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 authors describe different properties of brain mitochondrial and cell sap alanine aminotransferase. They showed that the mitochondrial enzyme was inhibited by maleate, chlorides, acetate and phosphate with a high ionic strength (over 1.8), that its pH optimum lay between 7.5 and 8.5, that it was thermolabile at over 40 degrees C and that it was salted out from solutions with ammonium sulphate at 0.6--0.8 saturation. The activity of the cell sap enzyme was inhibited by phosphate at an ionic strength of only 0.12, less markedly by maleate and not at all by chlorides and acetate; its pH optimum was about 8, it was thermostable up to 60 degrees C and was precipitated from ammonium sulphate solution at between 0.35 and 0.6 saturation. The authors conclude from their results that two different alanine aminotransferase enzymes are present in the CNS.
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PMID:Some psysicochemical properties of mitochondrial and cell sap alanine aminotransferase from the rat CNS. 0 Jul 1

1)The time course of changes in concentration of renal metabolites in response to a non-toxic load of NH4 as NH4 Cl or NH4HCO3 were measured in fasted rats. 2) Following a NH4Cl load, decrease of renal concentration of 2-oxoglutarate occurs but this change is delayed in relation to the peak of the blood ammonia concentration and persists after disappearance of the hyperammoniemia. 3) Following a NH4HCO3 load, the oxoglutarate concentration changes are less marked and more transient. 4) No close relationship between the mitochondrial free NAD/NADH ratio calculated from the glutamate dehydrogenase and the 3-hydroxybutyrate dehydrogenase systems were seen during alteration of the ammonia concentration. 5) Contrary to the observations in the liver under similar circumstances (BROSNAN, J.T. et al.: Biochem.J. 138, 453, 1974), no increase in kidney tissue or renal venous blood alanine or aspartate concentration are seen. 6) A constant infusion of NH4HCO3 resulted only in an increase in tissue and renal venous blood glutamine concentration. 7) The infusion of NH4 together with a carbon source (malate) resulted in a similar increase in tissue glutamine concentration and more striking increase in renal venous glutamine concentration. No accumulation of aspartate nor alanine were seen. 8) In vitro studies indicate that the net flux through both the aspartate aminotransferase and the glutamate dehydrogenase reactions is dependent on the concentration of the reactants as expected for a near-equilibrium system. 9) It is concluded that the kidney response to an ammonia load differs from that of the liver despite the existence of a similar network of near-equilibrium reactions of (1) a lack of local availability of oxaloacetate, (2) a lower activity of alanine aminotransferase, (3) a greater in vivo activity of glutamine synthetase.
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PMID:Effect of an ammonia load on the kidney near-equilibrium systems in the rat in vivo. 18 80

Changes in serum amino acid levels and time course of hepatic function derangements were studied in mongrel dogs with choledochus ligature and subsequent biliarly reconstruction through cholecysto-duodenostomy. In the second week after choledochus ligature, serum ammonium level increased along with intensification of jaundice. After four weeks, GPT activity was higher than GOT and plasma albumin level markedly decreased with similar reduction in serum amino acid levels. Biliary reconstruction, when performed during three or four weeks after the ligature, restored the hepatic function as well as serum amino acid levels toward normal. When it was performed in the fifth or sixth week after the ligation, the liver function did not restore and serum levels of total amino acids, essential and non-essential amino acids increased even 4 weeks lapse after reconstruction. Among the changes observed, His., Val., Ser., Arg., Leu., Ileu, Phe, and Lys. were increased, whereas Pro. and Cys. disappeared from the serum. These results suggest that recovery from metabolic changes of amino acids due to choledochus ligature depends upon the duration of obstructive jaundice, i.e., it appears necessary to perform the biliary reconstruction within four weeks after the initiation of obstruction.
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PMID:[Experimental study on changes in serum amino acid levels following choledochus ligature and subsequent biliary reconstruction (author's transl)]. 82 88

