Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMINOTRANSFERASES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1978

The purification and properties of the aspartate aminotransferase and aromatic-amino-acid aminotransferase from Escherichia coli.

A simple and convenient procedure is described for the isolation in good yield of two amino-transferases from various strains of Escherichia coli. On the basis of their substrate specificities one of the enzymes has been classified as an aromatic amino acid aminotransferase and the other as an aspartate aminotransferase, but both act on a wide range of substrates. Pyridoxal phosphate is bound more strongly to the aspartate aminotransferase than to the aromatic amino transferase which cannot be fully re-activated after removal of the prosthetic group. Both enzymes are composed of two subunits which appear to be identical.

Amino Acids↗
PubMed1999

The ratio of aspartate aminotransferase to alanine aminotransferase: potential value in differentiating nonalcoholic steatohepatitis from alcoholic liver disease.

OBJECTIVE: The ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT) is often greater than 2:1 in alcoholic hepatitis. The purpose of this study was to determine whether this ratio may be used to distinguish nonalcoholic steatohepatitis (NASH) from alcoholic liver disease. METHODS: Patients with NASH were matched with controls with alcoholic liver disease based on age, gender, and date of diagnosis. The diagnosis of alcoholic liver disease was based on exclusion of other causes and a significant history of alcohol consumption. The diagnosis of nonalcoholic steatohepatitis was based on exclusion of other causes of liver disease and a liver biopsy showing > 10% steatosis and inflammation. The two sided Student t test was used for statistical analysis. RESULTS: From 1990 to 1996, 70 patients with NASH were matched with 70 subjects with alcoholic liver disease. Patients with NASH had a mean AST to ALT ratio of 0.9 (range 0.3-2.8, median 0.7) and subjects with alcoholic liver disease a mean ratio of 2.6 (range 1.1-11.2, median 2.0). The mean AST levels were 66 U/L and 152 U/L, and the mean ALT levels 91 U/L and 70 U/L, in the nonalcoholic steatohepatitis and alcoholic liver disease groups, respectively. Although the absolute aminotransferase levels were significantly different in the two groups (p < 0.05), the greatest difference was observed in the AST to ALT ratio (p < 0.000001). Subset analysis of patients with NASH revealed mean AST to ALT ratios of 0.7, 0.9, and 1.4 for subjects with no fibrosis, mild fibrosis, or cirrhosis, respectively. The differences among these ratios were statistically significant (p < 0.05). CONCLUSIONS: The AST to ALT ratio appears to be a useful index for distinguishing nonalcoholic steatohepatitis from alcoholic liver disease. Although values < 1 suggest NASH, a ratio of > or = 2 is strongly suggestive of alcoholic liver disease.

Alanine Transaminase↗
PubMed1975

[Histochemical evidence of aminotransferases. II. Localization of aminotransferases in the medulla spinalis and metencephalon of the rat (author's transl)].

The cytochemical and topochemical localization of 10 aminotransferases have been studied in a serial slices through the spinal cord, medulla oblongata, pons and cerebellum of the rat. In the gray matter a high enzyme activity was observed. The reaction product was localized in the cells and the surrounding neuropil. The cell nuclei were found negativ. In some nuclei aminotransferase activity was higher in the neurons than in the neuropil. In the other nuclei there were no recognizable differences in staining intensity between the neurons and the neuropil. The nerve cells of spinal cord and reticular formation, nuclei n. hypoglossi and n. facialis, nucl. vestibularis lateralis and the Purkinje cells exhibited particularly high aminotransferase activity.

Alanine Transaminase↗
PubMed1982

[Practical use of the Multistat III centrifuge analyzer in an improved method for the determination of the activity of aspartate aminotransferase and alanine aminotransferase].

We applied three procedures for measuring aspartate aminotransferase and alanine aminotransferase activities to the Multistat III MCA. Assay conditions were almost exactly as prescribed by the Scandinavian Committee on Enzymes and the International Federation of Clinical Chemistry. Owing to the overall good performance of the analyzer and its loader module, results of 20 samples will be available in 10 minutes, including preincubation with pyridoxal phosphate. Details of procedures are given; there are no differences in activities of both aminotransferases determined with three methods, allowing the user to take a choice according to personal preference.

