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)

Mitochondrial aspartate aminotransferase is synthesized on free polysomes as a higher molecular weight precursor (Sonderegger, P., Jaussi, R., Christen, P., and Gehring, H. (1982) J. Biol. Chem. 257, 3339-3345). The present study examines whether the coenzyme pyridoxal phosphate or pyridoxamine phosphate is required for the uptake of the precursor into mitochondria. Chicken embryo fibroblasts were cultured in medium prepared with and without pyridoxal. In cells grown in the presence of pyridoxal only holoform of aspartate aminotransferase and no apoenzyme was detected. Cells cultured under pyridoxal deficiency contained about 30% of apoenzyme in secondary cultures. All of this apoform was identified as mitochondrial isoenzyme. In order to differentiate whether this apoenzyme corresponded to newly synthesized protein or originated from pre-existing holoenzyme, double isotope-labeling experiments were performed. Secondary cultures of chicken embryo fibroblasts grown under pyridoxal depletion were labeled with [3H]methionine, and then pulsed with [35S]methionine. In another series of experiments, the 3H-labeled cells were pulsed with [35S]methionine in the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone in order to accumulate the precursor. Subsequently, the accumulated precursor was chased into the mitochondria by addition of the carbonyl cyanide m-chlorophenylhydrazone antagonist cysteamine. The holo- and apoenzyme from the ultrasonic extract of the double-labeled cells were separated by affinity chromatography on a phosphopyridoxyl-AH-Sepharose column, immunoprecipitated, and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Under both experimental conditions, the 3H/35S ratio of the apoenzyme was less than half of that of the holoenzyme. Therefore, the apoenzyme and not the holoenzyme is the first product of the precursor in the mitochondria. Apparently, the precursor of mitochondrial aspartate aminotransferase is transported into mitochondria as apoprotein and is processed there independently of the coenzyme.
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PMID:The precursor of mitochondrial aspartate aminotransferase is translocated into mitochondria as apoprotein. 373 49

beta-Sulfopyruvic acid (2-carboxy-2-oxoethanesulfonic acid) is prepared in greater than 90% yield by reaction of bromopyruvic acid with sodium sulfite. beta-[35S]Sulfopyruvate is prepared by transamination between [35S]cysteinesulfonate (cysteate) and alpha-ketoglutarate using mitochondrial aspartate aminotransferase isolated from rat liver. Following either chemical or enzymatic synthesis, the crude reaction product is conveniently purified by chromatography on Dowex 1; beta-sulfopyruvate is isolated as the stable, water-soluble dilithium salt. beta-Sulfopyruvate is shown to be an alternative substrate of mitochondrial malate dehydrogenase; in the presence of 0.25 mM NADH, beta-sulfopyruvate is reduced with an apparent Km of 6.3 mM and a Vmax equal to about 40% of that observed with oxaloacetate. This finding forms the basis of a convenient spectrophotometric assay of beta-sulfopyruvate.
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PMID:beta-Sulfopyruvate: chemical and enzymatic syntheses and enzymatic assay. 374 Apr 6

In male albino rats tocopherol acetate and sodium selenite were shown to be efficient in treatment of isoniazide-induced liver damage. The disturbances of secretion of bile, bile acids and bilirubin and excretion of cholesterol were less pronounced. A decrease of the activity of marker blood serum enzymes--alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase--also indicated the hepatoprotective effect of these drugs. The intensity of lipoperoxidation indicated by a decrease of lipid peroxidation indices in the liver and blood was diminished. Tocopherol acetate and sodium selenite increase the number of sulfhydryl groups but decrease the number of disulfide groups in these biosubstrates.
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PMID:[Antioxidant effectiveness in isoniazid-induced lesions of the liver]. 375 39

One goat anesthetized with thiamylal sodium, xylazine, and halothane for repair of an abominal hernia, and 7 of 29 goats similarly anesthetized for an experiment unrelated to considerations of anesthesia, developed signs of hepatic failure within 24 hours of anesthesia. Affected goats had high values for serum aspartate transaminase and serum total bilirubin by 12 to 24 hours after induction of anesthesia. Necropsy of the 8 affected goats revealed centrilobular to massive hepatic necrosis (8 of 8), brain lesions consistent with hepatic encephalopathy (3 of 4), and acute renal tubular necrosis (6 of 6). Two unaffected goats had no hepatic necrosis. Causes of hepatic necrosis other than those related to anesthesia (eg, infectious agents, toxins) were ruled out by lack of supporting necropsy findings or were considered unlikely because of lack of opportunity for exposure. Hepatic lesions in these goats closely resembled those described in human beings with halothane-associated hepatic injury, although in both species these lesions are nonspecific at the gross and light microscopic levels. The pathogenesis of halothane-associated hepatic injury in goats, as in human beings, remains to be determined.
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PMID:Hepatic necrosis following halothane anesthesia in goats. 379 99

