Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.6.1.2 (alanine aminotransferase)
 26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:Effect of some--SH and other reagents on aspartate aminotransferase and L-alanine aminotransferase of Paramphistomum explanatum Fischoeder, 1901. 41 89

Changes in the protein metabolism of gill, kidney and intestine of freshwater fish, Cyprinus carpio exposed to 1, 15 and 30 days to sublethal concentration (0.1 mg/l) of mercury were studied. The total, soluble and structural protein contents recorded the depletion followed by progressive increase in accumulation of free aminoacids. Concurrently, the activity of protease in the tissues was also increased. A steady enhancement in the activities of aspartate aminotransferase and alanine aminotransferase paralleled the elevation of glutamate dehydrogenase activity in the organs studied. Levels of ammonia and urea have also reported elevation. All these changes clearly documented the induction of severe proteolysis. The magnitude of these changes increased overtime. These changes were more in the gill at the initial periods of exposure (1 and 15 days), but as the period of exposure increased, these changes were more pronounced in the kidney at 30 days of exposure to sublethal concentration of mercury.
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PMID:Shifts in protein metabolism in some organs of freshwater fish, Cyprinus carpio under mercury stress. 193 Feb 54

1. Rosy barb (Puntius conchonius) were exposed to 181 micrograms/l mercuric chloride for 48 h and the activity of acid and alkaline phosphatases (AcP and AIP), aspartate aminotransferase (AAT), alanine aminotransferase (AIAT), lactic dehydrogenase (LDH), and acetylcholinesterase (AchE) were measured in vivo in several organs. 2. The AcP activity was inhibited in the liver, gills, kidneys, and gut but stimulated in the gonads. With the exception of kidney, the AIP activity showed an increase in all the organs examined. The AAT and AIAT were generally inhibited in different organs. An increase in LDH activity occurred in the cardiac and skeletal muscles while the AchE activity was considerably lowered in the brain, gills, and liver. 3. In vitro exposure to mercury at concentrations ranging between 10(-10) and 10(-4) M, inhibited the AIP, AAT, AIAT, LDH, and AchE activities in the tissues examined. The AcP activity was also depressed in all the tissues except in the testes, in which a marginal increase was noted. 4. The in vivo and in vitro effects of Hg were not of similar quality implying sequestration of toxic cations in the intact animals.
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PMID:Use of the fish enzyme system in monitoring water quality: effects of mercury on tissue enzymes. 198 72

Alanine aminotransferase has been stabilized by using chemical modification with both bis(imidates) (of varying length) and succinic anhydride. The voltammetric behavior of the native enzyme and its various modified forms has been studied by using both cyclic voltammetry and differential pulse adsorptive voltammetry. A distinctive accumulation pattern was found for each of the stabilized enzymes at the static mercury drop electrode with respect to the native alanine aminotransferase. Adsorptive voltammetry was demonstrated to be a useful technique to assess the extent of chemical modification of this enzyme, which is indirectly related to their stability for use in biotechnological processes. The sue of differential pulse adsorptive voltammetry, after a preconcentration of the enzyme for 300 s at the electrode surface, has yielded a detection limit of 1.0 x 10(-9) M.
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PMID:Application of adsorptive voltammetry to assess the stability of modified alanine aminotransferases. 236 Jul 13

This work was designed to study effects of HgSO4 on rabbits performance when added in the mash diet for 7 weeks with concentrations of 0, 150, and 300 ppm as Hg (6 animals/group). The Hg application caused mortality associated with diarrhoea, haemorrhage, oedema and liver and stomach necrosis. The contaminated diets caused significantly increased feed intake, drinking water consumption and live body gain. Mercury did not affect organ percentages significantly (P greater than or equal to 0.05). Serum analyses reflected a significant (P less than or equal to 0.05) rise in the glucose content (for the animals fed the 300 ppm Hg-diet) with a slight decrease in Ca level and activity of both transaminases GPT and GOT. The most affected organ by the application of Hg was the liver which reflected a slight increase in its dry matter substance, significant increase (P less than or equal to 0.01) in the ether extract percentage on the 300 ppm Hg-diet and severe reduction (P less than or equal to 0.01) in its vitamin A as well as in the iron content (P less than or equal to 0.05) on the 300 ppm Hg-diet. The highest level of Hg added caused an increase (P less than or equal to 0.01) in bone magnesium.
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PMID:Effect of dietary contamination with mercury on the performance of rabbits. 342 34

Rats were treated with HgCl2 and/or alcohol per os in a standard diet as to get a chronic intoxication. Histological and ultrastructural examination of the liver, GPT, GOT, LDH enzymatic activities, and toxicological mercury evaluation were performed. Liver cell degenerative changes with focal necrosis, and structural alteration and fibrosis were demonstrated in the group of rats treated with HgCl2. The combined administration of HgCl2 and alcohol did not result in more advanced lesions, even if steatosis could be demonstrated in the liver. An increase of the GPT, GOT and LDH enzymatic activities was demonstrated in the rats of both groups but it was higher in the rats treated with HgCl2 and alcohol combined. On the contrary, the liver and kidney mercury storage was higher in the rats treated with HgCl2 alone.
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PMID:[Experimental chronic poisoning by mercury and alcohol: histopathologic, ultrastructural findings and toxicologic and enzymatic evaluations]. 689 38

