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:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Male Sprague-Dawley rats, who had received 50 micrograms/ml of arsenic (as sodium arsenate) in drinking water for 320 days, showed high urinary excretion of this element. Arsenic was accumulated in tissues, mostly in the kidney and in the liver. In the kidney were evident slight focal alterations in tubules and glameruli; some of the tubules contained casts of amorphous hyaline material. The hepatocytes close to the centrolobular veins were swollen and showed ultrastructural alterations. The seric GOT, GPT and LDH activities were normal, while the alkaline phosphatase alto have been found in the brain, sciatic nerve, lung, heart and arteries. No significant changes of systolic and diastolic blood pressure levels were observed. Similarly, cardiac inotropism and chronotropism were unchanged. The electrocardiogram, also, was normal. The cardiovascular reactivity to noradrenaline, acetylcholine, histamine, serotonin, bradykinin and angiotensin II was unchanged. However, the vascular reactivity to the beta-stimulation was increased, while it was decreased to the angiotensin I. On the whole, our results suggest that chronic arsenic exposure produces focal alterations in the kidney and characteristic modifications in the hepatic structure and in the cardiovascular reactivity.
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PMID:[Chronic exposure to arsenic in rats: morphological and functional findings]. 676 36

The effects of meso 2, 3-dimercaptosuccinic acid (DMSA), sodium 2, 3-dimercaptopropane 1-sulfonate (DMPS) and S-adenosyl L-methionine (SAM) on the enzymatic activities of mice were studied. The mice were given intraperitoneal (i.p.) injections of these chelating agents (1 mmol/kg) and 3 h later the activity of delta-aminolevulinic acid dehydratase (ALAD) in the blood, and aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltranspeptidase (gamma-GT), alkaline phosphatase (ALP) in the liver and kidney were determined. The activity of blood ALAD was significantly increased by the administration of DMSA and SAM while DMPS had only a moderate effect. The activities of other hepatic enzymes changed little when the mice were treated with these chelating agents, except for a significant reduction in hepatic ALP activity following DMPS administration. Arsenic (III) administration markedly increased the activities of ALT and ALP in the liver and kidneys. The changes in the enzymatic activities by treatment with arsenic were prevented by injection of DMSA, DMPS and SAM, DMSA being the most effective. These results indicate that DMSA, DMPS and SAM were not toxic to the liver or kidneys of mice and that treatment with DMSA is more effective than DMPS or SAM in protecting mice from acute hepatic or renal toxicity caused by arsenic.
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PMID:Effects of some thiol chelators on enzymatic activities in blood, liver and kidneys of acute arsenic (III) exposed mice. 955 1

Arsenic is an environmental toxicant. Active extrusion via the ArsAB pump is a mechanism for arsenic detoxication in bacteria. However, how arsenic is effluxed from mammalian cells is not completely known. Our recent work shows that acquired arsenic resistance is associated with overexpression of P-glycoprotein and can be reversed by PSC833, an inhibitor for P-glycoprotein. This study utilized the mdr1a/1b(-/-) mice, which lack mdr1-type P-glycoproteins, to examine whether these mice are sensitive to arsenic toxicity and have higher arsenic accumulation in their tissues. The mdr1a/1b(-/-) and wild-type FVB mice were given arsenic as sodium arsenite (12-19 mg/kg, sc) and toxicity was examined 24 h later. The mdr1a/1b(-/-) mice were more sensitive than wild-type mice to arsenite-induced lethality, with LD(50) of 14.5 and 17 mg/kg, respectively. Histologically, arsenite produced more frequent and more severe lesions in the liver and kidney of the mdr1a/1b(-/-) mice than in wild-type mice. Serum alanine aminotransferase activity and blood urea nitrogen levels, indicative of hepatic and renal damage respectively, were increased 4 to 6-fold in the mdr1a/1b(-/-) mice as compared with 1-2-fold increases in wild-type mice. The mdr1a/1b(-/-) mice accumulated more arsenic in the liver (15.3 vs. 5.2 microg/g), kidney (7.23 vs. 3.22 microg/g), small intestine (3.98 vs. 1.57 microg/g) and brain (0.45 vs. 0.17 microg/g), as compared with wild-type mice 24 h after sodium arsenite (14 mg/kg, s.c.) administration. In summary, this study demonstrated that the mdr1a/1b(-/-) mice were more sensitive to acute arsenic toxicity and accumulated more arsenic than wild-type mice, suggesting that P-glycoproteins are involved, at least in part, in arsenic efflux in mammalians.
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PMID:Multidrug-resistance mdr1a/1b double knockout mice are more sensitive than wild type mice to acute arsenic toxicity, with higher arsenic accumulation in tissues. 1175 83

