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Glutamic Acid Uptake Inhibition Assay in Cultured Hep G2 Cells as an Alternative Method for Evaluating Potential In Vivo Eye Irritation. Altern Lab Anim 2020. [DOI: 10.1177/026119298901600405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glutamic acid (GA) content was measured in cultured Hep G2 cells, after treatment of the cells with test compounds. The results with 37 chemicals were compared with their respective rabbit eye irritation data, of which 17 were determined according to the OECD test, and the other 20 in range-finding studies. The chemicals were mainly organic solvents (alcohols, esters, amines, acids and others). The xenobiotics were applied to the cells for 4 hours at 5 different concentrations. The cells were then incubated for 15 minutes with tritiated GA. GA uptake inhibition was measured by liquid scintillation counting, and the results were expressed as the GI50 value, which is the concentration of test compound required to induce a 50% reduction in GA uptake. A linear correlation coefficient r = 0.66 was found between the log GI50 and the mean corneal opacity scores. This value is comparable to that obtained in total protein and uridine uptake inhibition studies. However, r = 0.81 was found when the log GI50 was compared with range-finding scores, indicating that a closer relationship exists between cytotoxicity and the latter.
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The Influence of Glutathione on the Cytotoxicity of Metals in Rat Hepatoma-derived Fa32 Cells. Altern Lab Anim 2020. [DOI: 10.1177/026119299602400314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The cytotoxicities of mercury, cadmium, nickel, cobalt, zinc and copper were investigated in rat hepatoma-derived Fa32 cells by using the neutral red uptake inhibition assay with three treatment regimens (2 hours, 24 hours and 1 week). Nickel and cobalt were almost non-toxic after 2 hours. Good correlations were observed between the 24-hour and the 1-week cytotoxicities, and cytotoxicity in human hepatoma-derived Hep G2 cells. L-buthionine-S,R-sulphoximine reduced the glutathione content to 5% after 24 hours. The cytotoxicity of the metals increased (3–12 times) in glutathione-depleted cells. A good agreement was demonstrated by HPLC between the glutathione S-transferase (GST) subunit composition in Fa32 cells and in rat liver, except that subunit 7 is also a major subunit in the hepatoma cell line. No evidence was obtained for an interaction of the GSTs in the glutathione-modulated cytotoxicity of the investigated metals.
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Poster session 1Cell growth, differentiation and stem cells - Heart72Understanding the metabolism of cardiac progenitor cells: a first step towards controlling their proliferation and differentiation?73Expression of pw1/peg3 identifies a new cardiac adult stem cell population involved in post-myocardial infarction remodeling74Long-term stimulation of iPS-derived cardiomyocytes using optogenetic techniques to promote phenotypic changes in E-C coupling75Benefits of electrical stimulation on differentiation and maturation of cardiomyocytes from human induced pluripotent stem cells76Constitutive beta-adrenoceptor-mediated cAMP production controls spontaneous automaticity of human induced pluripotent stem cell-derived cardiomyocytes77Formation and stability of T-tubules in cardiomyocytes78Identification of miRNAs promoting human cardiomyocyte proliferation by regulating Hippo pathway79A direct comparison of foetal to adult epicardial cell activation reveals distinct differences relevant for the post-injury response80Role of neuropilins in zebrafish heart regeneration81Highly efficient immunomagnetic purification of cardiomyocytes derived from human pluripotent stem cells82Cardiac progenitor cells posses a molecular circadian clock and display large 24-hour oscillations in proliferation and stress tolerance83Influence of sirolimus and everolimus on bone marrow-derived mesenchymal stem cell biology84Endoglin is important for epicardial behaviour following cardiac injuryCell death and apoptosis - Heart87Ultrastructural alterations reflecting Ca2+ handling and cell-to-cell coupling disorders precede occurrence of severe arrhythmias in intact animal heart88Urocortin-1 promotes cardioprotection through ERK1/2 and EPAC pathways: role in apoptosis and necrosis89Expression p38 MAPK and Cas-3 in myocardium LV