Biological intra-individual variation in concentrations of 16 clinical biochemical analytes in serum was estimated for 27 patients with insulin-dependent diabetes mellitus (IDDM), and results were compared with those for apparently healthy individuals. In general, the variation was significantly higher in the patients. The ratio of the average intra-individual variation in IDDM patients to that in normal subjects exceeded 2.0 for Na+, K+, creatinine, and alpha-amylase; 1.50 to 2.0 for Cl-, total protein, albumin, cholesterol, and hemoglobin; and 1.2 to 1.5 for urea, uric acid, high-density-lipoprotein cholesterol, and aspartate aminotransferase. This increased variability in IDDM patients may be caused by variations in osmotic diuresis. Average intra-individual variations were greater for women than for men for Na+, total protein, albumin, and hemoglobin. Individual values showed a gaussian distribution for all analytes, including enzymes and triglycerides. No intra-individual variation was time dependent. For practical purposes, decision-making criteria in monitoring IDDM can be derived from the estimated biological component of intra-individual variation and the analytical variation established for each laboratory.
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PMID:Intra-individual variation of some analytes in serum of patients with insulin-dependent diabetes mellitus. 380 96

Serum concentrations of sodium, potassium, chloride, total protein, albumin, aspartate transaminase, creatine kinase, lactate dehydrogenase, gamma-glutamyltranspeptidase, alkaline phosphatase and alanine transaminase were determined in free-living white rhinoceroses Ceratotherium simum (n = 20). Single serum cortisol (n = 20), oestradiol-17 Beta (n = 14) and progesterone (n = 14) concentrations are also presented. Low serum sodium (129.6 +/- 4.2 mmol/l) chloride (94.2 +/- 3.05 mmol/l) and albumin (26.1 +/- 3.71 mmol/l) as well as high globulin (alpha 1, alpha 2, beta and gamma) concentrations were outstanding features.
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PMID:Blood chemical parameters in free-living white rhinoceros Ceratotherium simum. 383 4

In a randomized clinical trial 89 obese patients had end-to-side jejunoileostomy with either a 1:3 or a 3:1 ratio between jejunum and ileum left in continuity. The duration of postoperative observation was at least 36 months. Repeated assessments were made on plasma concentrations of sodium, potassium, bicarbonate, magnesium, calcium, aspartate aminotransferase, and clotting factors. The major findings were that bypass surgery (i) has no important influence on levels of sodium, bicarbonate, and calcium, (ii) induces potassium depletion and transient liver dysfunction of a degree that is independent of the jejunoileal ratio, and (iii) induces a greater magnesium depletion when a long jejunum and short ileum segment are left in continuity.
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PMID:The influence of jejunoileal ratio on plasma electrolytes and liver function in intestinal bypass for morbid obesity. A randomized trial. 388 52

The effects of sodium selenite on bromobenzene hepatotoxicity were examined in male rats. Rats pretreated with sodium selenite (12.5 or 30 mumol/kg, ip) 72 hr prior to injection of bromobenzene (7.5 mmol/kg, ip) showed a marked reduction in bromobenzene-induced liver injury as evidenced by decreased plasma alanine and aspartate transaminase values, sorbitol dehydrogenase activity, and reduced histologic damage. Administration of bromobenzene did not affect the selenium content of blood or liver. At 72 hr after treatment with selenite, hepatic reduced (GSH) and oxidized (GSSG) glutathione values or GSH synthetic and degradation enzyme activities were not altered. However, from 3 to 12 hr following bromobenzene administration, hepatic GSH and cysteine amounts declined less rapidly in selenite-treated rats compared to control. Thus, acute selenite treatment ameliorated bromobenzene hepatotoxicity in a manner suggesting facilitation of hepatic GSH production by selenite for use in bromobenzene detoxication.
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PMID:Effect of sodium selenite upon bromobenzene toxicity in rats. I. Hepatotoxicity. 396 15

Normal reference ranges for sodium, potassium, urea, creatinine, calcium, phosphate, total protein, albumin, bilirubin, alkaline phosphatase, and aspartate transaminase were determined from 344 fetal and maternal plasma samples between 15 and 38 weeks' gestation. Pure fetal blood was obtained by fetoscopy in the second trimester and in the third trimester by umbilical cord puncture at delivery. All biochemical substances were measured by continuous flow (SMAC, Technicon) except albumin, which was measured by turbidimetry (CobasBio, Roche). The resulting data were analysed on an AMDAHL 470A computer and reference ranges covering 2.5 to 97.5 percentiles were defined. Analysis of variance was performed to examine the overall effect of gestational age on the analytes measured and on the changes in the fetal compartment relative to the mothers'. A paired t test was performed to examine how these biochemical substances in fetal plasma related to maternal plasma from the same pregnancy.
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PMID:Normal reference ranges for biochemical substances relating to renal, hepatic, and bone function in fetal and maternal plasma throughout pregnancy. 398 61

Serum levels of sodium, potassium, chloride, phosphorus, iron, total magnesium, total calcium, alkaline phosphatase, alanine transaminase, lactate dehydrogenase, creatine kinase, gamma-glutamyltransferase, aspartate transaminase, urea, creatinine, total protein, albumin and plasma glucose were determined in 49 ostriches (Struthio camelus) kept under semi-extensive conditions.
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PMID:Blood chemical and electrolyte concentrations in the ostrich Struthio camelus. 402 Aug 17


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