Search results for "GLUTATHIONE"
showing 10 items of 743 documents
Effects of aldicarb and propoxur on cytotoxicity and lipid peroxidation in CHO-K1 cells
2010
Abstract Cytotoxic effects of aldicarb, its sulfone and sulfoxide, and propoxur, lipid peroxidation and antioxidant parameters in Chinese Hamster Ovary (CHO-K1) cells were determined. d , l -buthionine-( S , R )-sulfoximine (BSO) was assayed to determine the role of GSH in the protection against carbamate cytotoxicity. Pre-treatment with 60 μM BSO, induced a significant decrease in the glutathione reductase (GR; 64–141%), the glutathione peroxidase (GPx; 10–30%) and the glutathione S-transferase (GST; 59–93%) activities, and its GSH levels (79–85%), while the oxidized glutathione (GSSG) levels significantly increased (64–78%) respect to experiment non-BSO-pretreated. Carbamates BSO pre-trea…
Increased recovery of brain acetylcholinesterase activity in dichlorvos-intoxicated European eels Anguilla anguilla by bath treatment with N-acetylcy…
2003
Organophosphate (OP) pesticides are widely used as antiparasitic chemicals in finfish aquaculture. However, current antidotes cannot be applied to treat intoxicated fish. We showed in previous studies the importance of glutathione (GSH) metabolism in pesticide resistance of the European eel Anguilla anguilla L. The present work studied the effects of the antioxidant and glutathione pro-drug N-acetyl-l-cysteine (NAC) on the recovery of European eels exposed for 96 h to a sublethal concentration (0.17 mg l^-1; 20% of its 96 h LC50) of the OP pesticide dichlorvos (2,2-dichlorovinyl dimethyl phosphate; DDVP). This insecticide and acaricide decreased muscular GSH content and increased oxidised g…
Effects of four carbamate compounds on antioxidant parameters
2009
Abstract The effect of four carbamates, aldicarb and its metabolites (aldicarb sulfone and aldicarb sulfoxide) and propoxur on glutathione content and the activity of the enzymes involved in the sulfur-redox cycle in the mammalian cellular model CHO-K1 cells after 24-h exposure were determined. Carbamate exposure resulted in a depletion of intracellular reduced glutathione (GSH) content, no change was observed in oxidized glutathione (GSSG) and a decrease in GSH/GSSG ratio was detected. After carbamates exposition a GSH/GSSG decreases in ranged from 12.44% to 21.35% of control was observed. Depletion of GSH levels was accompanied by the induction of glutathione reductase (GR) after 24 h exp…
Cytotoxic effect of As(III) in Caco-2 cells and evaluation of its human intestinal permeability.
2005
Inorganic arsenic has been classified as a carcinogen for humans (Group I). However, its transit across the human intestinal epithelium has not been characterized. Using Caco-2 cells, the thiol-redox balance and apparent permeability coefficients (P(app)) for As(III) in the apical to basolateral (AP-BL) and basolateral to apical (BL-AP) direction were evaluated. After As(III) exposure, GSH-induced synthesis was observed, increasing the GSH/GSSG ratio by elevating the As(III) concentration. The AP-BL permeabilities decreased as the As(III) concentrations increased, indicating the existence of a mediated transport mechanism. The (BL-AP)/(AP-BL) permeability ratios were higher than unity, sugg…
Dinitrosyl-iron triggers apoptosis in Jurkat cells despite overexpression of Bcl-2
2004
Cells expressing the cytokine-inducible NO synthase are known to trigger apoptosis in neighboring cells. Paramagnetic dinitrosyl nonheme iron complexes (DNIC) were found in tumor tissue about 40 years ago; however, the role of these NO(+)-bearing species is not completely understood. In the human Jurkat leukemia cell line, the application of the model complex DNIC-thiosulfate (50-200 microM) induced apoptosis (defined by phosphatidylserine externalization) in a concentration- and time-dependent manner. In Jurkat cells, the pan-caspase inhibitor, zVADfmk (50 microM), and/or stable transfection of antiapoptotic protein, Bcl-2, was unable to afford protection against DNIC-induced apoptosis. Th…
Stimulation of Fe-S cluster insertion into apoFNR by Escherichia coli glutaredoxins 1, 2 and 3 in vitro.