of rats with experimental heart failure at melatonin and enalapril introductionTranscriptional control and RNA species - Heart92Accumulation of beta-amyloid 1-40 in HF patients: the role of lncRNA BACE1-AS93Role of miR-182 in zebrafish and mouse models of Holt-Oram syndrome94Mir-27 distinctly regulates muscle-enriched transcription factors and growth factors in cardiac and skeletal muscle cells95AF risk factors impair PITX2 expression leading to Wnt-microRNA-ion channel remodelingCytokines and cellular inflammation - Heart98Post-infarct survival depends on the interplay of monocytes, neutrophils and interferon gamma in a mouse model of myocardial Infarction99Inflammatory cd11b/c cells play a protective role in compensated cardiac hypertrophy by promoting an orai3-related pro-survival signal100Anti-inflammatory effects of endothelin receptor blockade in the atrial tissue of spontaneously hypertensive rats101Mesenchymal stromal cells reduce NLRP3 inflammasome activity in Coxsackievirus B3-induced myocarditis102Mesenchymal stromal cells modulate monocytes trafficking in Coxsackievirus B3-induced myocarditis103The impact of regulatory T lymphocytes on long-term mortality in patients with chronic heart failure104Temporal dynamics of dendritic cells after ST-elevation myocardial infarction relate with improvement of myocardial functionGrowth factors and neurohormones - Heart107Preconditioning of hypertrophied heart: miR-1 and IGF-1 crosstalk108Modulation of catecholamine secretion from human adrenal chromaffin cells by manipulation of G protein-coupled receptor kinase-2 activity109Evaluation of cyclic adenosin-3,5- monophosphate and neurohormones in patients with chronic heart failureNitric oxide and reactive oxygen species - Heart112Hydrogen sulfide donor inhibits oxidative and nitrosative stress, cardiohemodynamics disturbances and restores cNOS coupling in old rats113Role and mechanisms of action of aldehydes produced by monoamine oxidase A in cardiomyocyte death and heart failure114Exercise training has contrasting effects in myocardial infarction and pressure-overload due to different endothelial nitric oxide synthase regulation115S-Nitroso Human Serum Albumin dose-dependently leads to vasodilation and alters reactive hyperaemia in coronary arteries of an isolated mouse heart model116Modulating endothelial nitric oxide synthase with folic acid attenuates doxorubicin-induced cardiomyopathy119Effects of long-term very high intensity exercise on aortic structure and function in an animal model120Electron paramagnetic resonance spectroscopy quantification of nitrosylated hemoglobin (HbNO) as an index of vascular nitric oxide bioavailability in vivo121Deletion of repressor activator protein 1 impairs acetylcholine-induced relaxation due to production of reactive oxygen speciesExtracellular matrix and fibrosis - Heart124MicroRNA-19b is associated with myocardial collagen cross-linking in patients with severe aortic stenosis. Potential usefulness as a circulating biomarker125A new ex vivo model to study cardiac fibrosis126Heterogeneity of fibrosis and fibroblast differentiation in the left ventricle after myocardial infarction127Effect of carbohydrate metabolism degree compensation to the level of galectin-3 changes in hypertensive patients with chronic heart failure and type 2 diabetes mellitus128Statin paradox in association with calcification of bicuspid aortic valve interstitial cells129Cardiac function remains impaired despite reversible cardiac fibrosis after healed experimental viral myocarditisIon channels, ion exchangers and cellular electrophysiology - Heart132Identifying a novel role for PMCA1 (Atp2b1) in heart rhythm instability133Mutations of the caveolin-3 gene as a predisposing factor for cardiac arrhythmias134The human sinoatrial node action potential: time for a computational model135iPSC-derived cardiomyocytes as a model to dissect ion current alterations of genetic atrial fibrillation136Postextrasystolic potentiation in healthy and diseased hearts: effects of the site of origin and coupling interval of the preceding extrasystole137Absence of Nav1.8-based (late) sodium current in rabbit cardiomyocytes and human iPSC-CMs138hiPSC-derived cardiomyocytes from Brugada Syndrome patients without identified mutations do not exhibit cellular electrophysiological abnormalitiesMicrocirculation141Atherogenic indices, collagen type IV turnover and the development of microvascular complications- study in diabetics with arterial