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)

The authors studied the pharmacotherapeutic efficacy of antioxidants vitamin E, sodium selenite, and their combination in damage to rat liver by CCl4 and the anthelmintic agent chloxyl. Changes of the intensity of peroxidation of biological membrane lipids, the activity of enzymes-markers of hepatocyte cytolysis--alanine aminotransferase and aspartate aminotransferase--in blood serum, and changes in the structure of the liver were studied. Antioxidants and their combination blocked lipid peroxidation, reduced the activity of alanine aminotransferase and aspartate aminotransferase in blood serum considerably, and caused a protective effect on the structure of rat liver in its damage by CCl4 and chloxyl.
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PMID:[Experimental antioxidant therapy in toxic liver damage from CCl4 and chloxyl]. 255 82

Three chlorinated methanes, carbon tetrachloride, chloroform, and methylene chloride, known to cause liver tumors in rodents, were given by oral gavage to adult female rats both 21 h and 4 h before sacrifice. Then hepatic DNA damage, ornithine decarboxylase (ODC), cytochrome P-450, glutathione content, and serum alanine aminotransferase (SGPT) activity assays were performed. Carbon tetrachloride increased rat hepatic ODC activity and decreased cytochrome P-450 content at doses both below and above cytotoxicity (as measured by increased SGPT activity). At 54 and 160 mg/kg, chloroform increased hepatic ODC activity with minimal or no elevation in SGPT activity. At 480 mg/kg chloroform increased hepatic ODC and SGPT activity. A dose of 1,275 mg/kg methylene chloride caused a small, but significant amount of hepatic DNA damage. When these three compounds are compared on either an equimolar or equitoxic (1/5 LD50) basis, their ability to induce hepatic ODC or increase SGPT activity was carbon tetrachloride greater than chloroform greater than methylene chloride. The results of this biochemical study are interpreted with respect to the ability of chemicals to cause hepatic cancer by either genetic or epigenetic mechanisms.
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PMID:Biochemical effects of three carcinogenic chlorinated methanes in rat liver. 256 70

The role of peptide leukotrienes (p-LTs), especially LTC4 and LTD4 in liver disease, was investigated in mice experimental liver injury models. The liver injury was induced by the injection of bacterial lipopolysaccharide (LPS) into Corynebacterium parvum pretreated mice. Carbon tetrachloride (CCl4)-induced liver injury in mice was used as a standard model. In both injury models, extensive liver parenchymal cell damage was observed by the elevation of glutamate transaminase (GOT and GPT) activity and confirmed by significant histopathological changes in the liver. Moreover, significant elevation of LTC4 in the liver was observed in both models 1 and 6 h after the onset of disease. Administration of AA-861, a selective 5-lipoxygenase inhibitor (0.5, 1, and 2 mg/kg) and LY-171883, a p-LT receptor antagonist (50 and 200 mg/kg) suppressed the elevation of serum GOT and GPT levels and histopathological changes in both experimental liver injury models. In addition, when authentic LTC4 or LTD4 was injected into the mouse, clear elevation of serum GOT and GPT and histopathological changes of the liver were observed. These results suggest that p-LTs play a role in the onset of liver diseases in mice.
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PMID:Role of peptide-leukotrienes in liver injury in mice. 257

Rats were injected intraperitoneally with CCl4 (2.5 ml/kg body wt.) and the hepatotoxicity was compared with that of rats receiving the same dose of CCl4 and an intraperitoneal injection of fructose 1,6-bisphosphate (2 g/kg body wt.). A 50-70% decrease in plasma aspartate aminotransferase and alanine aminotransferase activities was observed in the latter treatment, indicating a protective role of the sugar bisphosphate in CCl4 hepatotoxicity. The protection was accompanied by elevated hepatic activities of ornithine decarboxylase at 2, 6 and 24 h, S-adenosylmethionine decarboxylase at 6 h, and spermidine N1-acetyltransferase at 2 h. The increase in the enzymes involved in polyamine metabolism was shown in our previous work [Rao, Young & Mehendale (1989) J. Biochem. Toxicol. 4, 55-63] to correlate with increased polyamine synthesis or interconversion, which was related to the extent of hepatocellular regeneration. The hepatic contents of fructose 1,6-bisphosphate and ATP significantly decreased after CCl4 treatment, and administration of the sugar bisphosphate increased hepatic ATP. Fructose 1,6-bisphosphate, an intermediary metabolite of the glycolytic pathway, may decrease CCl4 toxicity by increasing the ATP in the hepatocytes. The ATP generated is useful for hepatocellular regeneration and tissue repair, events which enable the liver to overcome CCl4 injury.
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PMID:Protective role of fructose 1,6-bisphosphate during CCl4 hepatotoxicity in rats. 259 Jan 62