The toxic effects of cadmium (Cd) and mercury (Hg), as chloride salts, were studied using an hepatic human fetal cell line (WRL-68 cells). From viability curves and the proliferative capacity of the cell in the presence of the metal, three different cell treatments were chosen, (1) 0.5 microM of the metal chloride for 24 h (acute low dose treatment), (2) 0.5 microM of the metal chloride for 7 days (chronic treatment), and (3) 5 microM of the metal chloride for 24 h (acute high dose treatment). WRL-68 cells grown in the presence of Cd exhibited the same proliferative curve as control cells, whereas in the case of Hg, the cells increased their proliferative capacity. Both metals produced ultrastructural alterations in different degrees, mainly observed as mitochondrial and RER structural changes, depending of the treatment and concentration of the metal used. Cytotoxicity was assessed by measuring the release of lactate dehydrogenase from the cells. Acutely high dose-treated cells showed the highest value for this parameter, and Cd-treated cells presented higher lactate dehydrogenase release than the Hg-treated ones. Cell damage was also measured by alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) activities. Acute high dose Cd treatment caused the highest value of enzymatic release. Lipid peroxidation was significantly different with respect to control cells in chronic and acute high dose treatments with both metals. Metallothionein (MT) induction in response to Hg treatment was not detected. However, a dramatic induction of this protein occurred in Cd-treated cells. WRL-68 cells differentially respond to Cd and Hg making this hepatic fetal human cell line a useful tool in investigating the mechanism of toxicity of these heavy metals.
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PMID:Cadmium and mercury toxicity in a human fetal hepatic cell line (WRL-68 cells). 748 68

Problems with the assessment of organ damage caused by toxic substances in places of residence have recently appeared with increasing frequency. In spite of this there have been so far no uniform, objective research methods which could allow their accurate evaluation. This is why the attempt has been made to assess morphological and functional condition of the liver in patients chronically exposed to mercury compounds in the place of settlement. The research group consisted of 62 patients exposed to metallic mercury at a yearly rate exceeding 24 kg for average duration of 16 years. Patients with the liver or biliary tract diseases, symptoms of chronic circulatory insufficiency, Australia (HBs+) antigen carriers and alcoholics were excluded from the research group. The control group consisted of 29 males. AST and ALT activity, prothrombin level, bilirubin and protein concentration in blood serum were measured and scintigraphic and USG examinations of the liver were performed. Mercury concentrations were also established. Scintigraphic examination yielded an abnormal image of the liver in 52% of the exposed patients. The differences in frequency and intensity of scintigraphic changes in comparison with the control group were of statistical significance. No pathological changes were found in USG examination. Significantly higher ALT activity and bilirubin concentration and significantly lower total protein concentration were found in the exposed group. The correlation between the intensity of scintigraphic changes and mercury concentration were noted. Liver scintigraphic examination combined with biochemical analysis allows an assessment of the liver condition in chronic exposure to mercury compounds in the place of settlement.
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PMID:The assessment of the condition of the liver in patients chronically exposed to mercury compounds in the place of settlement. 764 91

The serum immunoglobulin (IgG, IgM and IgA) concentrations of 44 mercury-exposed workers were examined and compared with those of non-exposed, age- and sex-matched individuals. At the time of testing, the exposed population had a mean (+/- S.D.) mercury urinary concentration of 24.7 +/- 19.1 and in 40 of them urinary mercury levels were below the currently accepted limit of 50 micrograms/g creatinine. Increased IgG, IgA and IgM levels were found in the mercury-exposed individuals and in 16, a second evaluation was performed six months later. During the intervening six months, the level of hygiene was improved throughout the plant, and urinary mercury concentrations were determined monthly in each worker. Despite a significant reduction in mercury urinary concentrations, serum immunoglobulin levels did not return to the normal range. There was no correlation between the length or level of exposure and the immunoglobulin levels. Liver protein synthesis, as studied by factor V, prothrombin time, prealbumin and transaminase activity, was normal and liver injury, as evaluated by serum aspartate and alanine aminotransferase activities (AST and ALT, respectively), was not observed. No haematological abnormalities were noted. These results indicate that "safe" levels of mercury exposure may lead to humoral immunological stimulation.
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PMID:Immunoglobulin levels in workers exposed to inorganic mercury. 819 Jul 5

Mercury is the major component of dental amalgam restorative material, which typically has 50% pure elemental mercury. It is also used in some skin creams, and in the manufacturing of plastic, drugs and fungicides. The present study was designed to investigate the toxicity of methyl mercury (MeHg+) on isolated rat hepatocytes using several toxicity parameters. The hepatocytes were isolated by a collagenase perfusion technique and were incubated with different concentrations of MeHg+ (0.1-100 ppm) for 2 h. Through the incubation period the viability was determined by Trypan blue exclusion. Reduced glutathione (GSH) content and its enzymes, glutathione peroxidase (GSH-PX) and glutathione reductase (GSH-RX) were measured. Leakage of enzymes such as aspartate transaminase (AST), and alanine transaminase (ALT) were determined. The cell viability was reduced significantly after 1 h incubation when 0.1 and 1 ppm MeHg+ were applied. The decrease in the cell viability was dose- and time-dependent. A depletion of GSH content was observed with 100 ppm MeHg+ after 30 min of incubation. A significant decrease in GSH-RX was observed with 100 ppm during 15 and 30 min of incubation, while 10 ppm of MeHg+ significantly increased ALT leakage after 60 min. However, there was a significant increase in AST leakage with 100 ppm only. The present investigation indicates that the toxic effect of MeHg+ is most likely cytosolic enzyme related.
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PMID:The mechanism of methyl mercury toxicity in isolated rat hepatocytes. 835 70


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