The synthesis and release of alanine and glutamine have been studied in the intact rat epitrochlaris skeletal muscle preparation. Aspartate, cysteine, leucine, valine, methionine, isoleucine, serine, theronine, and glycine increased significantly the formation and release of alanine from muscle. Cysteine, leucine, valine, methionine, isoleucine, tyrosine, lysine, and phenylalanine increased the rate of glutamine synthesis. Only ornithine, arginine, and tryptophan were without effect on the synthesis of either alanine or glutamine. Half-maximal stimulation of alanine and glutamine formation by added amino acids was observed with concentrations ranging between 0.5 and 1.0 mM. Increases in alanine and glutamine formation were not accompanied by changes in pyruvate production or glucose uptake. The progressive decline in alanine and glutamine synthesis noted on prolonged incubation was prevented by the addition of amino acids to the incubation medium. Stimulation of alanine synthesis by added amino acids was unaffected by inhibition of glycolysis with iodoacetate. Inhibition of alanine aminotransferase with aminooxyacetate significantly decreased alanine formation. Pyruvate and ammonium chloride did not increase further the rate of either alanine or glutamine formation above that produced by added amino acids. These data indicate that most amino acids are precursors for alanine and glutamine synthesis in skeletal muscle. A general mechanism is presented for the de novo formation of alanine from amino acids in skeletal muscle, and the importance of proteolysis for the supply of amino acid precursors for alanine and glutamine synthesis is discussed.
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PMID:Alanine and glutamine synthesis and release from skeletal muscle. II. The precursor role of amino acids in alanine and glutamine synthesis. 124 59

The effect of subacute and acute doses of ammonium acetate was studied on the production of 14CO2 from 14C-labeled glutamate and aspartate by neuronal perikarya and synaptosomes isolated from rat cerebellum. Studies with inhibitors for aminotransferases (aminooxy acetic acid) and glutamate dehydrogenase (glutamic acid diethyl ester) indicated that transamination reactions play a major role in this process. There was a suppression in this process in hyperammonemic states. Activities of the enzymes, aspartate aminotransferase, alanine aminotransferase, glutamate dehydrogenase and glutaminase were decreased in both preparations in hyperammonemic states. Activity of glutamine synthetase was unaltered.
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PMID:Ammonia-induced alterations in the metabolism of glutamate and aspartate in neuronal perikarya and synaptosomes of rat cerebellum. 135 57

The medical records of 18 dogs that had hepatic disease and received phenobarbital as an anticonvulsant for 5 to 82 months were reviewed. Clinical signs included sedation and ataxia in all dogs, 5 dogs were also anorectic, 2 had coagulopathy, 3 were icteric, and 5 had ascites. Serum biochemical analysis revealed serum albumin concentration less than or equal to 2.2. g/dl in 12 dogs, serum alkaline phosphatase activity greater than or equal to 169 U/L in 18 dogs, serum alanine transaminase activity greater than or equal to 57 U/L in 15 dogs, and total bilirubin concentration greater than or equal to 1 mg/dl (in the absence of lipemia) in 7 dogs. Serum phenobarbital concentration was greater than or equal to 40 micrograms/ml in 12 of 17 dogs. Sulfobromophthalein excretion was prolonged in 8 of 10 dogs. Preprandial serum bile acid concentrations were high in 8 of 10 dogs, and 2-hour postprandial serum bile acid concentrations were high in 9 of 10 dogs. Two of 4 dogs tested had resting plasma ammonia concentrations greater than 200 mg/dl. An ammonia tolerance test was performed on 2 other dogs; both had ammonia concentration greater than or equal to 200 mg/dl in the plasma 30 minutes after receiving 100 mg of ammonium chloride/kg of body weight, PO. Nine dogs died, 1 was euthanatized, and necropsies were performed on these 10 dogs. Biopsies and necropsies of 6 dogs revealed chronic hepatic fibrosis with nodular regeneration (cirrhosis). One dog had hepatocellular carcinoma and mild cirrhosis. In 1 dog, after phenobarbital had been withheld, necropsy revealed complete recovery of the previously observed lesions.
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PMID:Hepatotoxicity of phenobarbital in dogs: 18 cases (1985-1989). 174 13

Fibrin glue is a topical biological adhesive, the effect of which imitates the final stages of coagulation. The glue consists of a solution of concentrated human fibrinogen which is activated by the addition of bovine thrombin and calcium chloride. The resultant clot aids haemostasis and tissue sealing and is completely absorbed during wound healing without foreign body reaction or extensive fibrosis. The fibrinogen component of fibrin glue can be produced from fresh frozen plasma obtained from single unit donations thereby reducing the risks of transfusion transmitted infections encountered by exposure to pools from large numbers of donors. Methods involving precipitation of fibrinogen by cryoprecipitation, polyethylene glycol or ammonium sulphate have been described and evaluated. The risk of transmission of infection can be further reduced by using plasma from 'accredited donors' who are plasma donors regularly tested for ALT and markers of viral infection or by use of fibrinogen prepared in advance of surgery from autologous blood. The second component, a mixture of thrombin and CaCl2, is quantitatively and qualitatively well defined and commercially available (Armour Pharmaceutical Co., Thrombinar (bovine thrombin]. Thrombin is applied to the operation site simultaneously and in equal volume to the fibrinogen but from a separate syringe. In the UK a commercial heat treated fibrin glue prepared from pooled plasma is available on a doctor/named patient basis (Tisseel, Immuno, Vienna). The haemostatic and adhesive properties of fibrin glue can be employed in virtually every surgical specialty. The usefulness of the glue is particularly well documented in the fields of cardiovascular surgery, ENT and neurosurgery.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Fibrin glue. 178 83

