Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report the presence of complexes between aspartate aminotransferase (AST, EC 2.6.1.1) and immunoglobulin (Ig) in the serum of a patient suffering from lung cancer with metastasis to the liver. After fractionation of the serum by gel filtration, AST-Ig complexes (AST-IgA, AST-IgG) were demonstrated by counterimmunoelectrophoresis. Dissociating the complexes and recombining them with purified isoenzyme fractions, s-AST (cytoplasmic) and m-AST (mitochondrial), revealed that only s-AST binds to IgG, whereas IgA binds to both s-AST and m-AST. Although the association of AST with IgG has been reported, to our knowledge this is the first finding of both AST-IgA and AST-IgG complexes in a patient's serum. Serum AST-IgG complexes have been demonstrated in both healthy and diseased individuals; in the latter category, as reported here and by others, the liver is implicated.
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PMID:Complexes of immunoglobulins A and G with aspartate aminotransferase isoenzymes in serum. 682 50

The distribution of the isoenzymes of aspartate aminotransferase (AST, E.C. 2.6.1.1.) in equine tissues has been studied to ascertain whether the organ of origin may be identified when the total AST activity of serum is raised. Most tissues contain 3 isoenzymes of cytoplasmic origin (cAST) with isoelectric points of 5.6, 5.7 and 5.9, and one isoenzyme of mitochondrial (mAST) origin with an isoelectric point of 9. Serum from horses with azoturia contained an additional cytoplasmic subform with an isoelectric point of 5.8. This form could not be generated by ageing, freezing and thawing or binding of the enzyme to gamma globulins or lipids. The ratio of cAST to mAST when separated by ion exchange chromatography varies widely between tissues, with no cAST detection in lung and no mAST detection in serum. Ageing of equine muscle homogenates caused the formation of 2 artefactual subforms with isoelectric points of 6.0 and 6.1. It is concluded that, although the ratio of mitochondrial to cytoplasmic AST varies between tissues, there is no tissue specificity of either cytoplasmic or mitochondrial isoenzymes and examination of serum would not indicate the source.
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PMID:Observations on the isoenzymes of aspartate aminotransferase in equine tissues and serum. 717 41

When organ damage is assessed from activities of tissue enzymes in plasma, it is assumed that variations in tissue enzyme content, both among individuals and between different sites within an organ, are small. We checked these assumptions, using canine heart and liver. We determined creatine kinase (CK; EC 2.7.3.2), lactate dehydrogenase (LD; EC 1.1.1.27), aspartate aminotransferase (AST; EC 2.6.1.1), and glucosephosphate isomerase (GPI; EC 5.3.1.9) in different sites of different hearts; the results showed CVs of 9.3, 9.1, 13.5, and 8.2%, respectively. A small transmural gradient in CK is found in the left ventricle. Determination of AST, GPI, and alanine aminotransferase (ALT; EC 2.6.1.2) in different sites of different livers gave CVs of 12.5, 17.0, and 11.6%, respectively. Most of the total variation is interindividual. The unreliability of early data and conflicting reports on transmural myocardial enzyme gradients are discussed. We conclude that by use of proper enzymes, such as LD for the heart and ALT for the liver, organ damage can be estimated, although there are inherent problems in relating enzyme release to loss of tissue mass.
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PMID:Distribution of enzymes in dog heart and liver; significance for assessment of tissue damage from data on plasma enzyme activities. 729 36

We examined data from the participants in the Lipid Research Clinics Program Prevalence Study for associations between high-density lipoprotein (HDL) cholesterol and clinical chemistry tests. There is a negative relationship between serum thyroxine and HDL cholesterol: men 20-69 years and women 20-44 years with low thyroxine levels have significantly higher HDL cholesterol than those with high thyroxine levels. Women 45-69 years with hyperglobulinemia (> 3.2 g/dl) have significantly lower HDL cholesterol levels than those with lower globulin levels. There is a weak negative association between HDL cholesterol and serum uric acid in men 20-44 years and a stronger association in women. A weak negative association between HDL cholesterol and plasma glucose is present only in men 20-44 years and women 45-69 years. Subjects with high serum bilirubin or serum aspartate aminotransferase (AST, SGOT) values have higher HDL cholesterol levels that are statistically significant in men 20-69 years and women 20-44 years (bilirubin) and men 45-69 years and women 45-69 years (AST). There is a negative association between alkaline phosphatase and HDL cholesterol in women and young men. These results suggest that thyroid hormones may be involved in the regulation of HDL cholesterol, and that there are associations between HDL cholesterol and the clinical chemistry tests that are not necessarily explained by disease. However, in the whole population, the plasma constituents measured as clinical chemistry tests, or the mechanisms that regulate their levels, are not important determinants of plasma HDL cholesterol levels.
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PMID:Associations of plasma high-density lipoprotein cholesterol with clinical chemistry data. 741 42

