Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.6.1.1 (aspartate aminotransferase)
21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aspartate aminotransferase (AST, EC 2.6.1.1) exists in human tissues as two distinct isoenzymes, one located in the cytoplasm (c-AST), and the other in mitochondria (m-AST). Striated muscle, myocardium, and liver tissues are the main sources of AST. A growing body of information suggests that determination of AST isoenzymes in human serum is useful in evaluating damage to some of these organs. In hepatic disease, the test is used to assess liver necrosis and for determining prognosis. It may also assist in identifying patients with active alcoholic liver disease. In patients with acute myocardial infarction, measurement of AST isoenzymes provides diagnostic information that differs from that obtained by determination of total creatine kinase and lactate dehydrogenase enzymes, and their isoenzymes.
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PMID:Aspartate aminotransferase isoenzymes. 222 56

Fifty consecutive liver transplants were performed using livers perfused with and stored in University of Wisconsin preservation solution. These grafts were compared with the preceding 55 consecutive transplants performed using livers perfused and preserved with Eurocollins solution. The purpose of the study was to determine if organs preserved with UW solution functioned better after transplantation than organs preserved with Eurocollins. Extensive retrospective analysis of prospectively accumulated data included enzyme levels through 30 days, cost and length of hospital stay, blood product usage, and ischemia time. Average age of patients in the UW group was 47.1 years compared with 39.6 years in the EC group (P less than 0.05); cold ischemia time was 7.21 hr in the UW group compared with 5.21 in EC (P = 0.0001). Total bilirubin values were significantly lower on days 0-6 and day 14, but not day 30, in the UW group. Aspartate aminotransferase was significantly lower in the UW group on days 0-1, 3-6, and 14, but not on day 3 or day 30. Prothrombin times were significantly lower in the UW group across all times (days 0-6, 14, and 30). Intraoperative and postoperative use of packed red blood cells and fresh frozen plasma was lower in the UW group (P less than or equal to .05). Also, total hospital days, intensive care unit days, and hospital cost to the patient were lower in the UW group (P less than or equal to .05). A second analysis was done comparing only nonemergent transplants from both groups. These results confirmed the initial analysis of a longer cold ischemia time in the UW group (P less than 0.001), and improved enzyme values in the TBR, AST, and PT in the UW group (P less than 0.05). Also, hospital cost in the UW group was again lower (P less than 0.05). In this nonrandomized study, the cold ischemia time was increased but kept close to that of the control group. We conclude that UW solution is an improved donor liver preservation solution on the basis of improved enzyme values, decreased blood usage, shorter hospital stay, and lower hospital charges.
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PMID:A comparison of UW with Eurocollins preservation solution in liver transplantation. 236 Feb 52

Aminotransferase activities were measured in the serum of two- to three-year-old Thoroughbred fillies and colts during a four week period of peak training for flat racing. Aspartate aminotransferase (AspAT, EC 2.6.1.1), mitochondrial aspartate aminotransferase (m-AspAT) and alanine aminotransferase (AlaAT, EC 2.6.1.2) activities in serum were measured and the relative proportions of apoenzyme and holoenzyme were determined. The aminotransferase activities were increased only slightly immediately following exercise. This small and immediate post exercise increase in activity did not vary greatly over the period of peak training. Measured in the presence of exogenous pyridoxal 5'-phosphate, mean enzyme activities (iu/litre at 30 degrees C) before exercise were: AspAT, 291; m-AspAT, 13; AlaAT, 18. After exercise they were: AspAT, 317; m-AspAT, 16; AlaAT, 23. Nearly all of the AspAT activity was present in the holoenzyme form (94 per cent holoenzyme) indicating excellent vitamin B6 status in these animals. Paradoxically, the AlaAT in serum from the same highly trained Thoroughbred horses was poorly saturated with pyridoxal phosphate, with nearly half of the AlaAT in most horses present in the inactive apoenzyme form (61 per cent that of holoenzyme). It is critical therefore, that exogenous pyridoxal phosphate be included in aminotransferase assays to determine the amounts of enzyme release into the peripheral circulation.
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PMID:Effects of exercise on serum amino-transferase activity and pyridoxal phosphate saturation in Thoroughbred racehorses. 236 10

