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

Blood sampling site-dependent (the dorsal aorta, the jugular vein, and the retro-orbital sinus) plasma concentrations of acetaminophen and its glucuronide and sulfate conjugates, and acetaminophen-induced hepatotoxic parameters (such as ALT and SDH activity) in serum were evaluated after intraperitoneal administration of acetaminophen, 500 mg/kg body weight, to rats. The plasma concentrations and the resultant AUC0-12 h of acetaminophen, acetaminophen-glucuronide, and acetaminophen-sulfate were significantly higher when blood samples were collected from the retro-orbital sinus than those from the jugular vein. The serum ALT activity at 3 and 24 h after administration of acetaminophen were significantly higher when the blood samples were collected from the retro-orbital sinus than those from the dorsal aorta.
Res Commun Mol Pathol Pharmacol 1998 Sep
PMID:Blood sampling site-dependent plasma concentrations and hepatotoxic parameters in serum after intraperitoneal administration of acetaminophen to rats. 987 85

2-(Allylthio)pyrazine (2-AP), a synthetic organosulfur compound, exhibits hepatoprotective and chemopreventive effects. The effects of 2-AP on aflatoxin B1 (AFB1)-induced hepatotoxicity was studied in rats. 2-AP treatment substantially reduced AFB1-induced toxicity, as evidenced by reduction in the mortality rate of animals as well as decreases in serum alanine aminotransferase and sorbitol dehydrogenase activities. AFB -induced lipid peroxidation was also significantly reduced in rats by 2-AP treatment. Studies were extended to determine whether 2-AP was active in inhibiting cytochrome P450-mediated metabolic activation of AFB1. Covalent binding of AFB1 to calf thymus DNA in the presence of S-9 fraction was inhibited by 2-AP in vitro. Hepatic microsomal pentoxyresorufin-O-depentylase and ethoxyresorufin-O-deethylase activities were also potently inhibited by 2-AP. These results demonstrated that 2-AP was effective in protecting the liver against AFB1-induced toxicity and the mechanism of chemoprotection by 2-AP might involve inhibition of the P450 2B- and 3A2-mediated metabolism of AFB1.
Res Commun Mol Pathol Pharmacol 1998 Oct
PMID:2-(allylthio)pyrazine inhibition of aflatoxin B1-induced hepatotoxicity in rats: inhibition of cytochrome P450 2B- and 3A2-mediated bioactivation. 992 Mar 47

The use of Cyclophosphamide, an anti-cancer and immunosuppressant drug, is accompanied by a number of side effects. Rats injected with a single dose of cyclophosphamide (200 mg kg-1 body weight) showed an increase in the levels of serum glutamate-oxaloacetate transaminase, serum glutamate-pyruvate transaminase, glucose-6-phosphate dehydrogenase and creatine phosphokinase isoenzyme by 53, 24, 55 and 135%, respectively. Also the ability of heart or liver mitochondria to retain accumulated Ca2+ and tetraphenylphosphonium ion was sharply affected in treated rats. Rats injected with the same dose of cyclophosphamide plus cyclosporin A (500 micrograms kg-1 body weight) showed reduction in the levels of those enzymes by about 44, 21, 43 and 57%, respectively compared to cyclophosphamide-treated rats. Cyclosporin A treatment also restored mitochondrial ability to retain accumulated Ca2+ and tetraphenyl phosphonium ions nearly to the level of untreated rats. We suggest that cyclophosphamide induced cardio and hepatotoxicity by increasing heart and liver inner mitochondrial membrane permeability to Ca2+. The protective effect of cyclosporin A against cyclophosphamide-induced damage also support this suggestion.
Comp Biochem Physiol A Mol Integr Physiol 1998 Nov
PMID:In vivo prevention of cyclophosphamide-induced Ca2+ dependent damage of rat heart and liver mitochondria by cyclosporin A. 997 18