hypertension142Changes in the microvasculature and blood viscosity in women with rheumatoid arthritis, hypercholesterolemia and hypertensionAtherosclerosis145Shear stress regulates endothelial autophagy: consequences on endothelial senescence and atherogenesis146Obstructive sleep apnea causes aortic remodeling in a chronic murine model147Aortic perivascular adipose tissue displays an aged phenotype in early and late atherosclerosis in ApoE-/- mice148A systematic evaluation of the cellular innate immune response during the process of human atherosclerosis149Inhibition of Coagulation factor Xa increases plaque stability and attenuates the onset and progression of atherosclerotic plaque in apolipoprotein e-deficient mice150Regulatory CD4+ T cells from patients with atherosclerosis display pro-inflammatory skewing and enhanced suppression function151Hypoxia-inducible factor (HIF)-1alpha regulates macrophage energy metabolism by mediating miRNAs152Extracellular S100A4 is a key player of smooth muscle cell phenotypic transition: implications in atherosclerosis153Microparticles of healthy origins improve atherosclerosis-associated endothelial progenitor cell dysfunction via microRNA transfer154Arterial remodeling and metabolism impairment in early atherosclerosis155Role of pannexin1 in atherosclerotic plaque formationCalcium fluxes and excitation-contraction coupling158Amphiphysin II induces tubule formation in cardiac cells159Interleukin 1 beta regulation of connexin 43 in cardiac fibroblasts and the effects of adult cardiac myocyte:fibroblast co-culture on myocyte contraction160T-tubular electrical defects contribute to blunted beta-adrenergic response in heart failure161Beat-to-beat variability of intracellular Ca2+ dynamics of Purkinje cells in the infarct border zone of the mouse heart revealed by rapid-scanning confocal microscopy162The efficacy of late sodium current blockers in hypertrophic cardiomyopathy is dependent on genotype: a study on transgenic mouse models with different mutations163Synthesis of cADPR and NAADP by intracellular CD38 in heart: role in inotropic and arrhythmogenic effects of beta-adrenoceptor signalingContractile apparatus166Towards an engineered heart tissue model of HCM using hiPSC expressing the ACTC E99K mutation167Diastolic mechanical load delays structural and functional deterioration of ultrathin adult heart slices in culture168Structural investigation of the cardiac troponin complex by molecular dynamics169Exercise training restores myocardial and oxidative skeletal muscle function from myocardial infarction heart failure ratsOxygen sensing, ischaemia and reperfusion172A novel antibody specific to full-length stromal derived factor-1 alpha reveals that remote conditioning induces its cleavage by endothelial dipeptidyl peptidase 4173Attenuation of myocardial and vascular arginase activity by vagal nerve stimulation via a mechanism involving alpha-7 nicotinic receptor during cardiac ischemia and reperfusion174Novel nanoparticle-mediated medicine for myocardial ischemia-reperfusion injury simultaneously targeting mitochondrial injury and myocardial inflammation175Acetylcholine plays a key role in myocardial ischaemic preconditioning via recruitment of intrinsic cardiac ganglia176The role of nitric oxide and VEGFR-2 signaling in post ischemic revascularization and muscle recovery in aged hypercholesterolemic mice177Efficacy of ischemic preconditioning to protect the human myocardium: the role of clinical conditions and treatmentsCardiomyopathies and fibrosis180Plakophilin-2 haploinsufficiency leads to impaired canonical Wnt signaling in ARVC patient181Improved technique for customized, easier, safer and more reliable transverse aortic arch banding and debanding in mice as a model of pressure overload hypertrophy182Late sodium current inhibitors for the treatment of inducible obstruction and diastolic dysfunction in hypertrophic cardiomyopathy: a study on human myocardium183Angiotensin II receptor antagonist fimasartan has protective role of left ventricular fibrosis and remodeling in the rat ischemic heart184Role of High-Mobility Group Box 1 (HMGB1) redox state on cardiac fibroblasts activities and heart function after myocardial infarction185Atrial remodeling in hypertrophic cardiomyopathy: insights from mouse models carrying different mutations in cTnT186Electrophysiological abnormalities in ventricular cardiomyocytes from a Maine Coon cat with hypertrophic cardiomyopathy: effects of