Twenty-eight Norwegian Red Cattle dairy cows were fed silage ad libitum and restricted amounts of concentrates. Blood samples were collected before morning feeding, once or twice weekly, from 2 weeks before to 12 weeks after calving. Parameters of liver function, carbohydrate status and fertility were recorded in order to assess their interrelationships. Eight cows were treated for clinical ketosis. Four of these had to be treated 2 or 3 times. Aspartate aminotransferase and bilirubin showed the highest within-animal coefficients of correlation with acetoacetate. Analysis of variance revealed a significant effect of carbohydrate status (indicated by plasma acetoacetate levels) on the levels of aspartate aminotransferase, glutamate dehydrogenase and sorbitol dehydrogenase, though only a small part of the total variation was explained by this factor. The estimated volume density of liver fat in the 4th week of lactation averaged 6.0 +/- 6.4% (+/- SD) ranging from 0.1-25.1%. Liver fat content at this stage of lactation was not significantly correlated with other indicators of liver function or carbohydrate status. Cows treated for clinical ketosis had significantly lower plasma progesterone values at the time of first ketosis treatment than untreated multiparous cows. The frequency of high progesterone values (greater than 3 ng/ml) being significantly lower in treated than in untreated cows during the period from 3-5 weeks post partum, though not at later stages. In conclusion, the results revealed a significant relationship between carbohydrate status and liver function, and also between clinical ketosis and luteal function.
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PMID:Variations in parameters of liver function and plasma progesterone related to underfeeding and ketosis in a dairy herd. 259 86

Aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, and alkaline phosphatase activities in the blood serum of women taking the oral contraceptive preparation Microgynon through extended periods were raised; the activity of cholinesterase was simultaneously reduced. In rats liver homogenates ethynylestradiol, one of the active components of Microgynon, acted as an inducer of gamma-glutamyltransferase and alkaline phosphatase while leaving aspartate aminotransferase and alanine aminotransferase unaffected, but reduced the level of cholinesterase. Norgestrel, the other active component of the preparation, suppressed the biosynthesis of gamma-glutamyltransferase and alkaline phosphatase while leaving aspartate aminotransferase, alanine aminotransferase and cholinesterase levels unaffected. A mixture of ethynylestradiol plus norgestrel in the mass proportion occurring in Microgynon produced the same effects upon gamma-glutamyltransferase and alkaline phosphatase as ethynylestradiol alone. Estradiol, the parent hormone of ethynylestradiol, lacked the inducing capability of the latter while ethynylpropargyl chloride induced gamma-glutamyltransferase and alkaline phosphatase so it was concluded the inducing effect of ethynylestradiol must be ascribed to the ethynyl radical. Progesterone, the parent of norgestrel, shared the latter's suppressive activity for gamma-glutamyltransferase and alkaline phosphatase biosynthesis, and behaved like its derivative towards the other enzymes.
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PMID:Changes of activities of some transferases, alkaline phosphatase and cholinesterase in the blood of women using oral contraceptives and in vitro influence of these agents on tissular enzyme levels in rat liver. 260 59

The excitatory amino acids, aspartate and glutamate, have been proposed as retinal neurotransmitters. Aspartate aminotransferase (AAT) is an enzyme which is involved in the routine metabolism of these amino acids and may be involved in the specific synthesis of glutamate and/or aspartate for use as a neurotransmitter. On the basis of the hypothesis that increased levels of aspartate aminotransferase may reflect a transmitter role for aspartate and/or glutamate, we have localized aspartate aminotransferase in the guinea pig and cynamolgus monkey retinas with light and electron microscopic immunohistochemical techniques. AAT-like immunoreactivity is localized to the cones of guinea pig retina and to monkey rods. Both species contain a subpopulation of immunoreactive amacrine cells as well as a subpopulation of immunoreactive cells in the ganglion cell layer. Immunostaining is seen in bipolar cells and terminals in the monkey but not in the guinea pig retina. We have performed quantitative analysis of the immunoreactive staining in the outer plexiform layer and described the synaptic organization of immunoreactive processes in the inner plexiform layer (IPL). Labeled amacrine processes in both species form synaptic contacts predominantly to and from bipolar terminals in the inner third of the IPL and to and from other amacrine and small unidentified processes in the outer portion of the IPL. The majority of labeled bipolar terminals in the monkey retina are seen in the inner third of the IPL where they synapse exclusively onto amacrine processes. Labeled bipolar terminals in the outer third of the IPL occasionally synapse onto ganglion processes.
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PMID:Aspartate aminotransferase-like immunoreactivity in the guinea pig and monkey retinas. 285 36