A cDNA clone encoding alanine aminotransferase (AlaAT) has isolated from randomly sequenced clones derived from a cDNA library of maturing rice seeds by comparison to previously identified genes. The deduced amino acid sequence was 88% and 91% homologous to those of the enzymes from barley and broomcorn millet (Panicum miliaceum), respectively. Using this cDNA as a probe, we isolated and sequenced the corresponding genomic clone. Comparison of the sequences of the cDNA and the genomic gene revealed that the coding region of the gene was interrupted by 14 introns 66 to 1547 bp long. Northern and western blotting analyses showed that the gene was expressed at high levels in developing seeds. When the 5'-flanking region between -930 and +85 from the site of initiation of transcription was fused to a reporter gene for beta-glucuronidase (GUS) and then introduced into the rice genome, histochemical staining revealed strong GUS activity in the inner endosperm tissue of developing seeds and weak activity in root tips. Similar tissue-specific expression was also detected by in situ hybridization. These results suggest that AlaAT is involved in nitrogen metabolism during the maturation of rice seed.
Plant Mol Biol 1999 Jan
PMID:Molecular characterization of a gene for alanine aminotransferase from rice (Oryza sativa). 1008 Jul 17

Thymoquinone (TQ) is the major active component of the volatile oil of Nigella sativa seeds. The effects of TQ on carbon tetrachloride (CCl4)-induced hepatotoxicity was investigated in male Swiss albino mice. Carbon tetrachloride (20 microliters/Kg, i.p.) injected into mice, induced damage to liver cells and was followed by the increase in serum alanine aminotransferase (ALT) activity after 24 h. Oral administration of TQ in a single dose (100 mg/Kg) resulted in significant (p < 0.001) protection against the hepatotoxic effects of CCl4. TQ was tested as a substrate for mice hepatic DT-diaphorase in the presence of NADH. TQ appears to undergo reduction to dihydrothymoquinone (DHTQ). Reduction rates as a function of protein (liver homogenate) and substrate (TQ) concentrations are reported. An apparent K(m) of 0.1 mM and an apparent Vmax of 74 mumol/min/g liver were measured. TQ and DHTQ inhibited the in vitro non-enzymatic lipid peroxidation in liver homogenate (induced by Fe(3+)-ascorbate) in a dose dependent manner. In this in vitro model DHTQ was more potent in comparison with TQ and butylated hydroxytoluene (BHT). The IC50 for DHTQ, TQ and BHT were found to be 0.34, 0.87 and 0.58 microM respectively. The data suggest that the in vivo protective action of TQ against CCl4-induced hepatotoxicity may be mediated through the combined antioxidant properties of TQ and its metabolite DHTQ.
Biochem Mol Biol Int 1999 Jan
PMID:Thymoquinone protects against carbon tetrachloride hepatotoxicity in mice via an antioxidant mechanism. 1009 55

The effect of various metabolic inhibitors on the rate of oxygen consumption by procyclic culture forms of Trypanosoma congolense utilizing proline as substrate was investigated. Cyanide inhibited the rate of oxygen consumption by 81.0 +/- 6.7%, malonate inhibited the rate by 51.6 +/- 1.6% and Antimycin A by 73.1 +/- 5.9%. A combination of cyanide and malonate inhibited the rate of oxygen consumption by 84.9 +/- 6.7% while a combination of antimycin A and malonate inhibited the rate by 81.6 +/- 7.6%. Rotenone had no effect on the rate of respiration except when the intact cells were first permeabilized by digitonin after which rotenone decreased the rate of respiration by 20-30%. Salicylhydroxamate (SHAM) did not have any effect on the rate of oxygen consumption. Enzymes involved in the catabolism of proline with high activities were: proline dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, fumarase, NADP-linked malic enzyme, alanine aminotransferase and malate dehydrogenase. Activities of 1-pyrroline-5 carboxylate dehydrogenase, glutamate dehydrogenase, aspartate aminotransferase and NAD-linked malic enzyme were detectable but lower. The end products of proline catabolism were alanine and glutamate. Unlike the case in Trypanosoma brucei brucei aspartate was not detected. Possible pathways of proline catabolism in procyclic culture forms of T. congolense and of electron transfer are proposed.
Comp Biochem Physiol B Biochem Mol Biol 1999 May
PMID:Catabolism of proline by procyclic culture forms of Trypanosoma congolense. 1042 13

