected by the above treatments. 3. The ;key' glycolytic enzymes, phosphofructokinase and pyruvate kinase, were generally no more adaptive in response to physiological factors than other glycolytic enzymes such as glucose phosphate isomerase, fructose diphosphate aldolase, triose phosphate isomerase, glycerol 3-phosphate dehydrogenase, phosphoglycerate kinase and lactate dehydrogenase. 4. Adiposetissue pyruvate kinase did not respond to feeding with fat in a manner similar to the liver enzyme. 5. Glyceraldehyde phosphate dehydrogenase had a behaviour pattern unlike the other eight glycolytic enzymes studied in that its activity was depressed by feeding with fat and was not restored to normal by re-feeding with a high-fat diet after starvation. These results are discussed in relation to the requirements of adipose tissue for glycerol phosphate in the esterification of fatty acids. 6. A statistical analysis of the results permitted the writing of linear equations describing the relationships between the activities of eight of the enzymes studied. 7. Evidence is presented for the existence of two constant-proportion groups amongst the enzymes studied, namely (i) glucose phosphate isomerase, phosphoglycerate kinase and lactate dehydrogenase, and (ii) triose phosphate isomerase, fructose diphosphate aldolase and pyruvate kinase. 8. Mechanisms for maintaining the observed relationships between the activities of the enzymes in the tissue are discussed.
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PMID:The effect of dietary and hormonal conditions on the activities of glycolytic enzymes in rat epididymal adipose tissue. 424 55

The effect of type 5 adenovirus infection on the synthesis of host-cell proteins by suspension cultures of KB cells was investigated. Although total protein synthesis continued at a constant rate for approximately 36 hr, net synthesis of five host enzymes (lactic dehydrogenase, acid phosphatase, deoxyribonuclease, fumarase, and phosphoglucose isomerase) was found to stop 16 to 20 hr after infection. The synthesis of alkaline phosphatase stopped 9 to 12 hr after infection. The inhibition of host protein synthesis occurred shortly after the synthesis of viral antigens had begun, accounting for the continued synthesis of total protein. An investigation of the relationship between synthesis of viral antigens and inhibition of host protein synthesis yielded results which suggest that the two processes are in some way coupled.
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PMID:Inhibition of host protein synthesis in type 5 adenovirus-infected cells. 424 53

Human platelets were separated by desity-centrifugation into heavy and light populations. Heavy platelets have an average volume approximately twofold greater than light platelets, and have previously been shown to be young platelets. All 11 enzymes of the Embden-Meyerhof pathway plus the five related enzymes: phosphoglucomutase, glucose-6-P dehydrogenase, 6-P-gluconic dehydrogenase, alpha-glycerol-P dehydrogenase, and glutathione reductase (TPNH) were examined in cell lysates from total, heavy, and light platelet populations. Apparent Km for individual enzymes were measured in a total platelet population. Empirical V(max) of the individual enzymes were measured in total, heavy, and light platelet populations. The three apparent rate-limiting enzymes for glycolysis were hexokinase, phosphofructokinase, and glyceraldehyde-3-P dehydrogenase. Heavy platelets contained approximately twofold greater enzyme activity (per gram wet weight) than light platelets for 7 of the 16 enzymes measured: hexokinase, phosphohexoisomerase, phosphofructokinase, glyceraldehyde-3-P dehydrogenase, phosphoglycerokinase, lactic dehydrogenase, and phosphoglucomutase. Heavy platelets also contained 1.9-fold greater reduced glutathione (GSH), 1.7-fold greater DPNH, and 1.2-fold greater TPNH than light platelets. Heavy platelets contained 1.8-fold less lipid peroxidation products (malonyl aldehyde equivalents) than light platelets and were 2.4-fold more resistant to lipid peroxidation catalyzed by 0.1 mM FeCl(3). Sterile incubation of heavy platelets, in vitro for 17 hr, resulted in a significant loss of enzyme activity for the "elevated" seven enzymes when compared with the remainder. Reducing agents such as GSH (0.1 mM), ascorbic acid (0.1 mM), and dithiothreitol (0.01 mM), when added to the incubation mixture, significantly reduced the in vitro loss of activity. In vitro incubation was also associated with a significant loss of GSH and DPNH and a 1.8-fold increase in lipid peroxidation products.
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PMID:Heterogeneity of human platelets. V. Differences in glycolytic and related enzymes with possible relation to platelet age. 426 50

Increasing concentrations of sodium octanoate were progressively inhibitory to the activities of glucokinase, hexokinase, phosphofructokinase, and pyruvate kinase. Glucose-6-phosphate and 6-phosphogluconate dehydrogenases were also markedly inhibited. Other enzymes of carbohydrate metabolism such as lactate dehydrogenase, phosphohexose isomerase, and fructose-1,6-diphosphatase were not decreased. Among the key glycolytic enzymes, the inhibition of pyruvate kinase by the fatty acid was most marked. The biological significance of the inhibition of the key glycolytic enzymes is interpreted as a feedback inhibitory mechanism in regulation of fatty acid biosynthesis. The mechanism may function for rapid adaptation by which the organism can use the fatty acid level as a metabolic directional switch in decreasing glycolysis and turning on gluconeogenesis.
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PMID:Feedback inhibition of key glycolytic enzymes in liver: action of free fatty acids. 428 79

Octanoic acid inhibits, in vitro, the bacterial enzymes glucose-6-phosphate dehydrogenase, phosphofructokinase, pyruvate kinase, fumarase, lactate dehydrogenase, and the malic enzyme of Arthrobacter crystallopoietes. The free fatty acid appears to act as an inhibitor of lipogenesis, although it does not affect the rate of gluconeogenesis. To demonstrate that this inhibition may be of physiological significance in vivo, those enzymes not involved in lipogenesis, such as fructose-1, 6-diphosphatase, phosphoglucomutase, phosphohexoisomerase, aconitase, nicotinamide adenine dinucleotide phosphate (NADP) isocitrate dehydrogenase, NADP glutamate dehydrogenase, malate dehydrogenase, and isocitrate lyase, were assayed and found not to be inhibited by the free fatty acid.
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PMID:Selective inhibition of bacterial enzymes by free fatty acids. 430 71


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