Forty six children suffering from Protein Energy Malnutrition (PEM) were classified according to the Wellcome classification. Their aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transferase were measured. Aspartate aminotransferase was raised in 20 patients (43.5%) and alanine aminotransferase was raised in 12 patients (26%). Y-glutamyl transferase was raised in only one patient suffering from marasmic kwashiorkor, who, in contrast to the rest of the patients had a marked rise in aminotransferases. The aminotransferase elevation correlated positively with a Severity Index calculated from height and weight retardation and serum albumin levels. It is suggested that the moderate rise in aminotransferases found in PEM is not due to damage to the liver. However, marked enzyme elevations can occur in a small minority of patients, suggestive of liver injury, probably caused by hepatotoxins.
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PMID:Serum aminotransferases and gamma-glutamyl transferase in protein energy malnutrition. 286 77

Twenty horses of various ages had inadvertently ingested alfalfa hay contaminated with Senecio vulgaris. Among them, 4 died of liver disease. Blood was collected from affected horses at monthly intervals for 7 months and at the 9th and 14th months. The following serum enzymes and chemical items were assayed: aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, gamma-glutamyl transferase, sorbitol dehydrogenase, total bilirubin, BUN, glucose, cholesterol, inorganic phosphate, calcium, total protein, and albumin. Amino acid profiles, conjugated bile acids, sulfobromophthalein clearance times, and liver histopathologic changes via serial biopsies were also monitored. Liver histopathologic changes revealed lesions progressively increasing in severity. Aspartate aminotransferase and plasma amino acid ratios indicated chronic liver degeneration (0.05 level of significance). gamma-Glutamyl transferase and lactate dehydrogenase as well as BUN values fluctuated, but returned to within reference values. Horses appeared clinically normal 14 months after intoxication, but were unable to tolerate stress of exercise.
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PMID:Clinicopathologic study of horses surviving pyrrolizidine alkaloid (Senecio vulgaris) toxicosis. 287 83

Glutamate and aspartate are putative excitatory neurotransmitters in the central nervous system. The present study utilized novel monoclonal antibodies against fixative-modified glutamate and aspartate and polyclonal antisera against the amino acid synthesizing enzymes, glutaminase and aspartate aminotransferase, to analyze the distribution of these amino acids in the rodent midbrain periaqueductal gray. Glutamate-, aspartate-, glutaminase- and aspartate aminotransferase-like immunoreactive neurons, fibers and processes are present throughout the rostrocaudal length of the periaqueductal gray. Glutamate- and glutaminase-like immunoreactive neurons displayed a similar homogeneous pattern of distribution, being localized predominantly to the lateral and dorsal subdivisions of the periaqueductal gray. Co-localization experiments suggest that glutamate and glutaminase are in fact co-contained within the same PAG neurons. Aspartate aminotransferase-like immunoreactive neurons were distributed in a pattern similar to glutamate and glutaminase with the exception that fewer cells were stained in the dorsocaudal and the rostral third of the PAG. Aspartate-like immunoreactive neurons were less numerous than glutamate-like immunoreactive cells and were located in the lateral aspect of the PAG. These results demonstrate a specific and distinct distribution of glutamate and aspartate immunoreactive neurons and support recent data suggesting that glutamate and aspartate serve as excitatory neurotransmitters in the PAG.
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PMID:Localization of glutamate, glutaminase, aspartate and aspartate aminotransferase in the rat midbrain periaqueductal gray. 288 81

Beating rat heart cultures were prepared in vitro and infected with Coxsackie B-2 virus. The cells were evaluated in the post-infected period for changes in cardiac enzymes, alterations in beating frequency and cytotoxicity as measured by chromium 51 (51Cr) release. The cardiac enzymes, lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) were measured in infected and uninfected controls over a period of 120 h. Enzyme levels in the infected cells remained essentially the same for the first 42 h as compared to the controls. At this time, the LDH levels increased rapidly reaching 116 +/- 24.8 U/l while the controls remained at 46.9 +/- 9.7 U/l. Aspartate aminotransferase levels increased at a slower rate and obtained a level of 104 +/- 20.2 U/l compared to 66.6 +/- 13.2 U/l in the control. Visual evidence of cellular damage as measured by decreased beating frequencies and the appearance of cytopathic effect was first noted at 42 h post-infection. Complete loss of cardiac beats and maximal viral cytopathic effect occurred at 96 h post-infection. Cardiac cellular damage as measured by cytotoxicity assay was found to parallel those changes seen in cardiac enzymes. No significant changes in cytotoxicity were observed for the first 24 h; however, at 48 h increased release of 51Cr was noted and visual evidence of viral replication also was present. The cardiac enzyme changes noted in beating rat heart cells appear to be similar to those changes reported in patients with viral-induced myocardial disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Coxsackie B-2 virus infection in rat beating heart cell culture. 300 12


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