49 women of reproductive age were included in the study and were divided in 2 groups. The ovulation inhibitor group (OI) consisted of 37 women aged 33.5-39 exposed to ovulation inhibitors for an average of 13.4 years (Ovosiston, Sequenzovosiston, Non-Ovlon), and the control group consisted of 12 women aged 35.5-41.5 who had taken no OI for at least 5 years. Aspartate-aminotransferase (serum glutamic oxaloacetic transaminase=SGOT) and alanine aminotransferase (serum glutamic pyruvic transaminase) enzymes were determined as indicators of liver damage, and gamma-glutamyl-transferase (gamma-GT) for indication of cholestasis or as a sensitive parameter of hepatopathy. By using a nonradiating, stabile isotop-marked tracer substance, 15 N-ammonium chloride, the uric acid synthesis performance and the ammonium excretion of the liver could be evaluated. The Q-value indicated an excess of ammonium and uric acid as demonstrated by the 15 N test. Significant differences were found between the 2 groups with regard to ALAT, gamma-GT, Q-value, and leukocyte count. The measured values of enzymes and leukocytes studied, however, stayed within the normal range. In the OI group, the decreased gamma-GT activity was surprising. Also, the Q-value showed a slightly pathological median value in 18 women of the OI group. In 4 women who has Q-values of 1.6 to 1.9 (vs. 1.4 median value), liver punction was performed. In each case, liver damage could be shown to be attributed to use of contraceptives. Morphological changes indicating enhanced detoxification activity, and liver cell fat formation of various severity were also found as uncharacteristic alterations. The described increase of the serum activity of aminotransferase, leucine aminopeptidase, alkaline phosphatase, and gamma-GT were interpreted as the expression of cellular adaptation. Long-term use of hormonal contraceptives influences the metabolism of the liver, whose partial disorder can be detected by the 15 N-ammonium test. Normal ALAT and gamma-GT serum enzyme activity in single cases does not allow conclusions on the behavior of the metabolism of the liver.
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PMID:[Use of the stable nitrogen isotope 15N in assessing liver metabolism in hormonal contraception]. 231 86

Acute liver failure was induced in rats by a single intragastric dose of carbon tetrachloride. This causes hepatic centrilobular necrosis, as indicated by histological examinations, and produces a large increase in the activity of serum alanine aminotransferase. The plasma NH4+ level (mean +/- SEM) was 123 +/- 10 microM in the control group and 564 +/- 41 microM in animals with acute liver failure (each n = 5). 31P nuclear magnetic resonance (NMR) was used to monitor brain cortical high-energy phosphate compounds, Pi, and intracellular pH. 1H NMR spectroscopy was utilised to detect additional metabolites, including glutamate, glutamine, and lactate. The results show that the forebrain is capable of maintaining normal phosphorus energy metabolite ratios and intracellular pH despite the metabolic challenge by an elevated blood NH4+ level. There was a significant increase in the brain glutamine level and a concomitant decrease in the glutamate level during hyperammonaemia. The brain lactate level increased twofold in rats with acute liver failure. The results indicate that 1H NMR can be used to detect cerebral metabolic changes in this model of hyperammonaemia, and our observations are discussed in relation to compartmentation of NH4+ metabolism.
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PMID:Observation of cerebral metabolites in an animal model of acute liver failure in vivo: a 1H and 31P nuclear magnetic resonance study. 235 29

Various parameters were investigated to know whether a viability assay before liver transplantation was possible. Two series of experiment were performed. The first consisted of 2 groups of ischemically injured canine livers which had definitely different viability. GPT, bilirubin, lactate pyruvate ratio, ketone body ratio ammonium in the perfusate, hepatic tissue flow, and hepatic tissue oxygen consumption were measured during hypothermic machine perfusion at 6 degree C. As a result, tissue flow and tissue oxygen consumption were found to be good parameters because they indicated the viabilities of the isolated liver grafts accurately and instantly in the both groups. In the second series, 9 ischemically injured canine livers were hypothermically perfused to assay their viability and orthotopically transplanted. In the cases that the oxygen consumption was below 3.0 mumol/min./100g, no grafts sustained the lives of the recipients. We concluded that if we measure the oxygen consumption of hypothermically perfused livers, we can eliminate the low viability livers before transplantation and avoid primary graft non-function.
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PMID:[Viability assay for liver transplantation]. 259 4


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