The aim of this study was to identify apolar aldehydes in liver homogenates from rats with CCl4-induced cirrhosis and, as a corollary, the antioxidant effect of zinc administration. The study was performed in five control rats and in ten cirrhotic rats which were further sub-divided into two groups to receive either a standard diet or one supplemented with zinc. The percentage of hepatic fibrosis, plasma malondialdehyde concentration and alanine aminotransferase activity were measured as well as the following aldehydes: hexanal, octanal, decanal, 2-hexenal, 2-octenal, 2-nonenal, 2,4-heptadienal and 2,4-decadienal. Of the 10 cirrhotic rats, 4 had elevated concentrations of the highly toxic 2,4-dialkenals which coincided with a higher percentage of fibrosis and plasma alanine aminotransferase activity. These aldehydes were not observed in the control group. Zinc administration was associated with a reduction of the hepatic malondialdehyde concentration and an amelioration on the degree of hepatic injury. In conclusion, this study demonstrates the presence of the highly toxic 2,4-dialkenals in hepatic tissue of rats whith CCl4-induced cirrhosis. Results obtained would suggest that these particular aldehydes may be related to the severity of the hepatic injury.
Mol Cell Biochem 1999 Aug
PMID:Hepatic production of apolar aldehydes in rats with carbon tetrachloride-induced cirrhosis. 1049 78

In this work we investigate the possible toxicity of vanadyl sulfate (VOSO4), a compound capable of reducing hyperglycemia, on the following serum enzymes of diabetic young rats: alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LD) and creatine kinase (CK), as well as its effects on serum lipids. We find that at a concentration of 1 mg/mL VOSO4 has no toxic effect on the liver and muscles of diabetics young rats. These findings suggest that VOSO4 may be an alternative to insulin in the near future, due to its low cost, low toxicity and ready availability.
Mol Cell Biochem 1999 Aug
PMID:Effect of oral vanadyl sulfate treatment on serum enzymes and lipids of streptozotocin-diabetic young rats. 1049 91

The effect of pentoxifylline on anti-Fas antibody-induced hepatitis was studied. The administration of anti-Fas antibodies (250 microg/kg, i.v.) to mice elevated plasma alanine aminotransferase (ALT) activity at 3 h. This anti-Fas antibody-induced elevation of ALT was inhibited by treatment with pentoxifylline at the doses of 10 and 100 mg/kg (i.p.). Anti-Fas antibody administration also elevated the CPP32-like protease activity in the liver at 3 h. Although pentoxifylline at 100 mg/kg, i.p., inhibited the anti-Fas antibody-induced elevation of plasma ALT, this treatment did not significantly inhibit the anti-Fas antibody-induced elevation of CPP32-like activity. The present results clearly showed that treatment with pentoxifylline inhibited anti-Fas antibody-induced hepatitis, at least in part, by affecting a reaction downstream of CPP32-like protease activation.
Int J Mol Med 1999 Dec
PMID:Pentoxifylline inhibits anti-Fas antibody-induced hepatitis by affecting downstream of CPP32-like activity in mice. 1056 69

Phenolic antioxidants, such as butylated hydroxyanisole (BHA) and propyl gallate (PG), have demonstrated paradoxical cancer initiating and preventive actions in animals. Studies examining the disposition and biological effects of these agents have used solutions in ethanol-saline, PEG400-saline, corn oil, or DMSO. The aim of this study was to compare the pharmacokinetics of BHA and PG in mice following dosing in either a "control" dosing vehicle (ethanol-saline, 2:3) or a solution of an inclusion complex of each agent with hydroxypropyl-beta-cyclodextrin (HPB) in saline. Results demonstrate that BHA or PG are rapidly absorbed and eliminated in mice following i.p. or p.o. dosing in either dosing vehicle. Pharmacokinetic parameters of BHA estimated in mice correlated with those reported for other species, including humans ("Interspecies Scaling"), suggesting that exposures are proportional to body weight across species. Therefore, rodents are appropriate animal models to study these phenolic antioxidants. The oral absorption of PG was influenced by dosing vehicle in mice, suggesting the need for cautious selection of traditional nonaqueous vehicles (such as DMSO, ethanol, etc.) in the investigation of biological activities of these xenobiotics. Indeed, DMSO elevated plasma alanine aminotransferase (ALT) and alkaline phosphatase (ALP) concentrations following subchronic i.p. administration of various blank vehicles to mice. Such elevations in plasma concentrations of these enzymes are considered biomarkers of hepatotoxicity. The absolute oral bioavailability of PG (administered as an HPB complex) in rats was low (5%) suggesting extensive metabolism or incomplete absorption. The low oral bioavailability of these phenolic antioxidants in rodents suggests that the risk assessment of these antioxidants should include an evaluation of their metabolites as well.
Res Commun Mol Pathol Pharmacol 1999
PMID:Influence of dosing vehicles on the preclinical pharmacokinetics of phenolic antioxidants. 1060 82


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