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 activity of certain key enzymes involved in glutamic acid metabolism was studied in purified brain mitochondria and in mitochondrial subfractions separated in a discontinuous 1.2--1.6 mol/l sucrose gradient. Alanine aminotransferase and glutamate dehydrogenase were found to be matrix enzymes and aspartate aminotransferase to be associated with the inner mitochondrial membranes. After the purified mitochondria had been separated into 5 subfractions, aspartate aminotransferase and NAD+-dependent isocitrate dehydrogenase were found to be bound to the lighter mitochondrial subfractions settling at the 1.4--1.5 mol/l sucrose boundary while alanine aminotransferase, 4-aminobutyrate transaminase and glutamate dehydrogenase were associated with the heavier subfractions settling below 2.4 mol/l sucrose. The highest specific activity of the given enzymes was found in the subfraction settling at the 1.4--1.5 mol/l sucrose boundary, the only exception being alanine aminotransferase activity, whose maximum was found in the subfractions settling in 1.5 and 1.6 mol/l sucrose. It was concluded that alanine aminotransferase, in conjunction with glutamate dehydrogenase, is linked to NH3 binding and to the oxidation of reduced adenine nucleotides; in addition, alanine aminotransferase is presumed to have the function of transporting glutamate from the mitochondria to the extramitochondrial space.
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PMID:Alanine aminotransferase and some other enzymes in different populations of free brain cortex mitochondria. 645 52

Crocodilians such as caimans and alligators are uricotelic and ammoniotelic animals. They are carnivorous but they excrete ammonium ions in an alkaline urine. The metabolic organization of the kidney of the Mississippi alligator was studied by measuring the renal metabolite profile, the activities of enzymes, and the behavior of kidney tubules in vitro. The liver and tail muscle were also studied. Both awake and anesthetized animals were in a state of low plasma bicarbonate and low blood pH with high plasma lactate concentration. This did not prevent the excretion of an alkaline urine (pH 7.76). alpha-Ketoglutarate was low in all three tissues and lactate was high. Glutamate concentration and glutamate dehydrogenase activity were highest in the kidney with a low equilibrium constant for alanine aminotransferase (KGPT). Glutaminase I was found only in the kidney. It could not be detected in liver or muscle. Glutamine synthetase was found only in the liver. Phosphoenolpyruvate carboxykinase (PEPCK) was present in both liver and kidney. Alanine aminotransferase and malic enzyme showed high activity in the kidney but were inconspicuous in liver and muscle. Malate dehydrogenase and lactate dehydrogenase were present in all three tissues. Renal tubules incubated with glutamine and alanine were ammoniagenic and gluconeogenic. Lactate was gluconeogenic. Enzyme activities were measured at both 30 and 37 degrees C. The studies on renal tubules were also performed at these two temperatures. Temperature had little effect on the data including acid-base values in the blood. Our findings demonstrate that the kidney of the alligator is perfectly equipped for various metabolic functions and especially for ammoniagenesis and gluconeogenesis.
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PMID:Metabolic machinery of the alligator kidney. 649 95

The present study was designed to test if both the intensity and duration of the 45-min Square-Wave Endurance Exercise Test (SWEET) would produce changes in serum enzyme activities. Nine men, four sedentary (S) and five athletes (A), performed VO2 max and SWEET, at their Maximal Intensity of Endurance (MIE45) as defined by maximal heart rate and the impossibility of maintaining MIE 45 + 5% for 45 min. Arterial blood was sampled at rest (R), exercise (Ex) (45th min) and during recovery (15th min) for measurements of levels of Haemoglobin (Hb), Haematocrit (Hct), pH and seven serum enzymes: Creatine kinase (CPK), Hexose-phosphate isomerase (PHI), Aldolase (ALD), Lactate dehydrogenase (LDH), Malate dehydrogenase (MDH), Aspartate amino-transferase (ASAT or GOT), and Alanine aminotransferase (ALAT or GPT). Five enzymes increased significantly during exercise (MIE45), the delta % (Ex - R/R) increases were as follows: PHI (72%), MDH (28%), LDH (21%), CPK (17%), and GOT (13.5%), whilst only a 10% increase was observed for Hct and Hb and there was no significant change in the arterial pH. There was no correlation between the delta % of Hb, Hct, pH, and the results for the enzymes. Thus, it does not seem that haemoconcentration and arterial blood acidosis which occur during exercise are only at the origin of the observed increases in enzymes. A difference between "sedentary" and "athletes" subjects was found at rest and exercise (delta % = A - S/S) for CPK (R = 222%; Ex = 235%), GOT (R = 90%; Ex = 75%) and ALD (R = 99%; Ex = 54%). These results suggest that the MIE45, by measured increases in enzymatic activity, seems to require great muscular effort.
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PMID:Serum enzyme variations in men during an exhaustive "square-wave" endurance exercise test. 653 38

