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

Clinical application of the extracorporeal liver perfusion has been rather limited mainly because of cumbersome procedure, not infrequent circulatory insufficiency due to large priming volume, and bleeding tendency due to hepatic insufficiency itself and heparinization, which are inherent with most of the currently available systems. A circuit was developed which employs siliconized tubings to eliminate heparinization. The liver is gravity perfused added with arterial pressure by utilizing A-V type blood access, thus eliminating the blood pump and oxygenator. A heat exchanger is eliminated by placing the liver in a moist liver chamber kept at 30 degrees C. Feasibility of the circuit was confirmed by 5 in vivo runs with healthy mongrel dogs who tolerated the procedure well. This circuit was further evaluated in dogs with acute hepatic failure induced by portacaval anastomosis and subsequent ligation of the proper hepatic artery 48 hours later. They were connected to the circuit when convulsion developed. Along with clinical observation, biochemical analysis were performed for samples obtained at the inlet (In-blood) and the outlet (Out-blood) of the liver chamber. Oxygen consumption with carbon dioxide production by the liver was confirmed in previous control experiment. Although temporarily, all animals showed recovery from convulsion. Ammonia level was invariably lower in Out-blood than in In-blood by approximately 70 gamma/dl. Blood sugar level was always higher in Out-blood by 40-70 mg/dl than in In-blood. Other parameters such as bilirubin, total protein, GOT and GPT levels were not significantly different. Technical feasibility and acceptable performance of the system were established in this study and its clinical evaluation is warranted.
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PMID:[Experimental studies on extracorporeal liver perfusion.--Development and evaluation of an improved circuit (author's transl)]. 73 Jan 6

1. Adult rats were subjected to a brief period of diethyl ether anaesthesia and were given diets with 200 or 100 g casein/kg with or without arginine plus glycine supplementation in the post-anaesthesia period. Nitrogen retention was measured as well as liver protein content and liver and muscle transaminase activities (L-aspartate aminotransferase (GOT), (EC 2.6.1.1), and L-alanine aminotransferase (GPT)(EC 2.6.1.2). 2. Results demonstrated that anaesthesia-stressed rats consuming the high-protein diet with supplemental arginine and glycine retained twice as much N as did rats given the diet with 200 g casein/kg alone, for the first 5 d post-anaesthesia. 3. Anaesthesia-stressed animals consuming the diets with 100 g casein/kg with or without arginine plus glycine supplementation did not differ from each other in N retention. 4. Liver protein content increased after anaesthesia in rats given the high-protein diets; liver transaminase activity increased, whereas muscle transaminase activity decreased, in animals consuming the high protein diets. 5. Possible mechanisms to account for these results are discussed.
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PMID:Nitrogen retention in rats fed on diets enriched with arginine and glycine. 2. Effect of diethyl ether anaesthesia on N retention. 85 75

Gyrocotyle fimbriata isolated from the spiral valve of Hydrolagus colliei were washed, then held in a filtered seawater-penicillin-Tris buffer medium. Ammonia and urea release to the medium declined together and ammonia production was minimal when the urea concentration was below detectable limits. Alanine and smaller amounts of glycine were released to the medium at a more constant rate. After 12 hr the alanine-glycine excretion was more than 20 times the ammonia excretion. L-arginine, L-serine, L-histidine, and urea were most effective in stimulating ammonia production by whole worms; other L-amino acids were essentially ineffective. L-glutamate dehydrogenase, L-amino acid oxidase, uricase, and ornithine transcarbamylase were below detectable levels. L-serine dehydrase, L-arginase, L-histidase, and urease were detected in tissue homogenates and probably account for most of the endogenous ammonia production. L-arginase has a molecular weight of 28,000 by Sehpadex gel filtration. The high levels of glutamate-pyruvate transaminase and lower levels of glutamate-oxalacetate transaminase correlate with the high level of alanine excretion. It is concluded that (1) ammonia production is not strongly linked to the overall energy metabolism of Gyrocotyle and is probably a result of a series of unrelated enzymatic reactions such as the action of urease of urea from the tissue of the rat fish, and (2) alanine and glycine are the major nitrogen excretory products and their production is linked to the energy metabolism of Gyrocotyle.
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PMID:Ammonia formation and amino acid excretion by Gyrocotyle fimbriata (Cestoidea). 111 78

