Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.2 (alanine aminotransferase)
 26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The serum enzymes of pigs naturally infected with the metacestodes of Taenia solium and of uninfected pigs were assayed. Aspartate aminotransferase, alanine aminotransferase, ornithine carbamyl transferase, sorbitol dehydrogenase, lactate dehydrogenase, isocitrate dehydrogenase, alkaline phosphatase and ceruloplasmin activities were significantly increased in the serum of the infected pigs.
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PMID:Changes in serum enzyme activities in pigs naturally infected with the metacestodes of Taenia solium. 400 13

Fat-cells were prepared from rat and guinea-pig epididymal adipose tissue and compared on the basis of the intracellular distributions and activities of enzymes and with respect to their utilization of various U-(14)C-labelled substrates for lipogenesis. 1. Compared with the rat, guinea-pig extramitochondrial enzyme activities differed in that aconitate hydratase, alanine aminotransferase, ATP-citrate lyase, lactate dehydrogenase, NAD-malate dehydrogenase, NADP-malate dehydrogenase and phosphoenolpyruvate carboxykinase activities were appreciably lower, whereas aspartate aminotransferase, glucose 6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase and 6-phosphogluconate dehydrogenase activities were appreciably higher. Mitochondrial activities of citrate synthase, NADP-isocitrate dehydrogenase and pyruvate carboxylase were appreciably lower, whereas mitochondrial activities of aspartate aminotransferase, glutamate dehydrogenase, NAD-malate dehydrogenase and phosphoenolpyruvate carboxykinase were higher in the guinea pig compared with the rat. 2. In general guinea-pig fat-cells incorporated acetate and lactate into fatty acids more readily than rat fat-cells, whereas rat fat-cells incorporated glucose and pyruvate more readily than guinea-pig fat-cells. 3. Acetate stimulated the incorporation of glucose into fatty acids in rat fat-cells, but had no appreciable effect upon this process in guinea-pig fat-cells. Acetate greatly decreased the incorporation of lactate into fatty acids in cells from both species. 4. Lactate/pyruvate ratios produced by incubation of guinea-pig cells with glucose+insulin were very low compared with those found with rat cells under the same conditions. 5. With glucose (+insulin) or with glucose+acetate (+insulin) as substrates guinea-pig cells produced enough NADPH by the hexose monophosphate pathway to satisfy the NADPH requirements of lipogenesis. In rat fat-cells under the same conditions, hexose monophosphate-pathway NADPH provision was not sufficient to meet the requirements of lipogenesis. 6. These results are discussed, particularly in relationship to the disposition of cytosolic reducing equivalents in the cells.
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PMID:Lipogenesis in rat and guinea-pig isolated epididymal fat-cells. 415 67

1. A method is described for extracting separately mitochondrial and extramitochondrial enzymes from fat-cells prepared by collagenase digestion from rat epididymal fat-pads. The following distribution of enzymes has been observed (with the total activities of the enzymes as units/mg of fat-cell DNA at 25 degrees C given in parenthesis). Exclusively mitochondrial enzymes: glutamate dehydrogenase (1.8), NAD-isocitrate dehydrogenase (0.5), citrate synthase (5.2), pyruvate carboxylase (3.0); exclusively extramitochondrial enzymes: glucose 6-phosphate dehydrogenase (5.8), 6-phosphogluconate dehydrogenase (5.2), NADP-malate dehydrogenase (11.0), ATP-citrate lyase (5.1); enzymes present in both mitochondrial and extramitochondrial compartments: NADP-isocitrate dehydrogenase (3.7), NAD-malate dehydrogenase (330), aconitate hydratase (1.1), carnitine acetyltransferase (0.4), acetyl-CoA synthetase (1.0), aspartate aminotransferase (1.7), alanine aminotransferase (6.1). The mean DNA content of eight preparations of fat-cells was 109mug/g dry weight of cells. 2. Mitochondria showing respiratory control ratios of 3-6 with pyruvate, about 3 with succinate and P/O ratios of approaching 3 and 2 respectively have been isolated from fat-cells. From studies of rates of oxygen uptake and of swelling in iso-osmotic solutions of ammonium salts, it is concluded that fat-cell mitochondria are permeable to the monocarboxylic acids, pyruvate and acetate; that in the presence of phosphate they are permeable to malate and succinate and to a lesser extent oxaloacetate but not fumarate; and that in the presence of both malate and phosphate they are permeable to citrate, isocitrate and 2-oxoglutarate. In addition, isolated fat-cell mitochondria have been found to oxidize acetyl l-carnitine and, slowly, l-glycerol 3-phosphate. 3. It is concluded that the major means of transport of acetyl units into the cytoplasm for fatty acid synthesis is as citrate. Extensive transport as glutamate, 2-oxoglutarate and isocitrate, as acetate and as acetyl l-carnitine appears to be ruled out by the low activities of mitochondrial aconitate hydratase, mitochondrial acetyl-CoA hydrolyase and carnitine acetyltransferase respectively. Pathways whereby oxaloacetate generated in the cytoplasm during fatty acid synthesis by ATP-citrate lyase may be returned to mitochondria for further citrate synthesis are discussed. 4. It is also concluded that fat-cells contain pathways that will allow the excess of reducing power formed in the cytoplasm when adipose tissue is incubated in glucose and insulin to be transferred to mitochondria as l-glycerol 3-phosphate or malate. When adipose tissue is incubated in pyruvate alone, reducing power for fatty acid, l-glycerol 3-phosphate and lactate formation may be transferred to the cytoplasm as citrate and malate.
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PMID:The intracellular localization of enzymes in white-adipose-tissue fat-cells and permeability properties of fat-cell mitochondria. Transfer of acetyl units and reducing power between mitochondria and cytoplasm. 439 82

