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)

1. Factors regulating the release of alanine and glutamine in vivo were investigated in starved rats by removing the liver from the circulation and monitoring blood metabolite changes for 30 min. 2. Alanine and glutamine were the predominant amino acids released into the circulation in this preparation. 3. Dichloroacetate, an activator of pyruvate dehydrogenase, inhibited net alanine release: it also interfered with the metabolism of the branched-chain amino acids valine, leucine and isoleucine. 4. L-Cycloserine, an inhibitor of alanine aminotransferase, decreased alanine accumulation by 80% after functional hepatectomy, whereas methionine sulphoximine, an inhibitor of glutamine synthetase, decreased glutamine accumulation by the same amount. 5. It was concluded that: (a) the alanine aminotransferase and the glutamine synthetase pathways respectively were responsible for 80% of the alanine and glutamine released into the circulation by the extrasplanchnic tissues, and extrahepatic proteolysis could account for a maximum of 20%; (b) alanine formation by the peripheral tissues was dependent on availability of pyruvate and not of glutamate; (c) glutamate availability could influence glutamine formation subject, possibly, to renal control.
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PMID:Factors regulating amino acid release from extrasplanchnic tissues in the rat. Interactions of alanine and glutamine. 0 55

Protein hydrolysate-containing parenteral solutions have been reported to be hepatotoxic. Ten infants who were treated with a 20 percent glucose solution containing either 2.5 percent or 3.25 percent protein hydrolysate are reviewed. Their gestational ages were 30 to 40 weeks and births weights 1000 to 35000 g. Serum glutamate-oxaloacetate transaminase (GOT), glutamate-pyruvate transaminase (GPT), leucine amino peptidase (LAP) and bilirubin were measured serially. Serum amino acids were measured and consistently demonstrated decreased levels of isoleucine and increased aspartic acid, glutamic acid, serine, proline, glycine, alanine, threonine and lysine. The amino acid imbalances were associated with transaminase elevations in eight infants. Serum bilirubin levels increased in six patients and LAP in four. Liver biopsies from three patients showed minimal to moderate hepatic parenchymal disease with cholestasis.
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PMID:The hepatotoxicity of parenteral protein hydrolysate-containing solutions. 82 62

Untrained rats were subjected to a single intense physical effort. In the plasma the activity of alanine aminotransferase, aspartate aminotransferase, and the concentrations of amino acids: glycine, cystine, alanine and leucine with isoleucine were measured. The results were compared with the data obtained in a control group. Despite lack of statistically significant differences in the activity of aminotransferases and concentration of amino acids between these groups a correlation was found between the activity of AIAT and alanine concentration in the animals after exercise. The concentration of alpha-amino nitrogen was decreased statistically significantly in the group of animals subjected to intensive exercise.
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PMID:The effect of a single intense effort on the activity of aminotransferases and concentration of free amino acids in the plasma of rats. 119 42

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

As far as the pathogenesis of poisonings with organophosphorus pesticides is concerned, in addition to irreversible inhibition of acetylcholinesterase (AGE) in tissues, of importance are changes in the other systems which essentially determine the outcome of intoxication. The purpose of the present study was to examine the nature of changes occurring in total protein and protein fractions, free amino acids (aspartic and glutamic acids, glycine, isoleucine, leucine) and in certain enzymes (AST, ALT, CP, GGTP, GDH) in the cerebrospinal fluid (CSF) of patients with acute Malathion insecticide poisoning. 137 patients aged 20 to 50 years were placed under observation. There were 77 men and 60 women. 40 persons had poisoning of medium gravity and 97 were severely poisoned. The intake of the CSF was performed on days 1, 3, 10, 14 and 21 since the disease onset. It has been established that in acute Malathion insecticide poisoning, the CSF content of the stimulating mediator amino acids, aspartic and glutamic, rises within the early periods, whereas the concentration of the inhibitory mediator glycine decreases. The changes in protein fractions of the CSF are characterized by a fall of the content of globulins and a rise of albumins, thus attesting to the predominance of pathological processes in the brain, especially in the initial period of intoxication, and to the impairment of the blood-brain barrier. The development of intoxication is associated with activation in the CSF of LDN, CP, GGTP and GDH as well as by activation of LDH isozymes which is viewed as the result of the membranotoxic effect of a Malathion insecticide.
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PMID:[Changes in the biochemical composition of the cerebrospinal fluid in acute carbophos poisoning]. 135 42