Using lyophilized cryostat sections of liver the activities of alanine aminotransferase, lactate dehydrogenase, and pyruvate kinase were measured using a Lowry technique in the first layer of hepatocytes adjacent to terminal hepatic venules and in the residual parenchymal of the perivenous zone of the acinus in normally fed adult male Wistar rats. Alanine aminotransferase was homogeneously distributed in the two areas measured (ratio hepatocytes adjacent to terminal hepatic venules/residual parenchyma of the perivenous zone: 1.05). Enzyme activities of the lactate dehydrogenase were significantly lower in the hepatocytes adjacent to terminal hepatic venules (ratio: 0.65) and those of the pyruvate kinase significantly higher (ratio: 1.12) than in the residual parenchyma of the perivenous zone indicating liver cell heterogeneity in this zone of the liver acinus.
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PMID:Microbiochemical approach to liver cell heterogeneity around terminal hepatic venules. 661 16

Everyday administration of citrate (250 mg/kg of body mass) into healthy rats within 4 days inhibited activities of pyruvate kinase, pyruvate dehydrogenase, alanine transaminase and of reverse lactate dehydrogenase in liver tissue but not in sceletal muscles. Within the longer period of citrate administration (8 or 12 days) activities of pyruvate dehydrogenase and alanine transaminase continued to decrease in liver tissue, at the same time, content of pyruvate proceeded to increase in sceletal muscles. More distinct inhibitory effect of citrate on the pyruvate dehydrogenase activity was observed not only in liver tissue but and in sceletal muscles of tumor-bearing animals. Alanine transaminase, which was inactivated in liver tissue of healthy animals after citrate treatment, was markedly activated in tumor-bearing rats in the same conditions. The data obtained suggest that some regulatory functions of citrate were qualitatively transformed in tumor-bearing animals, mainly, in relation to turnover of glucogenic amino acids.
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PMID:[Features of pyruvate and lactate metabolism in tumor-bearing rats following citrate administration]. 746 8

Alanine aminotransferase (Alt, L-alanine:2-oxoglutalate aminotransferase) is a pyridoxal enzyme which catalyses the reversible interconversion of L-alanine and 2-oxoglutalate to pyruvate and L-glutamate. The enzyme is widely distributed in various tissues from animals and even in some kind of plants. Isoenzymes of human ALT localize in the cytosol (c-ALT) and mitochondria (m-ALT) of tissues such as liver, kidney, skeletal and cardiac muscles. Amino acid sequence of c-ALT from rat and human liver has been wholly determined by Ishiguro et al. It is suggested that c-ALT is associated to the utilization of pyruvate in glycolysis and m-ALT is involved in the conversion of alanine to pyruvate for gluconeogenesis.
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PMID:[Alanine aminotransferase (ALT)]. 760 70

Alanine aminotransferase (AlaAT; EC 2.6.1.2) was purified to homogeneity from Candida maltosa that was grown on L-alanine as the sole source of carbon and nitrogen. The enzyme has a molecular mass of 99kDa and consists of two subunits of equal molecular mass (52 kDa). Each subunit binds one mole of PLP. The enzyme has an isoelectric point of 5.3 and an optimum pH of 6.0-7.5. The spectroscopic profile and an inhibition experiment showed that both PLP and free-SH groups are directly involved in the enzymatic catalysis. In the N-terminal region of the enzyme, the consensus sequence (five amino acids) that commonly appears in mammalian and higher plant enzymes is present. Compared with mammalian enzyme, the Candida AlaAT is heat-sensitive and a little looser in substrate specificity, and its affinity towards L-alanine is high.
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PMID:Purification and some properties of alanine aminotransferase from Candida maltosa. 776 40