L-Leucine-pyruvate transaminase obtained from Acetobacter suboxydans exhibited absorbance maxima to 280 and 332 nm. The 332 nm peak was derived from the coenzyme bound to the enzyme protein with the epsilon NH2 of a lysine residue. The transaminase showed reactivity against many L-amino acids. The relation between the reactivity and the structure of the amino donor is discussed. The Michaelis constants for L-leucine, pyruvate, L-alanine and alpha-ketoisocaproate were 6.7, 3.1, 7.1 and 0.9 mM, respectively. The equilibrium constant was 5.3. The activation energy at pH 5.0 was 8,800 cal/mol.
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PMID:Further characterization of L-leucine-pyruvate transaminase from Acetobacter suboxydans. 115 85

The only exogenous substrates oxidized by mitochondria isolated from the flight muscle of the Japanese beetle (Popillia japonica) are proline, pyruvate and glycerol 3-phosphate. The highest rate of oxygen consumption is obtained with proline. The oxidation of proline leads to the production of more NH3 than alanine, indicating a functioning glutamate dehydrogenase (EC 1.4.1.2). Studies of mitochondrial extracts confirm the presence of a very active glutamate dehydrogenase, and this enzyme is found to be activated by ADP and inhibited by ATP. These extracts also show high alanine aminotransferase activity (EC 2.6.1.2) and a uniquely active "malic' enzyme (EC 1.1.1.39). The "malic' enzyme is activated by succinate and inhibited by ATP and by pyruvate. It is suggested that the input of tricarboxylate-cycle intermediate from proline oxidation is balanced by the formation of pyruvate from malate, and the complete oxidation of the majority of the pyruvate. Studies of the steady-state concentrations of mitochondrial CoASH and CoA thioesters during proline oxidation show a high succinyl (3-carboxypropionyl)-CoA content which falls on activating respiration with ADP. There is a concomitant rise in CoASH. However, the reverse transition, from state-3 to state-4 respiration, causes only very slight changes in acylation. The reasons for this are discussed. Studies of the mitochondrial content of glutamate, 2-oxoglutarate, malate, pyruvate, citrate and isocitrate during the same phases of proline oxidation give results consistent with control at the level of glutamate dehydrogenase and isocitrate dehydrogenase during proline oxidation, with the possibility of further control at "malic' enzyme. During the oxidation of pyruvate all of the tricarboxylate-cycle intermediates and NAD(P)H follow the pattern of changes described in the blowfly (Johnson & Hansford, 1975; Hansford, 1974) and isocitrate dehydrogenase is identified as the primary site of control.?2OAuthor
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PMID:The nature and control of the tricarboxylate cycle in beetle flight muscle. 120 Sep 85

We report a 41-year-old male of citrullinemia associated with argininosuccinate acid synthetase deficiency. He was admitted to the Hitachi General Hospital because of finger tremor, restlessness and urinary incontinence. He had short stature and a poor appetite. Laboratory evaluation was summarized as follows: mild hypoglycemia, low plasma cortisol levels, delayed response of 17-OHCS and 17-KS to ACTH administration in urine, and delayed response of plasma ACTH level to insulin administration. In this case, ACTH deficiency is estimated to be a dysfunction of the hypothalamus. Replacement therapy of hydrocortisone improved his symptoms. He was readmitted to the hospital because of delirium and confusion, two weeks after the hydrocortisone administration. At that time, he had flapping tremor. Laboratory examination revealed hyperammonemia (NH3: 231 micrograms/dl) and mild elevation of GOT and GPT. Serum and urinary amino acid determination showed marked elevation of citrulline (478.1 nmol/ml in serum, 4681.2 mumol/day in urine). Lactulose administration, low protein diet and plasmapheresis were started, but he went into a coma. Without any improvement, he died on the 29th hospital day. Autopsy examination of the liver disclosed fatty change. Adrenal cortex depicted severe atrophy. Biochemical analysis of urea cycle enzymes of the liver and kidney showed decreased activity of argininosuccinate synthetase (liver: 0.0022 U/mg protein, 5% of that normal liver, kidney: 0.003 IU/mg protein, 20% of that in normal kidney). Citrullinemia associated with ACTH deficiency have not reported in the literature. It may be presumed that ACTH deficiency is concerned with the delayed onset of hyperammonemia. The relation between citrullinemia and endocrinological abnormalities is also discussed.
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PMID:[A case of citrullinemia associated with isolated ACTH deficiency, rapidly developing coma]. 133 25