Many modifications of the UW solution have been reported to yield successful results in rat liver preservation and transplantation. One solution used histidine, in combination with lactobionate (HL-I), and gave superior preservation of the rat liver when compared with the UW solution. In this study we have compared the HL-I solution with 90 mM histidine, HL-II solution with 30 mM histidine, and the UW solution in dog liver preservation and transplantation. Dog livers were preserved for 48 hr in one of the three solutions and transplanted. The peak AST and ALT values were highest in livers preserved in HL-I, intermediate in UW solution, and lowest in HL-II. However, there were no significant differences among survival rates (average 5-7 days per group), posttransplant serum concentration of liver enzymes (AST, ALT, LDH, and alk-phos), clotting factors (PT and PTT), bilirubin, and fibrinogen concentration for each group. Dogs were sacrificed or died within 5-7 days due to rejection in nonimmunosuppressed dogs. Also, rat livers were preserved in the HL-II solution or in a solution in which histidine was replaced by isoleucine (IL-I). Isoleucine is an amino acid with a molecular mass similar to that of histidine, but is not as good a hydrogen ion buffer as histidine at the pH used for liver preservation (7.4). The buffer capacity of the IL-I solution was similar to the UW solution, but about one-half as much as the HL-II solution. Rats receiving a liver preserved for 30 hr in HL-II or IL-I were 100% viable. Rats receiving a liver preserved for 40-44 hr in HL-II or IL-I showed less survival (33% and 25%, respectively). This shows that histidine can be effectively replaced by isoleucine in a preservation solution and gives equivalent preservation results. Thus, the mechanism of improvement of liver preservation with histidine is not due to its action as a hydrogen ion buffer. These studies show that, although the HL solutions are superior for preservation of the rat liver, they are not superior to the UW solution for preservation of the dog liver. However, as others have shown in the rat liver transplant model, a simplified UW solution (HL-II) appears effective in dog liver preservation. The dog liver transplant model remains a more appropriate model for testing new preservation solutions prior to initiation of clinical trials.
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PMID:A comparison of histidine-lactobionate and UW solution in 48-hour dog liver preservation. 141 52

The study was performed to evaluate the levels of some enzymes (AST, ALT, HGTP, LDG) and free amino acids (aspartic, glutaminic, glycine, isoleucine, leucine) in liquor of 37 subjects who got poisoned with a Malathion insecticide. Their condition was diagnosed as moderate and severe. The liquor was obtained on poisoning day 1, 3, 10, 14 and 21. The liquor levels of enhancement mediatory amino acids, aspartic and glutaminic, rise early in poisoning, while concentration of inhibition mediator glycine tends to decline. Progress of intoxication brings about a rise in LDG and GGTP activity attributed to a membranotoxic effect of the insecticide.
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PMID:[Various biochemical indicators of the cerebrospinal fluid in acute carbophos poisoning]. 168 19