Short term exposure of arsenic produces carbohydrate depletion and hypoglycemia. Dietary deficiency of methionine causes impaired biotransformation of arsenic which has been attributed to the pathogenesis of different diseases induced by arsenic. Accordingly, the effects of methionine supplementation on the altered glucose homeostasis induced by arsenic were studied. Arsenic (as sodium arsenite) treatment (i.p) of male Wistar rats (weighing 80-100 g) at a dose of 5.55 mg kg(-1) body weight (equivalent to 35% LD50) per day for a period of 21 days caused a significant diminution in blood glucose level and fall in liver glycogen and pyruvic acid contents. The free amino acid nitrogen content of liver was elevated while that of kidney was decreased after arsenic treatment. Transaminase activities in liver and kidney were not significantly altered except that glutamate-pyruvate transaminase activity of kidney decreased significantly after arsenic treatment. Methionine supplementation reversed the above changes except decreased liver glycogen due to arsenic treatment. It may be suggested that hypoglycemia with associated decreased glycolytic activity induced by arsenic treatment at the present dose and duration can be partially counteracted by dietary methionine supplementation.
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PMID:Protective effect of methionine supplementation on arsenic-induced alteration of glucose homeostasis. 1504 19

N-acetylcysteine (NAC), a synthetic aminothiol, possesses antioxidative and cytoprotective properties. The present study evaluates the effect of NAC supplementation on arsenic-induced depletion in vivo of carbohydrates. Arsenic (as sodium arsenite) treatment (i.p.) of male Wistar rats (120-140 g b.w.) at a dose of 5.55 mg/kg body weight (35% of LD50) per day for a period of 30 days produced a significant decrease in blood glucose level (hypoglycemia) and a fall in liver glycogen and pyruvic acid contents. The free amino acid nitrogen content of liver increased while that of kidney decreased after arsenic treatment. Arsenic also enhanced the liver lactate dehydrogenase activity whereas glucose 6-phosphatase activity in both liver and kidney decreased significantly following arsenic treatment. Transaminase activities in liver and kidney were not significantly altered except the glutamate-pyruvate transaminase activity that was reduced in kidney after arsenic treatment. Oral administration of NAC (163.2 mg/kg/day) for last 7 days of treatment prevented the arsenic-induced hypoglycemia and glycogenolytic effects to an appreciable extent. There was also recovery of liver pyruvic acid as well as liver and kidney free amino acid nitrogen content after NAC supplementation. Arsenic-induced alteration of glucose 6-phosphatase activity in both liver and kidney was also counteracted by NAC. It is suggested that carbohydrate depletion in vivo due to exposure to arsenic can be counteracted by NAC supplementation.
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PMID:Protective effect of N-acetylcysteine against arsenic-induced depletion in vivo of carbohydrate. 1519 77