1. Transient and steady-state changes caused by acetate utilization were studied in perfused rat heart. The transient period occupied 6min and steady-state changes were followed in a further 6min of perfusion. 2. In control perfusions glucose oxidation accounted for 75% of oxygen utilization; the remaining 25% was assumed to represent oxidation of glyceride fatty acids. With acetate in the steady state, acetate oxidation accounted for 80% of oxygen utilization, which increased by 20%; glucose oxidation was almost totally suppressed. The rate of tricarboxylate-cycle turnover increased by 67% with acetate perfusion. The net yield of ATP in the steady state was not altered by acetate. 3. Acetate oxidation increased muscle concentrations of acetyl-CoA, citrate, isocitrate, 2-oxoglutarate, glutamate, alanine, AMP and glucose 6-phosphate, and lowered those of CoA and aspartate; the concentrations of pyruvate, ATP and ADP showed no detectable change. The times for maximum changes were 1min, acetyl-CoA, CoA, alanine and AMP; 6min, citrate, isocitrate, glutamate and aspartate; 2-4min, 2-oxoglutarate. Malate concentration fell in the first minute and rose to a value somewhat greater than in the control by 6min. There was a transient and rapid rise in glucose 6-phosphate concentration in the first minute superimposed on the slower rise over 6min. 4. Acetate perfusion decreased the output of lactate, the muscle concentration of lactate and the [lactate]/[pyruvate] ratio in perfusion medium and muscle in the first minute; these returned to control values by 6min. 5. During the first minute acetate decreased oxygen consumption and lowered the net yield of ATP by 30% without any significant change in muscle ATP or ADP concentrations. 6. The specific radioactivities of cycle metabolites were measured during and after a 1min pulse of [1-(14)C]acetate delivered in the first and twelfth minutes of acetate perfusion. A model based on the known flow rates and concentrations of cycle metabolites was analysed by computer simulation. The model, which assumed single pools of cycle metabolites, fitted the data well with the inclusion of an isotope-exchange reaction between isocitrate and 2-oxoglutarate+bicarbonate. The exchange was verified by perfusions with [(14)C]bicarbonate. There was no evidence for isotope exchange between citrate and acetyl-CoA or between 2-oxoglutarate and malate. There was rapid isotope equilibration between 2-oxoglutarate and glutamate, but relatively poor isotope equilibration between malate and aspartate. 7. It is concluded that the citrate synthase reaction is displaced from equilibrium in rat heart, that isocitrate dehydrogenase and aconitate hydratase may approximate to equilibrium, that alanine aminotransferase is close to equilibrium, but that aspartate transamination is slow for reasons that have yet to be investigated. 8. The slow rise in citrate concentration as compared with the rapid rise in that of acetyl-CoA is attributed to the slow generation of oxaloacetate by aspartate aminotransferase. 9. It is proposed that the tricarboxylate cycle may operate as two spans: acetyl-CoA-->2-oxoglutarate, controlled by citrate synthase, and 2-oxoglutarate-->oxaloacetate, controlled by 2-oxoglutarate dehydrogenase; a scheme for cycle control during acetate oxidation is outlined. The initiating factors are considered to be changes in acetyl-CoA, CoA and AMP concentrations brought about by acetyl-CoA synthetase. 10. Evidence is presented for a transient inhibition of phosphofructokinase during the first minute of acetate perfusion that was not due to a rise in whole-tissue citrate concentration. The probable importance of metabolite compartmentation is stressed.
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PMID:Control of the tricarboxylate cycle and its interactions with glycolysis during acetate utilization in rat heart. 544 22