2004
Abstract The oxygen sensor fumarate nitrate reductase regu-lator (FNR) of Escherichia coli contains in the active (anaerobic)state a [4Fe–4S] 2þ cluster which is lost after exposure to O 2 .Inaerobically prepared apoFNR, or in FNR obtained by treatmentof [4Fe–4S] FNR with O 2 in vitro, intramolecular cysteinedisulfides are found, including the cysteine residues which serveas ligands for the Fe–S cluster. It is shown here that thereconstitution of [4Fe–4S] FNR from this form of aerobicapoFNR was preceded by a long lag phase when glutathione wasused as the reducing agent. Addition of E. coli glutaredoxins(Grx) 1, 2 or 3 decreased the lag phase greatly and stimulatedthe reconstitution rate slig…
Priming for JA-dependent defenses using hexanoic acid is an effective mechanism to protect Arabidopsis against B. cinerea
2011
Abstract Soil drench treatments with hexanoic acid can effectively protect Arabidopsis plants against Botrytis cinerea through a mechanism based on a stronger and faster accumulation of JA-dependent defenses. Plants impaired in ethylene, salicylic acid, abscisic acid or glutathion pathways showed intact protection by hexanoic acid upon B. cinerea infection. Accordingly, no significant changes in the SA marker gene PR-1 in either the SA or ABA hormone balance were observed in the infected and treated plants. In contrast, the JA signaling pathway showed dramatic changes after hexanoic acid treatment, mainly when the pathogen was present. The impaired JA mutants, jin1-2 and jar1 , were unable …
Inhibition of γ-glutamyl transpeptidase decreases amino acid uptake in human keratinocytes in culture
1990
Abstract Acivicin inhibits γ-glutamyl transpeptidase activity in human keratinocytes in culture. Treatment of these cells with acivicin produces a decrease in the uptake of L-[U-14C]alanine, 2-amino-[1-14C]-isobutyrate, L[U-14C]leucine and l-aminocyclopentane-l-[14C]carboxylate. D-[U-14C]glucose uptake is not affected by the presence of acivicin. These results support, for the first time in vitro, the hypothesis that the γ-glutarml cycle may be involved in amino acid uptake by human cells.
The use of cultured hepatocytes to investigate the metabolism of drugs and mechanisms of drug hepatotoxicity.
2001
Hepatotoxins can be classified as intrinsic when they exert their effects on all individuals in a dose-dependent manner, and as idiosyncratic when their effects are the consequence of an abnormal metabolism of the drug by susceptible individuals (metabolic idiosyncrasy) or of an immune-mediated injury to hepatocytes (allergic hepatitis). Some xenobiotics are electrophilic, and others are biotransformed by the liver into highly reactive metabolites that are usually more toxic than the parent compound. This activation process is the key to many hepatotoxic phenomena. Mitochondria are a frequent target of hepatotoxic drugs, and the alteration of their function has immediate effects on the ene…
Purification and Characterization of Acidic Glutathione S-Transferases (EC 2.5.1.18) from Rat Kidney
1988
Glutathione S-transferases (EC 2.5.1.18) (GSTs) are present in almost every mammalian tissue and catalyze the conjugation of glutathione (GSH) with different electrophilic substrates (Habig et al. 1974). In contrast to this deactivation function of GSTs, they also appear to be involved in the activation of certain chemicals, and particularly halogenated compounds, in either the liver or extra-hepatic tissues (even the kidney) to nephrotoxic and potentially nephrocarcin-ogenic products (Anders et al. 1987, Dekant et al. 1986, Elfarra and Anders 1984, Igwe 1986). These previous results confirm the necessity of a deeper insight into the GSH conjugation system of the kidney: firstly, because of…