Thirty children with sickle cell anaemia had their serum alanine aminotransferase, alkaline phosphatase, total protein, albumin and bilirubin, assayed during vaso-occlusive crisis and at recovery. Alanine aminotransferase, alkaline phosphatase and bilirubin levels were significantly higher during crisis than at recovery, (p < 0.005) especially in the young patient. However, the total protein and albumin levels were not significantly different in crisis and at recovery. A transient hepatic functional derangement during vaso-occlusive crisis is a probable explanation for the reported changes.
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PMID:Hepatic function tests in children with sickle cell anaemia during vaso occlusive crisis. 788 14

We have examined the effects of administration of the blood substitute, liposome-encapsulated haemoglobin (LEH), in the normovolaemic rat. Test groups included LEH, lyophilized EH, the liposome vehicle, unencapsulated haemoglobin and normal saline, which were injected into the tail vein (n = 6; n = 3 for sham and saline groups). Administration of LEH (2.5 g phospholipid, 1.25 g haemoglobin/kg rat) was followed by blood sampling at 2 h, 24 h, 1 wk and 2 wk. Blood samples were analysed for alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransferase, total and indirect bilirubin, serum creatinine, albumin, total protein, lipase, cholesterol, blood urea nitrogen, haematocrit, haemoglobin and differential white blood cell counts. Observed effects following injection were mild and transient, with baseline values recovered at 1 wk. Alanine aminotransferase increased moderately in the LEH group at 24 h to 601 +/- 143 IU/dl (P < 0.0001), with a return to baseline at 1 wk. Aspartate aminotransferase showed a smaller increase from 46 +/- 5 to 162 +/- 40 at 24 h and also returned to baseline at the 1 wk measurement (P < 0.001). The transient increase in serum transaminases was not observed for the lyophilized LEH group. Tissue sections showed accumulation of liposome groups in resident macrophages of the liver and spleen. Incubation of an adherent population of human peripheral blood monocytes with LEH in culture did not elicit the production of the inflammatory cytokine, tumour necrosis factor. Pre-incubation of monocytes with LEH prior to exposure to endotoxin did, however, result in a reduced expression of this inflammatory cytokine.
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PMID:Transient changes in the mononuclear phagocyte system following administration of the blood substitute liposome-encapsulated haemoglobin. 798 44

Blood alpha-fetoprotein, carcinoembyronic antigen, CA-19-9, alkaline phosphatase, gamma-glutamyltranspeptidase, alanine aminotransferase, aspartate aminotransferase, sorbitol dehydrogenase, glutamate dehydrogenase, hemoglobin and red cell sedimentation rate were measured in patients with stages III and IV gastric carcinoma and patients with benign diseases of the stomach. Alanine aminotransferase, sorbitol dehydrogenase and glutamate dehydrogenase were found diagnostically not informative in gastric carcinoma stages III and IV. A complex of measurements of alpha-fetoprotein, alkaline phosphatase, gamma-glutamyl transpeptidase and aspartate aminotransferase detected gastric carcinoma metastases to the liver in 84.6% of cases as against 61.5% detected by measurements of alpha-fetoprotein alone. A complex of measurements of carcinoembryonic antigen, CA-19-9, alkaline phosphatase, gamma-glutamyl transpeptidase, aspartate aminotransferase helped differentiate between gastric carcinoma stages III and IV. A complex of measurements of carcinoembryonic antigen, CA-19-9, alkaline phosphatase, gamma-glutamyl transpeptidase, aspartate aminotransferase, hemoglobin, and red cell sedimentation rate improved the diagnostic sensitivity in detection of gastric carcinoma stages III and IV to 70.8 and 100%, respectively.
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PMID:[Laboratory tests in the diagnosis of stomach cancer]. 800 Jul 94


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