Alanine Transaminase↗
PubMed1998

Characterisation of Saccharomyces cerevisiae ARO8 and ARO9 genes encoding aromatic aminotransferases I and II reveals a new aminotransferase subfamily.

The ARO8 and ARO9 genes of Saccharomyces cerevisiae were isolated by complementation of the phenylalanine/tyrosine auxotrophy of an aro8 and aro9 double-mutant strain that is defective in aromatic aminotransferase I (aro8) and II (aro9). The genes were sequenced, and deletion mutants were constructed and analysed. The expression of ARO8 and ARO9 was studied. The deduced amino acid sequences of Aro8p and Aro9p suggest that the former is a 500-residue, 56168-Da polypeptide and the latter a 513-residue, 58516-Da polypeptide. They correspond, respectively, to Ygl202p and Yhr137p, two putative proteins of unknown function revealed by systematic sequencing of the yeast genome. We show that aromatic aminotransferases I and II are homologous proteins, members of aminotransferase subgroup I, and, together with three other proteins, they constitute within the subgroup a new subfamily of enzymes specialised for aromatic amino acid and alpha-aminoadipate transamination. ARO8 expression is subject to the general control of amino acid biosynthesis. ARO9 expression is induced when aromatic amino acids are present in the growth medium and also in aro8 mutants grown on minimal ammonia medium. An autonomously replicating sequence (ARS) element is located between the ARO8 gene and YGL201c which encodes a protein of the minichromosome maintenance family.

2-Aminoadipic Acid↗
PubMed1998

Inhibitory effect of ethanol administration on beta-alanine-2-oxoglutarate aminotransferase (GABA aminotransferase) in disulfiram-pretreated rats.

Ethanol in the presence of disulfiram (N,N,N',N'-tetraethylthiuram disulfide, an inhibitor of aldehyde dehydrogenase) inhibited liver beta-alanine-oxoglutarate aminotransferase (beta-AlaAT I) activity yet activated tyrosine aminotransferase (TAT) in weanling rats in vivo. The effect on beta-AlaAT I was followed by the inhibitory expression of beta-AlaAT I mRNA. The beta-AlaAT I activity was reduced with a pseudo-first-order profile with time, and the half-life was calculated to be 12.3 +/- 0.83 h with the rate constant (Kd) of 0.056 +/- 0.004 h-1. The synthesis of beta-AlaAT I in rat liver was estimated to be 1.56 x 10(-10) mol/g of wet tissue per hour at a steady state. A combination of ethanol and disulfiram also reduced beta-alanine-pyruvate aminotransferase (beta-AlaAT II) activity to 60% of the control after 24 h.

4-Aminobutyrate Transaminase↗
PubMed1975

[Histochemical evidence of aminotransferases. III. Localization of aminotransferases in the mesencephalon, diencephalon, cortex cerebri and in the peripheral nervous system (author's transl)].

The histochemical distribution of some aminotransferases at various levels through the midbrain and cerebrum and in the peripheral nervous system of the rat has been described. The selective localization of the reaction product in the neurons and the neuropil was the same for the aminotransferases studied. There was a difference in the intensity of the enzyme activity. The white matter was negative, and only the glial cells and the blood vessels exhibit transaminase activity. Some nuclei showed an intensive reaction in the neurons and neuropil: nuel. ruber, substantia nigra, hypothalamic nuclei, Ammon's horn. A high activity was observed in the ganglion cell, and the nerve fibres were negative. There was a great similarity between the pattern of distribution for aminotransferases and that for some dehydrogenases.

Animals↗
PubMed2003

Validity and clinical utility of the aspartate aminotransferase-alanine aminotransferase ratio in assessing disease severity and prognosis in patients with hepatitis C virus-related chronic liver disease.