Water purification generates a variety of chlorinated contaminants, one of which is dichloromaleic acid (DCMA). Exposure to this compound is likely to occur in combination with other drinking water pollutants, some of which are hepatotoxic. This study was designed to examine the interactive effects of carbon tetrachloride (CCl4), a known hepatotoxin, with DCMA on liver and kidney function in the Sprague-Dawley rat. Administration of a single dose of DCMA (200-400 mg/kg, ip) caused modest dose-dependent increases in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and plasma urea nitrogen, as well as a marked depletion of nonprotein sulfhydryls (NPSH) in the liver, but not the kidney, by 24 hr. Pretreatment with inducers (phenobarbital or 3-methylcholanthrene) or an inhibitor (SKF 525A) of cytochrome P-450 activity failed to alter the response observed with DCMA alone. Alterations in 24-hr urine volume, osmolality, and water consumption also were observed. DCMA-mediated changes in plasma urea nitrogen and NPSH were reduced in magnitude with coadministration of CCl4 (1 ml/kg, ip), while anticipated CCl4-induced increases in ALT and AST were reduced with coexposure to DCMA. Renal slice experiments indicated that DCMA-treated rats were less able to accumulate the organic anion p-aminohippurate (PAH), whereas DCMA had no effect on accumulation of the organic cation tetraethylammonium (TEA). The combination of CCl4 and DCMA produced only additive effects on organic ion accumulation. These results suggest hepatic interaction possibly related to the metabolism of CCl4 and DCMA, resulting in renal and hepatic toxicity diminished from that observed with exposure to either agent alone.
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PMID:Effect in the rat of the interaction of dichloromaleic acid and carbon tetrachloride on renal and hepatic function. 261 81

The effect of human placenta hydrolysate (Laennec) on residual liver regeneration after about 70% partial hepatectomy (PH) in normal and CCl4-induced cirrhosis rats was examined. Both intravenous or subcutaneous injections of Laennec increased the regeneration rate of the residual liver after PH in normal rats. Intravenous injection of Laennec inhibited the decrease of liver total protein, and it decreased the level of serum transaminase (GOT, GPT). The regeneration rate of the residual liver after PH in CCl4-induced cirrhosis (CCl4-PH) rats increased by intravenous or subcutaneous injection of Laennec. Laennec also inhibited the increase of serum GOT caused by CCl4-PH. In the pathological examination of the regenerating liver, intravenous injection of Laennec minimized the pathological changes caused by PH or CCl4-PH such as vacuolation and necrosis in the hepatocytes. The enhancement of cytoplasma regeneration in hepatocytes was noticed by intravenous injection of Laennec, but that by subcutaneous Laennec was slight. Intravenous injection of Laennec also minimized the lipid deposition in liver caused by CCl4-PH. Laennec had no effect on the pseudolobule formation caused by CCl4. Thus, the effect of intravenous injection of Laennec on the liver regeneration in PH rats was much more potent than that by the subcutaneous injection.
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PMID:[A comparative study of human placenta hydrolysate (Laennec) by intravenous or subcutaneous injection on liver regeneration after partial hepatectomy in normal and CCl4-induced cirrhosis rats]. 261 8