ranolazine187ZBTB17 is a novel cardiomyopathy candidate gene and regulates autophagy in the heart188Inhibition of SRSF4 in cardiomyocytes induces left ventricular hypertrophy189Molecular characterization of a novel cardiomyopathy related desmin frame shift mutation190Autonomic characterisation of electro-mechanical remodeling in an in-vitro leporine model of heart failure191Modulation of Ca2+-regulatory function by three novel mutations in TNNI3 associated with severe infant restrictive cardiomyopathyAging194The aging impact on cardiac mesenchymal like stromal cells (S+P+)195Reversal of premature aging markers after bariatric surgery196Sex-associated differences in vascular remodeling during aging: role of renin-angiotensin system197Role of the receptor for advanced glycation end-products (RAGE) in age dependent left ventricle dysfunctionsGenetics and epigenetics200hsa-miR-21-5p as a key factor in aortic remodeling during aneurysm formation201Co-inheritance of mutations associated with arrhythmogenic and hypertrophic cardiomyopathy in two Italian families202Lamin a/c hot spot codon 190: form various amino acid substitutions to clinical effects203Treatment with aspirin and atorvastatin attenuate cardiac injury induced by rat chest irradiation: Implication of myocardial miR-1, miR-21, connexin-43 and PKCGenomics, proteomics, metabolomics, lipidomics and glycomics206Differential phosphorylation of desmin at serines 27 and 31 drives the accumulation of preamyloid oligomers in heart failure207Potential role of kinase Akt2 in the reduced recovery of type 2 diabetic hearts subjected to ischemia / reperfusion injury208A proteomics comparison of extracellular matrix remodelling in porcine coronary arteries upon stent implantationMetabolism, diabetes mellitus and obesity211Targeting grk2 as therapeutic strategy for cancer associated to diabetes212Effects of salbutamol on large arterial stiffness in patients with metabolic syndrome213Circulating microRNA-1 and microRNA-133a: potential biomarkers of myocardial steatosis in type 2 diabetes mellitus214Anti-inflammatory nutrigenomic effects of hydroxytyrosol in human adipocytes - protective mechanisms of mediterranean diets in obesity-related inflammation215Alterations in the metal content of different cardiac regions within a rat model of diabetic cardiomyopathyTissue engineering218A novel conductive patch for application in cardiac tissue engineering219Establishment of a simplified and improved workflow from neonatal heart dissociation to cardiomyocyte purification and characterization220Effects of flexible substrate on cardiomyocytes cell culture221Mechanical stretching on cardiac adipose progenitors upregulates sarcomere-related genes. Cardiovasc Res 2016. [DOI: 10.1093/cvr/cvw135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Comparison of the cytotoxicity of the MEIC reference chemicals measured in protein free and in complete culture medium. Toxicol In Vitro 2005; 19:859-64. [PMID: 16054330 DOI: 10.1016/j.tiv.2005.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Accepted: 06/17/2005] [Indexed: 11/19/2022]
Abstract
In order to investigate if a protein free cytotoxicity assay could improve the prediction of human acute toxicity, the cytotoxicity of 40 MEIC reference chemicals was measured by the neutral red uptake inhibition after 24h in protein free culture medium on rat hepatoma-derived Fa32 cells. The results were compared with the corresponding values obtained in complete culture medium, including 10% fetal calf serum. Potassium cyanide, arsenic trioxide, mercuric chloride, hexachlorophene and pentachlorophenol were much more cytotoxic in PF medium, as was the case to a lower extent for 16 other chemicals. The cytotoxicity of 8 chemicals was only changed to a limited extent when tested in PF medium, suggesting that serum proteins do not strongly interact with their cytotoxicity. Eleven other chemicals were less cytotoxic in PF medium, maybe because of too poor physiological conditions. Although a large number of differences in cytotoxicity were observed in function of the medium used for the assay, a good correlation was observed between both series of data (r(2)=0.946). The correlation between the cytotoxicity in PF medium and the human acute toxicity is lower (r(2)=0.647) than that in complete medium (r(2)=0.746). The results show that further research is necessary in order to improve the in vitro/in vivo correlations by introducing protein-dependent considerations.