Metabolism of the glutamate group of amino acids--glutamic acid, gamma-amino-butyric acid, glutamine, aspartic acid and alanine--was studied in the brain of rat as a function of age. The levels of glutamic acid, glutamine and aspartic acid decreased while those of gamma-aminobutyric acid, and alanine increased with age. The results on the activity of the twelve enzymes involved in the metabolism showed that five of them (glutamate dehydrogenase, glutamine synthase, gamma-aminobutyric acid transaminase, succinic semialdehyde dehydrogenase and NAD+-isocitrate dehydrogenase) decreased, while four of them (glutaminase, glutamotransferase, glutamic acid decarboxylase, and alpha-ketoglutarate dehydrogenase) increased. The other three enzymes (aspartate aminotransferase, alanine aminotransferase and NADP+-isocitrate dehydrogenase) did not show any significant change in activity. An age-related increase was seen in alpha-ketoglutarate and ammonia, the intermediates involved in the metabolism of these amino acids. The changes in the level of these amino acids are discussed in relation to the altered energy metabolism during aging.
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PMID:Metabolism of the glutamate group of amino acids in rat brain as a function of age. 614 62

Our previous studies indicated that the toxicity of chloro- or bromo-methanes is potentiated by chlordecone (CD). The present work was conducted to study the effect of prior dietary exposure to CD on toxicity of bromoform. Male S-D rats (175-200 g) were fed 0 or 10 ppm CD in the powdered ration for 15 days. Bromoform (25 to 300 microliters/kg) was given i.p. on day 15. 24 h later, hepatotoxicity was assessed by functional, biochemical and histopathological parameters. Excretion of phenolphthalein glucuronide in bile and the rate of bile flow were unaltered by either bromoform or CD-bromoform combination. Serum enzymes (GPT, GOT and isocitric dehydrogenase (ICD) were also not significantly elevated by any treatment. The results suggest that, unlike chloroform, CHBr3 does not act as a potent hepatotoxin and that its effects are not potentiated by CD to any significant extent.
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PMID:Absence of potentiation of bromoform hepatotoxicity and lethality by chlordecone. 618 8

The present study, conducted over a time course of 36 hr after CCl4 administration, describes sequential morphometric and biochemical changes which occur in livers of rats exposed to a combination of low levels of chlordecone (10 ppm for 15 days) and a single ip injection of CCl4 (0.1 ml/kg). Those changes were compared to hepatic alterations which occur in rats that received the same dose of chlordecone or CCl4 alone. Biochemical studies showed only trivial increases in levels of glutamic-pyruvic transaminase (GPT), glutamic-oxalacetic transaminase (GOT), and moderate but temporary increases in isocitrate dehydrogenase (ICD) after CCl4 alone. The combination of chlordecone and CCl4 resulted in significantly greater elevations of all three serum enzymes at all time intervals examined. Morphometric data showed no difference between normal diet controls and animals exposed to chlordecone alone as far as numerical density of hepatocytes or volume densities of hepatocytes with glycogen, lipid, dilated rough endoplasmic reticulum (RER), pyknosis, or mitoses. Morphometric analysis of livers from animals that received CCl4 alone showed decreases in numerical density, temporary decrease in percentage of hepatocytes containing glycogen, an increase in hepatocytes containing lipid, temporary increase in hepatocytes with dilated RER, and temporary increases in pyknotic nuclei. Soon after the initial hepatic injury was histologically evident between 4 and 6 hr, the number of mitoses increased dramatically and this progressed until complete recovery from CCl4 damage. From all indices of damage, complete recovery was evident by 36 hr after CCl4 administration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Chlordecone-induced potentiation of carbon tetrachloride hepatotoxicity: a morphometric and biochemical study. 619 13