BACKGROUND: The aspartate aminotransferase-alanine aminotransferase ratio (AST/ALT ratio) has been used to noninvasively assess the severity of disease in patients with chronic liver disease (CLD). We previously demonstrated that progressive liver functional impairment is associated with an increase in the AST/ALT ratio. OBJECTIVES: To evaluate the reproducibility and transportability of the AST/ALT ratio in a large cohort of patients with different degrees of hepatitis C virus (HCV)-related CLD, to confirm the correlation between progressive impairment of liver function and increase in the AST/ALT ratio, to evaluate whether diagnostic accuracy of the ALT/AST ratio can be improved by using it with other biochemical variables, and to assess the 1-year prognostic capability of the AST/ALT ratio in patients with liver cirrhosis. PATIENTS AND METHODS: We retrospectively evaluated 252 patients with HCV-related CLD. The AST/ALT ratio was correlated with the degree of liver fibrosis in patients with chronic hepatitis and with the Child-Pugh score in patients with cirrhosis. All patients had undergone monoethylglycinexylidide (MEGX) testing to evaluate liver function. We assessed the prognostic ability of the AST/ALT ratio in a subset of 63 cirrhotic patients who were followed up for at least 1 year. RESULTS: The AST/ALT ratio was more frequently 1 or higher in cirrhotic patients (P<.001). There was a significant correlation between MEGX values and the AST/ALT ratio (r(s) = -0.621, P<.001). Multivariate stepwise logistic analysis showed that AST/ALT ratio, platelet count (PLT), MEGX values, and prothrombin activity were independently associated with the presence of cirrhosis. Combined assessment of the AST/ALT ratio and/or PLT obtained 97.0% positive predictive value and 97.9% negative predictive value for the diagnosis of cirrhosis. The AST/ALT ratio had 81.3% sensitivity and 55.3% specificity in identifying cirrhotic patients who died within 1-year of follow-up. CONCLUSIONS: The AST/ALT ratio is both reproducible and transportable in patients with HCV-related CLD. The AST/ALT ratio is correlated with both histologic stage and clinical evaluation. Progressive liver functional impairment is reflected by an increase in the AST/ALT ratio. Noninvasive evaluation by means of the combined AST/ALT ratio and PLT assessment misclassifies only a few cirrhotic patients. In cirrhotic patients, the AST/ALT ratio provides medium-term prognostic information that is no different from that provided by established prognostic scores.

Alanine Transaminase↗
PubMed2004

Effect of low-zinc status and essential fatty acids deficiency on the activities of aspartate aminotransferase and alanine aminotransferase in liver and serum of albino rats.

The effects of dietary deficiencies of zinc and essential fatty acids (EFAs) or both on aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were investigated in young growing rats. Four groups of albino rats were fed diets deficient in either EFA (4% hydrogenated coconut oil) or zinc (6 ppm) or both. The control diet was adequate in EFA (4% soybean oil) and zinc (100 ppm). The feeding trial lasted eight weeks and the activities of AST and ALT were determined in the liver and serum. EFA deficiency had no significant (p > 0.05) effect on liver AST. However, zinc and the double deficiencies depressed AST activity in the organ. Deficiencies of EFA, zinc and their combination depressed ALT activity in the liver significantly (p < 0.05) with a concomitant increase recorded in the serum. The data suggested alteration in endothelial permeability of the plasma membrane and thus leakage of membrane constituents in the tissue studied. It is therefore considered that these deficient diets may affect liver tissue negatively in view of the role of these enzymes in amino acid metabolism.

Alanine Transaminase↗
PubMed1987

The characteristic pattern of aspartate aminotransferase and alanine aminotransferase in the bitch with the cystic hyperplasia-pyometra complex: effect of medical or surgical treatment.

In 75 clinically normal unspayed female control dogs between two and eleven years old the average plasma level of aspartate aminotransferase (AST) was 21.6 +/- 5.7 (+/- SD) IU/l, of alanine aminotransferase (ALT) 40.4 +/- 13.0 IU/l and of the AST/ALT ratio 0.6 +/- 0.2. These values showed only minor changes over years. In 96 bitches with the cystic hyperplasia-pyometra complex there was a very significant increase of the AST, decrease of the ALT and increase of the AST/ALT ratio. The changes were more pronounced in 62 clinically ill bitches with typical endometritis post oestrum, in 18 dogs with gram negative organisms in the uterus and in 53 bitches with white blood cell (WBC) levels higher than 40 X 10(9)/1. Renal failure had no influence on the specific changed values. The changed values returned either temporarily to normal after prostaglandin (PGF2 alpha)-treatment or definitely after ovariohysterectomy.

Alanine Transaminase↗
PubMed1978

Effect of some--SH and other reagents on aspartate aminotransferase and L-alanine aminotransferase of Paramphistomum explanatum Fischoeder, 1901.