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The prediction of human acute systemic toxicity by the EDIT/MEIC in vitro test battery: the importance of protein binding and of partitioning into lipids. Altern Lab Anim 2005; 31:245-56. [PMID: 15612867 DOI: 10.1177/026119290303100306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of the two studies presented in this paper was to further improve the predictability of the original Multicentre Evaluation of In Vitro Cytotoxicity (MEIC) in vitro test battery for acute systemic toxicity. In the first study, whether a protein-free cytotoxicity assay could improve the prediction of human acute systemic toxicity was investigated. The cytotoxicity of 39 MEIC reference chemicals was measured by the neutral red uptake inhibition test after 30 minutes in phosphate-buffered saline (PBS), with hepatoma-derived Fa32 cells. The results were compared with the corresponding values obtained in complete culture medium, including 10% fetal calf serum. Mercuric chloride and hexachlorophene were much more cytotoxic in PBS, as was the case, to a lesser extent, for seven other chemicals. Potassium cyanide and eight other chemicals were less cytotoxic in PBS than in complete culture medium, probably because of poor physiological conditions. The correlation between the cytotoxicity measured in PBS and human acute toxicity was rather low, but became of the same order as for other assays, when mercuric chloride and hexachlorophene were withdrawn from the comparison. In the second study, modelling of human lethal blood concentrations by using the results of the three cell line tests of the original MEIC test battery were complemented by logP (octanol-water partition coefficient) values. The introduction of logP into the modelling did not improve the correlations, but some improvement of both R(2) and Q(2) was obtained by expanding the logP values with logP(2) values. The highest R(2) (0.84) and Q(2) (0.80) values were obtained for a model in which both experimental and calculated (ambiguous) logP values were used. When only experimental logP values were used, the corresponding values were 0.80 and 0.78. These two studies showed that including protein binding and the partition of chemicals in the MEIC in vitro test battery is important, in order to improve the predictability of the results obtained.
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Cytotoxicity of the dicarboximide fungicides, vinclozolin and iprodione, in rat hepatoma-derived Fa32 cells. Altern Lab Anim 2005; 32:369-73. [PMID: 15651921 DOI: 10.1177/026119290403200408] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Dicarboximide fungicides are widely used to control various fungal species. Their primary action is not known, due to a lack of knowledge concerning the mechanism of action of the dicarboximide group. The cytotoxicities of vinclozolin and iprodione in rat hepatoma-derived Fa32 cells were investigated. Cytotoxicity was measured by neutral red uptake inhibition after treatment for 24 hours. Iprodione was more toxic than vinclozolin. Vinclozolin was less toxic in glutathione-depleted cells than in control cells. This was also true for iprodione at lower concentrations, but iprodione became more toxic at higher concentrations. Both the fungicides increased the endogenous glutathione content by 20% after 1 hour. After 24 hours, the glutathione content was doubled by vinclozolin, but was not affected by iprodione. No effect on glutathione S-transferase activity or reactive oxygen species formation could be observed. Cytochrome P450-dependent ethoxyresorufin-O-deethylase and pentoxyresorufin-O-depentylase activities were moderately activated by iprodione and strongly activated by vinclozolin. A glutathione-related cytochrome P450-dependent metabolic attack of vinclozolin and iprodione could be responsible for their cytotoxicity in Fa32 cells. Further research is needed to fully elucidate these (or other) mechanisms.