Four aminotransferases were identified and characterized from Methanococcus aeolicus. Branched-chain aminotransferase (BcAT, EC 2.6.1.42), aspartate aminotransferase (AspAT, EC 2.6.1.1), and two aromatic aminotransferases (EC 2.6.1.57) were partially purified 175-, 84-, 600-, and 30-fold, respectively. The apparent molecular weight, substrate specificity, and kinetic properties of the BcAT were similar to those of other microbial BcATs. The AspAT had an apparent molecular weight of 162,000, which was unusually high. It had also a broad substrate specificity, which included activity towards alanine, a property which resembled the enzyme from Sulfolobus solfataricus. An additional alanine aminotransferase was not found in M. aeolicus, and this activity of AspAT could be physiologically significant. The apparent molecular weights of the aromatic aminotransferases (ArAT-I and ArAT-II) were 150,000 and 90,000, respectively. The methanococcal ArATs also had different pIs and kinetic constants. ArAT-I may be the major ArAT in methanococci. High concentrations of 2-ketoglutarate strongly inhibited valine, isoleucine, and alanine transaminations but were less inhibitory for leucine and aspartate transaminations. Aromatic amino acid transaminations were not inhibited by 2-ketoglutarate. 2-Ketoglutarate may play an important role in the regulation of amino acid biosynthesis in methanococci.
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PMID:Characterization of amino acid aminotransferases of Methanococcus aeolicus. 172 42

In a clinical setting, the effect of Eurocollins (EC) and University of Wisconsin solution (UW) on liver grafts were studied in the early reperfusion phase of liver transplantation. Blood samples were drawn before and after declamping of the portal vein in a group of 11 transplants with EC-perfused livers, and a group of 12 transplants with UW-perfused livers. Parenchymal damage was assessed by the LDH, AST, and ALT, and purine degradation by measuring the uric acid levels. Metabolic function was determined by the serum bile acids and the plasma amino acids, i.e. (valine + leucine + isoleucine)/(phenylalanine + tyrosine) ratio. Donor and pretransplant recipient parameters were almost identical. The cold ischemia time of both groups differed significantly. The results show the following: a significant difference between both the LDH and the uric acid levels in the two groups was revealed, with a smaller increase of the LDH levels and no increase of the uric acid levels in the UW group. Metabolic activity, as measured from the bile acids and the amino acid profile in the peripheral blood, was identical in both groups. We conclude that both EC-stored and UW-stored liver grafts show immediate metabolic function after reperfusion. The amount of metabolic function was equal in both groups, notwithstanding longer cold ischemia time in the UW group. In addition, more parenchymal damage occurred in the EC group.
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PMID:Cellular damage and early metabolic function of transplanted livers stored in Eurocollins or University of Wisconsin solution. 180 31

Twenty obese and 20 lean LA/N-cp male rats and 20 male Sprague-Dawley rats were fed a diet containing either 54 percent sucrose or starch for six weeks. After a 14-16 hour fast, rats were killed. Liver and kidney enzyme activities were determined in the LA/N-cp rats while plasma urea and selected amino acids were determined in all rats. Liver glucose-6-phosphatase (G6PASE), fructose-1,6-bisphosphatase (FBPASE), phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), malic enzyme (ME), glucokinase (GK), pyruvate kinase (PK), phosphofructokinase (PFK), glutamic-oxaloacetic-transaminase (GOT), glutamic-pyruvic transaminase (GPT), arginase (ARGASE), arginine-synthase (ARG-SYN) and ornithine transcarbamylase (OTC) levels were significantly affected by phenotype (obese greater than lean). All the above changes in enzyme levels were exaggerated by sucrose-feeding with the exception of PK, PFK, GOT, GPT, ARGASE and ARG-SYN. Kidney cortex G6PASE, PEPCK and ARGASE activities were higher in the obese rats as compared to the lean littermates. Sucrose feeding resulted in higher cortex G6PASE, FBPASE and PEPCK as compared to starch-fed rats. A phenotype effect was noted with plasma glutamate, urea, leucine, isoleucine and valine (obese greater than lean) and a diet effect was seen with aspartate, phenylalanine, leucine and valine (sucrose greater than starch) concentration. Sprague-Dawley rats had higher plasma urea and lower alanine than lean LA/N-cp males. Metabolic obesity in the LA/N-cp rat appears to involve an elevated capacity for pathways of glycolysis, gluconeogensis, lipogenesis and amino acid catabolism in the liver.
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PMID:Effect of dietary carbohydrate on liver and kidney enzyme activities and plasma amino acids in the LA/N-cp rat. 204 12


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