Studies on aspartate aminotransferase (GOT) and L-alanine aminotransferase (GPT) of Paramphistomum explanatum have shown that GPT activity has more than twice the activity of GOT. The effect os some--SH reagents like cadmium, mercury, silver and iodoacetamide revealed that both enzymes were inhibited except that GOT was insensitive to cadmium ions. GPT was found to be much more sensitive to--SH reagents than GOT. There was unusual reaction to the two thiols used, cysteine and mercaptoethanol. Cysteine inhibited both the enzymes and mercaptoethanol activated GPT and inhibited GOT. Thiols in combination with iodoacetamide showed that the strong inhibitory effect of cysteine on both enzymes was reduced by iodoacetamide, but with mercaptoethanol the inhibitory effect on GOT was greater than when either of them was used alone, while GPT the effect of either counteracted each other. EDTA activated both enzymes and partially protected mercury inhibition of both enzymes and silver inhibition GOT only. It provided no protection against silver inhibition of GPT but complete protection of GPT against total inhibition by cadmium ions.

Alanine Transaminase↗
PubMed1988

The influence of long-term anticonvulsant therapy with diphenylhydantoin and carbamazepine on serum gamma-glutamyltransferase, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase.

In 110 patients receiving long-term anti-convulsant monotherapy with diphenylhydantoin (DPH) and carbamazepine (CBZ) the serum activities of gamma-glutamyltransferase (gamma-GT), aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase (AP) were examined retrospectively. Elevated serum levels of gamma-GT and AP were seen in 91% and 39% of patients receiving DPH therapy compared to 64% and 14% of those receiving CBZ treatment. With all enzymes evaluated increases were more frequent and higher with DPH treatment than with CBZ. Frequency and extent of increased activity of gamma-GT were highly related to daily dosage in both preparations. The proportion of pathological enzyme levels was associated with age in DPH and CBZ therapies but not found to be significant. Sex differences in the frequency of increased enzyme activities could not be demonstrated. The results are discussed in the context of induction of the cytochrome P-450 system.

Adult↗
PubMed1977

Suitability of commercial enzyme control sera for the quality control of activity determinations of L-aspartate aminotransferase and L-alanine aminotransferase in human serum.

Details of a systematic approach to suitability testing of commercial control sera are given for substrate optimized L-aspartate aminotransferase and L-alanine aminotransferase methods at 37 degrees C. Their acceptability for control purposes of standardized methods depends on: (1) the range of control values in relation to borderline values, (2) stability, (3) aspect, clarity, (4) NADH consumption in preincubation time, (5) blank activities, (6) kinetic data as half saturation constants and saturation curves, (7) influence of effectors, (8) isoenzyme pattern. These evaluation criteria are proposed for suitability testing. The term "representativeness" should be introduced as a special criterion for main characteristics of control materials. The authors want to point out the close connection with standardization of methods.

Absorption↗
PubMed1981

On the pyridoxal-5'-phosphate stimulation of aspartate aminotransferase and alanine aminotransferase in serum and erythrocytes of patients undergoing chronic haemodialysis and with kidney transplants.

Aspartate aminotransferase (AST) determinations in erythrocytes of patients undergoing chronic haemodialysis and with kidney transplants showed that patients receiving vitamin B6 had a smaller relative stimulation rate of AST by pyridoxal-5'-phosphate (P-5-P). In contrast to these results in erythrocytes, the apoAST and apo-alanine aminotransferase (ALT) activities in serum were increased in patients as compared with those of healthy persons. The corresponding relative stimulation rates of AST and ALT by P-5-P addition to the reaction mixture were not changed in the haemodialysis patients, but in renal transplant recipients the relative stimulation rate of AST was significantly smaller and that of ALT was greater.

Alanine Transaminase↗
PubMed1982

[In vitro supplementation of pyridoxal phosphate for the optimisation of the determination of the catalytic activity of alanine aminotransferase and aspartate aminotransferase in kidney transplant patients (author's transl)].

Pyridoxal phosphate (PLP) is the coenzyme of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Thus, in vitro supplementation with PLP is important for the optimisation of the determination of catalytic activity of both enzymes. It patients with kidney transplants, stimulation by PLP is very important for ALT activity, which could be affected by plasma PLP deficiency. Furthermore, in this population catalytic activities are more frequently found increased using methods with PLP supplementation than without PLP supplementation (56% and 71% of patients for AST and ALT, respectively). These differences are not related to HBs antigen.