The method for continuous-flow assay of aspartate aminotransferase with the Technicon SMAC was modified to include preincubation of the serum enzyme with pyridoxal 5'-phosphate, to be consistent with the recommendations of IFCC and the Standards Committee of AACC. Preliminary estimates of the imprecision of the modified method on SMAC gave day-to-day standard deviations of 5.3 U/L at mean of 48 U/L (n = 66) and 6.2 U/L at 155 U/L (n = 61). Added bilirubin, sodium pyruvate, ascorbic acid, and endogenous lipids did not interfere. Comparison of results for 50 samples by this method with those by the manual IFCC method gave y = 1.1113x - 0.3 U/L, Sy/x = 4.4 U/L, and r = 0.997. Similar data are presented for the revised AST method for the DuPont aca discrete analyzer. Clinical data show that AST activities increase by as much as 200% when the serum is preincubated with pyridoxal 5'-phosphate.
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PMID:Preincubation of serum aspartate aminotransferase with pyridoxal 5'-phosphate in the SMAC: comparison with revised DuPont aca method and recommended IFCC method. 747 32

We have developed a new multienzyme control serum, Seraclear-HE, which was designed to function not only as an accuracy and precision control serum but also as an intermethod calibrator for unifying interlaboratory clinical enzyme data in terms of reference method values. Seraclear-HE contains as analytes the following enzymes of human origin only: aspartate aminotransferase (AST, EC 2.6.1.1) and lactate dehydrogenase (LD, EC 1.1.1.27) from erythrocytes; alanine aminotransferase (ALT, EC 2.6.1.2) from a hepatoma cell line; alkaline phosphatase (ALP, EC 3.1.3.1) from an amnion cell line; creatine kinase (CK, EC 2.7.3.2) from an embryo kidney cell line; gamma-glutamyltransferase (GGT, EC 2.3.2.2) from a macrophage cell line; and amylase (AMY, EC 3.2.1.1) from urine and saliva. The seven partly purified enzymes were lyophilized in partially delipidated human serum containing sucrose (50 g/L), pyridoxal 5'-phosphate (30 mmol/L), and other stabilizers. The material is stable for at least 2 years at temperatures < or = 10 degrees C. For two concentrations of this preparation, reference method values (mainly International Federation of Clinical Chemistry and Japan Society of Clinical Chemistry) obtained at both 30 degrees C and 37 degrees C are assigned.
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PMID:Multienzyme control serum (Seraclear-HE) containing human enzymes from established cell lines and other sources. 1: Preparation and properties. 753 43

Previous studies from Spain, Italy, and France have demonstrated a high prevalence (71% to 91%) of antibodies against hepatitis C virus in patients with porphyria cutanea tarda (PCT). To determine the role of hepatitis C virus (HCV) in PCT in Germany, we have assessed the prevalence of antibodies against HCV and hepatitis B virus (HBV) in 106 patients (mean age, 60 +/- 14 years) with the disease. Eight of 106 patients (8%) were positive for HCV antibodies and HCV RNA using second-generation enzyme-linked immunosorbent assay (ELISA), recombinant immunoblot assay, and polymerase chain reaction. Antibodies against HBV core antigen were found in 14 patients (13%). Of the patients with antibodies against HCV alanine transaminase (ALT) (aspartate transaminase [AST]) levels above normal occurred in 71% (86%). Because elevated ALT (AST) levels were also found in 51% (64%) of 88 patients without markers of HCV or HBV, we suggest that liver damage in PCT may exist in absence of these viruses. This is supported by the finding that in patients without HCV or HBV markers, higher serum ALT and AST activities were found in patients with overt disease or relapse (ALT, 59 +/- 44 U/L; AST, 37 +/- 21 U/L), whereas patients in remission displayed significantly lower serum enzyme activities (ALT, 16 +/- 8 U/L; AST, 16 +/- 7 U/L), (P < .001). These results indicate that HCV infection does not play a major role in the pathogenesis of PCT in Germany.
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PMID:Low prevalence of hepatitis C virus infection in porphyria cutanea tarda in Germany. 753 93