The action of schizandrin B (Sin B) was observed in freshly isolated hepatocytes damaged by FeSO4/cysteine and CCl4. Two types of free radicals, .OH and .CCl3, generated from FeSO4/cysteine and CCl4, respectively, induced lipid peroxidation in hepatocytes. It was found that the speed of lipid peroxidation (MDA production) and the degree of alteration in hepatocyte morphology were closely related to the type of free radicals. MDA production and membrane protrusion of hepatocytes injuries by FeSO4/cysteine were faster and more severe than those observed with CCl4. Sin B was shown to decrease the production of MDA and the release of GPT and LDH, and to increase hepatocyte viability as well as maintaining the integrity of the hepatocyte membrane surface. These actions of Sin B were stronger than vitamin E at the same concentration. It was observed that no inhibitory effect of phenobarbital, a typical inducer of cytochrome P-450, as Sin B induced liver cytochrome P-450, on MDA production in hepatocytes damaged by FeSO4/cysteine. The results suggest that Sin B possesses antioxidant activity.
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PMID:[Action of schizandrin B, an antioxidant, on lipid peroxidation in primary cultured hepatocytes]. 262 22

The relationship between carbon tetrachloride (CCl4)-induced hepatotoxicity and hepatic glutathione (GSH) content was investigated in fed and fasted rats. The elevation of serum glutamic-pyruvic transaminase (GTP) activity by CCl4 treatment was enhanced by fasting. Although the hepatic GSH content fo 12-hour-fasted rats was higher than that of fed rats determined at 6 p.m., the serum GPT activity of the former was higher than that of the latter. Starvation had no effect on the activities of hepatic glutathione peroxidase (GSH-Px) and glutathione reductase (GR). The results suggest that the potentiation of hepatic injury by CCl4 cannot be related to hepatic GSH content.
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PMID:Relationship between hepatic glutathione content and carbon tetrachloride-induced hepatotoxicity in vivo. 271 15

The pathogenetic mechanisms of hepatotoxicity of an anthelminthic drug chloxyl as compared with the mechanisms of CCl4 hepatotoxicity were studied on the basis of the change of the liver content of the primary (conjugated dienes) and secondary (malondialdehyde) products of lipid peroxidation. the activity of alanine aminotransferase and aspartate aminotransferase in the blood serum of rats and on the basis of the change of the liver structure. The pathogenetic mechanisms of chloxyl hepatotoxicity are close to those of CCl4 and consist in the activation of membrane lipid peroxidation, that is, an increase of the liver contents of the primary and secondary products of lipid peroxidation, an impairment of permeability of membranes of hepatocytes and their destruction with the release in the blood of cytoplasmic enzymes of alanine aminotransferase and aspartate aminotransferase.
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PMID:[Pathogenetic mechanisms of liver damage by the anthelmintic preparation chloxyl]. 274 47

Aqueous extracts of the aerial parts of Melothria maderasptana and the leaves of Osbeckia octandra have been compared with (+)-3-cyanidanol with regard to their abilities to alleviate carbon tetrachloride (CCl4)-induced liver dysfunction in albino rats by comparing the abilities of these drugs to protect the liver against CCl4-mediated alterations in the liver histopathology and serum levels of aspartate aminotransferase (GOT), alkaline amino-transferase (GPT), and alkaline phosphatase. In both pretreatment and post-treatment (administration of drugs before or after CCl4 treatment) experiments, the most marked rate of recovery of the liver was exhibited by the group of rats treated with Melothria maderaspatana extract. Although the protection offered by (+)-3-cyanidanol and Osbeckia octandra appears to be comparable in post-treatment, Osbeckia was significantly more effective in pre-treatment. From the overall results obtained it appears that the aqueous extracts of Melothria maderaspatana and Osbeckia octandra are both as potent or in some instances (in pretreatment experiments) more potent than (+)-3-cyanidanol. Of the two plants tested under the present experimental conditions used, Melothria maderaspatana appears to be marginally more effective than Osbeckia octandra in protecting the liver against CCl4-induced alterations.
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PMID:An evaluation of the potency of Osbeckia octandra and Melothria maderaspantana as antihepatotoxic agents. 274 29


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