The activity and stability of several enzymes from the facultative thermophile Bacillus flavothermus, grown within the mesophilic and thermophilic region at 34 degrees C, 43 degrees C, 52 degrees C and 70 degrees C, have been examined. While the temperature optima and maxima of all enzymes tested were found to remain unchanged at all growth temperatures, it was demonstrated that the heat stability of the proteins increased with ten perature, however, not uniformly for all enzymes. One exception was acetate kinase and the intrinsic stability of pyruvate kinase was found to increase only slightly. With all other proteins tested (alanine dehydrogenase, isocitric dehydrogenase and glucose-6-phosphate dehydrogenase, glutamate-oxalacetate and glutamate-pyruvate transaminase and myokinase) the intrinsic stability was found to increase to about 55 degrees C, but stayed unaltered at higher growth temperatures. Except for acetate kinase and myokinase, the enzymes could be stabilized by their respective substrates and the heat stability of the ES-complexes was found also to depend on the growth temperature of the cells. These data lead to the conclusion that the enzymes undergo a transition from heat-labile to thermostable within the growth temperature range between 44 degrees C and 51 degrees C while the thermal characteristics are not changed below and beyond this crucial region.
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PMID:Thermal properties of enzymes from Bacillus flavothermus, grown between 34 and 70 degrees C. 631 Oct 96

The stability of various marmoset (Callithrix jacchus) plasma constituents was investigated after storage at room temperature, 4 degrees C, and -20 degrees C. The method of sequential analysis ensured that the between-run bias of the methods of analysis used was drastically reduced, and the definitions of stability were linked to the imprecision of these methods. Optimal conditions for storage for as long as 48 h depended on the analyte being measured. Room temperature was optimal for cholinesterase and acetylcholinesterase; 4 degrees C for protein, albumin, alanine aminotransferase, isocitrate dehydrogenase, sorbitol dehydrogenase, lactate dehydrogenase, and glutamate dehydrogenase; and -20 degrees C for glutathione reductase and alkaline phosphatase. For aspartate amino-transferase and gamma-glutamyltransferase, either 4 degrees C or -20 degrees C would be suitable. Reasons are advanced for some conflicting reports in the published work, and we emphasize the need to investigate each analyte and species separately.
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PMID:Stabilities of some constituents of marmoset (Callithrix jacchus) plasma under various conditions of storage. 641 8

Groups of 8 male crossbreed domestic goats were given 3 dosage levels of aflatoxin B1 [(AFB1) mg/kg of body weight/day] orally: 0.1 for 34 days; 0.2 for 18 days; or 0.4 for 10 days. Clinical condition, feed consumption, and selected blood values were determined. Clinical signs of toxicosis included decreased feed consumption, slight-to-moderate loss of body weight, mucopurulent nasal discharge, dyspnea, coughing, lethargy, icterus, diarrhea (4 goats), and subnormal body temperature 24 to 48 hours before death. Clinicopathologic changes included increases in total RBC count, PCV, hemoglobin concentration, serum bilirubin concentration, and serum activities of aspartate aminotransferase, isocitric dehydrogenase, and ornithine carbamyl transferase. Goats given the 2 smaller dosage levels of AFB1 had slight increases of serum total protein (TP) concentration compared with control goats, but goats given the larger dosage levels of AFB1 initially had a slight decrease in TP. Aflatoxin had little effect on total WBC count. Serum alanine aminotransferase (ALT) activities in goats given the 2 larger dosage levels of AFB1 were similar to those of control goats, but goats given the smallest dosage level of AFB1 had increased serum ALT activities. Aflatoxin did not produce consistent dose-related changes in serum alkaline phosphatase activities. Seemingly, goats are susceptible to aflatoxin. Onset of clinical signs was dose-related. Onset and magnitude of increases in PCV, hemoglobin concentration, serum bilirubin concentration, and activities of serum aspartate aminotransferase, ornithine carbamyl transferase, and isocitric dehydrogenase were dose-related. Changes in TP and activities of serum ALT and alkaline phosphatase were neither dose-related nor were they potentially useful indicators of toxicosis.
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PMID:Caprine aflatoxicosis: experimental disease and clinical pathologic changes. 643 Jan 34


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