Subchronic exposure to arsenic is associated with alteration of glucose homeostasis. Arsenic treatment (as sodium arsenite) of male Wistar rats (weighing 130-150 g) at a dose of 5.55 mg kg(-1) body weight (equivalent to 35% of LD(50)) (i.p.) per day for a period of 30 days produced hypoglycemia, with associated increased urinary excretion of glucose and depletion of liver glycogen and pyruvic acid contents. Mobilization of free amino acids from kidney to liver was facilitated by arsenic treatment. Arsenic exposure significantly decreased the glutamate-pyruvate transaminase activity in kidney. Glucose 6-phosphatase activity in liver tissue was also significantly decreased after arsenic treatment. In addition to these, liver lactate dehydrogenase activity was elevated due to arsenic treatment. Melatonin supplementation (i.p.) at a dose of 10 mg kg(-1) day(-1) for last five days prior to sacrifice reversed most of the above changes caused by arsenic. Melatonin, being a potent free radical scavenger may reduce arsenic-induced free radical production, and thereby, eliminating its toxic effects. So, arsenic-induced hypoglycemia, with associated glycogenolytic as well as glycolytic activities of liver can be partially counteracted by melatonin supplementation. Accordingly, it may be suggested that melatonin can serve as a prospective protective agent against arsenic-induced metabolic toxicity.
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PMID:Prospective protective role of melatonin against arsenic-induced metabolic toxicity in Wistar rats. 1566 30

This experiment was conducted to investigate the effect of dietary arsenic (As) levels on growth performance, serum biochemistry, and the retention of iron, copper, and zinc in tissues of growing and finishing pigs. Ninety-six crossbred pigs were randomly allotted to four dietary treatments. The corn-soybean basal diets were supplemented with 0, 10, 20, and 30 mg As/kg. Arsenic trioxide was used as the arsenic source. The feeding experiment lasted for 78 d. The results showed that the high arsenic diet decreased average daily gain (ADG) (p<0.05) and increased feed gain ratio (F/G) (p<0.05). Arsenic intake significantly increased (p<0.05) serum gamma-gultamyltransferase (GGT), glutamic-pyruvic transaminase (GPT), and alkaline phosphatase (ALP) activities, and decreased (p<0.05) total protein, urea nitrogen, creatinine, and triglycerides. Glutamic-oxalacetic transaminase (GOT) activity, albumin, and cholesterol were not affected (p>0.05). Arsenic feeding elevated (p<0.05) liver and kidney copper concentration, but reduced (p<0.05) copper concentration in heart, bile, and lymphaden of intestine mesentery. There were increases in iron levels in liver, bile, spleen, thymus, and pancreas in pigs fed the high As diets (p<0.05), but iron contents in kidney, heart, and serum were decreased by the arsenic treatment (p<0.05). Zinc concentrations were increased (p<0.05) in liver, kidney, and thymus of pigs with arsenic treatment, but decreased (p<0.05) in bile and lymphaden of intestine mesentery. This study suggested that high dietary As levels could alter serum biochemical parameters and the retention of copper, iron, and zinc in the viscera of growing and finishing pigs.
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PMID:Effects of dietary arsenic levels on serum parameters and trace mineral retentions in growing and finishing pigs. 1719 18

Co-administration of iron in combination with monoisoamyl dimercaptosuccinic acid (MiADMSA) against chronic arsenic poisoning in mice was studied. Mice preexposed to arsenic (25 ppm in drinking water for 6 months) mice were treated with MiADMSA (50 mg/kg, intraperitoneally) either alone or in combination with iron (75 or 150 mg/kg, orally) once daily for 5 days. Arsenic exposure led to a significant depletion of blood delta-aminolevulinic acid dehydratase (ALAD) activity, hematocrit, and white blood cell (WBC) counts accompanied by small decline in blood hemoglobin level. Hepatic reduced glutathione (GSH) level, catalase and superoxide dismutase (SOD) activities showed a significant decrease while, oxidized glutathione (GSSG) and thiobarbituric acid-reactive substances (TBARS) levels increased on arsenic exposure, indicating arsenic-induced hepatic oxidative stress. Liver aspartate and alanine transaminases (AST and ALT) activities also decreased significantly on arsenic exposure. Kidney GSH, GSSG, catalase level and SOD activities remained unchanged, while, TBARS level increased significantly following arsenic exposure. Brain GSH, glutathione peroxidase (GPx), and SOD activities decreased, accompanied by a significant elevation of TBARS level after chronic arsenic exposure. Treatment with MiADMSA was marginally effective in reducing ALAD activity, while administration of iron was ineffective when given alone. Iron when co-administered with MiADMSA restored blood ALAD activity. Administration of iron alone had no beneficial effects on hepatic oxidative stress, while in combination with MiADMSA it produced significant decline in hepatic TBARS level compared to the individual effect of MiADMSA. Renal biochemical variables were insensitive to any of the treatments. Combined administration of iron with MiADMSA also had no additional beneficial effect over the individual protective effect of MiADMSA on brain oxidative stress. Interestingly, combined administration of iron with MiADMSA provided more pronounced depletion of blood arsenic, while no additional beneficial effects on tissue arsenic level over the individual effect of MiADMSA were noted. The results lead us to conclude that iron supplementation during chelation has some beneficial effects particularly on heme synthesis pathway and blood arsenic concentration.
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PMID:Combined administration of iron and monoisoamyl-DMSA in the treatment of chronic arsenic intoxication in mice. 1745 51