We have previously reported that Drosophila Kc cells require glutamine for maximal expression of heat shock proteins in stressed conditions (Sanders and Kon: J. Cell. Physiol. 146:180-190, 1991). The mechanism of this effect has been investigated by comparing the metabolic utilization of glutamine in conditions which support hsp expression with that of glutamate in conditions where up to 100-fold less hsp is synthesized. This comparison showed that free ammonia was generated by cells incubated in the presence of glutamine in 37 degrees C (heat shock) conditions, but not at 25 degrees C, and not in the presence of glutamate in either normal or heat shock conditions. There was no difference in the amount of [14C]O2 generated from either [14C]-labeled amino acid in the tricarboxylic acid cycle, but three- to four-fold more alanine was synthesized in cells incubated in glutamine than in glutamate. Treating the cells with aminotransferase inhibitors to artificially increase NH3 release raised hsp expression in the presence of glutamate to maximal levels characteristic of glutamine. This potentiation correlated with inhibition of alanine aminotransferase. Since only NH3 production correlated with hsp expression in heat shock conditions in the presence of glutamine, and NH3 addition to glutamate also resulted in maximal hsp expression, we measured glutamine production in glutamate plus NH3 and observed net glutamine synthesis. The supposition that glutamine itself is responsible for the regulatory changes supporting maximal hsp expression was supported by the finding that the glutamine analog, 6-diazo-5-oxo-L-norleucine (DON), mimicked the effects of glutamine. We conclude that glutamine imposes regulatory changes which alter nitrogen metabolism and support hsp expression in Kc cells.
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PMID:Glutamine and glutamate metabolism in normal and heat shock conditions in Drosophila Kc cells: conditions supporting glutamine synthesis maximize heat shock polypeptide expression. 134 46

A hybrid protein between staphylococcal protein A and human lymphotoxin, ALT, was produced in Escherichia coli by expression of a recombinant plasmid containing the respective genes. IgG-binding activity of ALT was confirmed by Western blotting analysis and by affinity purification with IgG-Sepharose column chromatography. The purified ALT had cytotoxicity on mouse L-929 cells and its specific activity was approximately 3.5-5.0 X 10(6) U mg-1. ALT was partially degraded by a protease including in the E. coli lysate or trypsin and was converted to lymphotoxin which lacks the NH2-terminal 19 residues but possesses higher cytotoxic activity than ALT.
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PMID:Production of a protein A--lymphotoxin hybrid protein for cancer-targeted therapy. 136 61

The effect of O-phenanthroline (OP) on mechlorethamine hydrochloride (HN2) toxicity was studied in in vitro and in vivo experiments. Incubation of HN2 with the in vitro rat liver slice system resulted in leakage of alanine aminotransferase (ALT) in a time-dependent manner. Exposure of the slices to HN2 for 4 h caused 79.2% ALT leakage. In the presence of OP enzyme leakage was reduced to 28.7%. OP-induced protection was shown to be dose dependent. Other metal chelators such as dithiothreitol (DTT) and EDTA (ethylenediaminetetraacetic acid) had a weak effect on HN2 cytotoxicity. The protective activity of OP was also demonstrated in in vivo skin toxicity studies in the guinea pig. The ulcerative effect of topically applied HN2 was inhibited by OP even when applied 10 min following the alkylator. Histology of NH2-treated skin showed epidermal ulceration associated with a covering layer of encrusted exudate. However, only a slight diffuse acanthosis of the epidermal layer was observed when OP was applied for 10 min after the vesicant. It is suggested that OP may be used for the prevention of tissue damage caused by antineoplastic treatment with nitrogen mustard. It might also be employed in military medicine as an antidote to the chemical weapon sulfur mustard.
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PMID:Protective effect of O-phenanthroline against mechlorethamine toxicity in the rat liver slice system and in the guinea pig skin. 174 67

At sublethal concentrations, cypermethrin caused a decrease in total proteins and an increase in free amino acids, protease, alanine aminotransferase and aspartate aminotransferase in liver, brain and gill tissues of Tilapia mossambica. Nitrogen metabolic profiles like ammonia, urea and glutamine were also elevated in all the tissues as a consequence of cypermethrin toxicity. Glutamate dehydrogenase, AMP deaminase and adenosine deaminase activity was also increased in the present study.
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PMID:Cypermethrin induced changes in nitrogen metabolism of fish, Tilapia mossambica. 187 79


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