The effects of strenuous physical exercise on the serial changes in the haematological, biochemical and hormonal markers were investigated. A group of 14 soldiers, aged 24-36 years, took part in a military training course for about 13 weeks. After severe exercise stress, an increase (90%) in the number of peripheral blood leucocytes was observed. The degree of leucocytosis showed a close correlation with the values of some serum parameters, such as concentrations of aspartate aminotransferase (AST; r = 0.747), lactate dehydrogenase (LD; r = 0.748), blood urea nitrogen (r = 0.756), creatine kinase (CK; r = 0.637), manganese-superoxide dismutase (Mn-SOD; r = 0.508), alanine aminotransferase (ALT; r = 0.542) and uric acid (r = 0.538), and concentrations of urinary parameters, such as vanilmandelic acid (r = 0.429) and free cortisol (r = 0.437). The subjects showing prominent leucocytosis over 9500 cells.microliters-1 exhibited a lower concentration of serum cholinesterase than those who showed milder leucocytosis. The serum Mn-SOD concentration was closely correlated with the serial changes in serum concentrations of AST, ALT, LD and CK, indicating exercise-induced muscle and liver damage. The change in peripheral leucocyte number was assumed to be diagnostically informative and may be a prognostic marker, reflecting organ damage and restoration after strenuous physical exercise.
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PMID:Leucocytosis as a marker of organ damage induced by chronic strenuous physical exercise. 878 93

We investigated whether bile salts (BS) with different hydrophobic-hydrophilic properties interact with ethanol on bile secretion, enzyme (aspartate transaminase [AST], lactate dehydrogenase [LDH]) release in the perfusate, liver ultrastructure, and vesicular exocytosis in the isolated perfused rat liver. Ethanol (0.1 or 1%) promoted a rapid decrease of bile flow and BS secretion in livers perfused with taurocholate (TCA), the physiologic BS in the rat (-28% decrease of baseline values with 0.1% and -34% with 1% ethanol). The inhibitory effect of ethanol on bile flow and BS secretion was significantly (P < .02) attenuated by perfusing liver with the hydrophilic BS, tauroursodeoxycholate (TUDCA), and it was exacerbated (P < .02) by perfusion with the hydrophobic BS, taurodeoxycholate (TDCA). The release of AST and LDH in the perfusate was unaffected by 0.1% ethanol, but increased threefold to fivefold by 1% ethanol in TCA-perfused livers. This cytolitic effect of ethanol was not observed in TUDCA-perfused livers, but it was enhanced (P < .03) by perfusion with TDCA. No ultrastructural abnormalities were found in either TCA- or TUDCA-perfused livers, with or without 1% ethanol. Only minimal changes were found in livers perfused with TDCA alone, but, in the presence of TDCA, 1% ethanol induces marked mitochondrial damage. The biliary excretion of the fluid phase marker horseradish peroxidase was inhibited by ethanol, an effect reversed by TUDCA (P < .02) and exacerbated by TDCA (P < .04). In conclusion, this study demonstrates that hydrophilic BS such as TUDCA counteract the inhibitory effect of ethanol on bile secretion and vesicular exocytosis as well as the ethanol-induced cytolitic effect in the isolated perfused rat liver. In the presence of hydrophobic BS such as TDCA, the exposure to ethanol promotes a marked inhibition of bile secretion and vesicular exocytosis as well as prominent mitochondrial damage.
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PMID:Functional and ultrastructural features of ethanol/bile salts interaction in the isolated perfused rat liver. 770 87

Plasma CK concentrations have been widely used as the primary muscle enzyme marker for diagnosis and progression of myositis. Recently, total CK and CK-MB serum concentrations have been compared to, and used in conjunction with, serum concentrations of aspartate aminotransferase in diagnosis of myositis. The algorithmic use of CK, AST, and aldolase plasma concentrations to diagnose and categorize patients with myopathy may be a useful method of diagnosing specific muscle disease without invasive procedures. CAIII, as a specific marker for skeletal muscle damage, may replace CK as the enzyme of choice in diagnosis and progression of myositis and other muscle disease. Additional studies are required to determine the usefulness of carbonic anhydrase for the diagnosis and assessment of myositis.
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PMID:Evaluation of laboratory tests as a guide to diagnosis and therapy of myositis. 785 25


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