Adolescent↗
PubMed2006

Capillary electrophoresis with electrochemiluminescence detection for measurement of aspartate aminotransferase and alanine aminotransferase activities in biofluids.

A new sensitive assay for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in biofluids was developed, based on the separation and detection of alanine, glutamate, and aspartate using capillary electrophoresis (CE) with electrochemiluminescence (ECL) detection. The three amino acids were separated in 5 mM phosphate of pH 2.1 as background electrolyte, and detected on a 500 microm platinum disk electrode at 1.2V (versus Ag/AgCl) in the presence of 10 mM tris(2,2'-bipyridyl)ruthenium(II) dissolved in 80 mM phosphate of pH 10.5. A mass detection limit of 37.3 fmol (or 81.5 fmol) for glutamate, corresponding to the product in the enzyme reaction catalyzed by 1.24 x 10(-9)U AST (or 2.72 x 10(-9)U ALT) in a 30 min reaction period, was achieved. This assay was applied to investigate the cytotoxicity effect of ethanol on HepG2 cells and differentiating nonalcoholic steatohepatitis (NASH) from alcoholic liver disease, indicating that the technique is promising for the application in the cell biological and clinical fields.

Alanine↗
PubMed1988

Evaluation of commercially formulated aspartate aminotransferase and alanine aminotransferase activity determinations by the Scandinavian Committee on Enzymes and IFCC methods as modified for use with automated enzyme analysers.

The performance characteristics of the Scandinavian Committee on Enzymes (SCE) methods for the assay of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were determined using six automated enzyme analysers. The reagent formulation did not include pyridoxal phosphate (PLP). An optimal operating mode was defined for each instrument and precision was assessed in greater detail on four instruments. A points rating system was devised to place the instruments in the following order of proficiency: IL Multistat III, LKB-8600, Gilford 3500, ABA 100. In contrast to AST, the ALT activity of patient samples was unstable at -20 degrees C over periods as short as seven days. The performance characteristics of the IFCC methods for assay of AST and ALT activities were determined by using three automated enzyme analyzers in order to assess the effect of PLP upon precision and activity of four quality control sera, and to compare the SCE and IFCC methods. Precision of AST assays did not alter on omission of PLP from the IFCC formulation, while that of ALT assays showed slight deterioration. The decrease in activity on omitting PLP was variable with each instrument. A points-rating system was devised to place the methods in the following order of precision: AST: IFCC (-PLP) 118, IFCC 109, SCE 61; ALT: IFCC 125, IFCC (-PLP) 97, SCE 66. The IFCC methods offer better precision, and the overall change on omitting PLP is minimal.

Alanine Transaminase↗
PubMed1996

Activities of glycogen phosphorylase, alanine aminotransferase and aspartate aminotransferase in adult worms of Litomosoides carinii recovered from pyridoxine deficient cotton rats (Sigmodon hispidus).

This paper demonstrates that the activities of glycogen phosphorylase (GP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are reduced in adult worms of the filarial nematode Litomosoides carinii recovered from pyridoxine-deficient cotton rats when compared to worms recovered from pyridoxine-sufficient controls. GP, ALT and AST activities were determined in adult worms L. carinii recovered from cotton rat hosts over a 20-week experimental period. Activities of GP, ALT and AST in the parasite showed a direct correlation with the dietary pyridoxine intake of their host. Throughout the experiment, enzyme activities were significantly lower (P < 0.001) in worms from rats fed a pyridoxine-free diet ad libitum that in worms from rats fed either a stock colony diet, a pyridoxine-free diet ad libitum with daily supplementation of 100 micrograms pyridoxine or limited amounts of pyridoxine-free diet with daily supplementation of 100 micrograms pyridoxine. The lower than normal activity of GP, ALT, AST and other enzymes dependent on the biologically active derivative of pyridoxine, the coenzyme pyridoxal-5-phosphate (PLP), interferes with the protein, carbohydrate and lipid metabolism of L. carinii and may in part cause the reduced establishment, development and growth of the parasite in pyridoxine-deficient hosts.

Alanine Transaminase↗