Arsenic is a potent environmental toxin. Present study has been designed to evaluate the protective role of taurine (2-aminoethanesulfonic acid) against arsenic induced cytotoxicity in murine hepatocytes. Sodium arsenite (NaAsO(2)) was chosen as the source of arsenic. Incubation of hepatocytes with the toxin (1 mM) for 2 h reduced the cell viability as well as intra-cellular antioxidant power. Increased activities of alanine transaminase (ALT) and alkaline phosphatase (ALP) due to toxin exposure confirmed membrane damage. Toxin treatment caused reduction in the activities of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx). In addition, the same treatment reduced the level of glutathione (GSH), elevated the level of oxidized glutathione (GSSG) and increased the extent of lipid peroxidation. Incubation of hepatocytes with taurine, both prior to and in combination with NaAsO(2), attenuated the extent of lipid peroxidation and enhanced the activities of enzymatic as well as non enzymatic antioxidants. Besides, taurine administration normalized the arsenic-induced enhanced levels of the marker enzymes ALT and ALP in hepatocytes. The cytoprotective activity of taurine against arsenic poisoning was found to be comparable to that of a known antioxidant, vitamin C. Combining all, the results suggest that taurine protects mouse hepatocytes against arsenic induced cytotoxicity.
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PMID:Taurine, a conditionally essential amino acid, ameliorates arsenic-induced cytotoxicity in murine hepatocytes. 1762 16

Millions of people are at risk of groundwater arsenic contamination, but supply of arsenic-free drinking water is grossly inadequate. The present study was intended to examine if a potentized homeopathic remedy reportedly showing ameliorating potentials in people inhabiting high-risk arsenic-contaminated areas but drinking arsenic-free water, can also ameliorate arsenic toxicity in subjects living in high-risk arsenic-contaminated areas, and drinking arsenic-contaminated water. This pilot study was conducted on 20 males and 19 females of village Dasdiya (arsenic contaminated) who initially agreed to act as volunteers; but as many as 14, mostly placebo-fed subjects, later dropped out. 18 volunteers, 14 males and 4 females, from a distant village, Padumbasan (arsenic-free), served as negative controls. In a double blind placebo-controlled study, a potentized remedy of homeopathic Arsenicum Album-30 and its placebo (Succussed Alcohol-30) were given randomly to volunteers. Arsenic contents in urine and blood and several widely accepted toxicity biomarkers and pathological parameters in blood were analyzed before and after 2 months of administration of either verum or placebo. Elevated levels of ESR, creatinine and eosinophils and increased activities of AST, ALT, LPO and GGT were recorded in arsenic exposed subjects. Decreased levels of hemoglobin, PCV, neutrophil percentages, and GSH content and low G-6-PD activity were also observed in the arsenic exposed people. The administration of "verum" appeared to make positive modulations of these parameters, suggestive of its ameliorative potentials. Most of the subjects reported better appetite and improvement in general health, thereby indicating possibility of its use in remote arsenic-contaminated areas as an interim health support measure to a large population at risk.
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PMID:Homeopathic remedy for arsenic toxicity?: Evidence-based findings from a randomized placebo-controlled double blind human trial. 1762 42


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