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Evidence for delayed cytotoxicity effects following exposure of rat hepatoma-derived Fa32 cells: implications for predicting human acute toxicity. Toxicol In Vitro 2003; 17:797-801. [PMID: 14599480 DOI: 10.1016/s0887-2333(03)00124-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The delayed cytotoxicity of the Multicentre Evaluation of In vitro Cytotoxicity (MEIC) reference chemicals was investigated in rat hepatoma-derived Fa32 cells. The cells were treated for 24 h with the test chemicals, and were than further cultured for 5 days in normal culture medium. The cytotoxicity was measured by the neutral red uptake inhibition, and the results were quantified by determining the NI50del. This is the concentration of test compound required to decrease the neutral red uptake with 50% compared with control cells. The results were compared with the acute NI50, the corresponding value measured immediately after 24 h treatment of the cells. On a total of 44 chemicals, nine showed delayed cytotoxicity (NI50del lower than or equal to NI50), 11 a probably delayed, and 24 no delayed cytotoxicity (NI50del more than 1.5 x NI50). When the NI50del was compared with human toxicity, a correlation coefficient r2=0.761 was obtained. For the same series of 44 chemicals this correlation was clearly higher than that for human hepatoma-derived Hep G2 cells (r2=0.695). The Hep G2 assay was the best acute in vitro assay for the prediction of human toxicity within the MEIC study. Consequently, the delayed cytotoxicity assay on cultured Fa32 cells has the best prediction value so far obtained for the human toxicity.
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The role of oxidative stress on the effect of 1,4,7,10,13,16-hexathiacyclooctadecane on copper and zinc toxicity in HepG2 cells. Hum Exp Toxicol 2003; 22:89-93. [PMID: 12693833 DOI: 10.1191/0960327103ht340oa] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Experiments have shown that 1,4,7,10,13,16-hexathiacyclooctadecane (L3) increased the Cu2+ toxicity on HepG2 cells, whereas the combination Zn(2+)/L3 was less toxic relative to the metal control. In all cases, glutathione (GSH) levels were decreased and vitamins C and E supplementation partially counteracted the increased toxicity in the Cu(2+)/L3-treated cells. The previously observed effects of this hexathiamacrocyclic ligand (L3) on the Cu2+ and Zn2+ toxicity were further investigated by first depleting the intracellular GSH levels by means of L-buthionine S,R-sulphoximine. Combined treatment with Cu(2+)/L3 resulted in complete cell death, whereas for Zn(2+)/L3 no severe effects were observed. Direct measurement of reactive oxygen species (ROS) revealed that Cu2+ induced a high degree of oxidative stress on the cells. This was not the case for Zn2+. The results proved a previously proposed mechanism in which GSH is used to conjugate the metal-ligand complex, but as a result of this, GSH is no longer available for inactivation of ROS. Also, both the intracellular copper and zinc content were determined for each experiment by means of inductively coupled plasma-atomic emission spectroscopy. According to these data, zinc is depleted in Cu(2+)/L3-treated cells, which could have consequences on superoxide dismutase and as a result of this on the amount of oxidative stress.
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Formation of reactive oxygen species in rat hepatoma-derived Fa32 cells to predict human toxicity. Toxicol In Vitro 2002; 16:725-30. [PMID: 12423656 DOI: 10.1016/s0887-2333(02)00081-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cytotoxicity of the MEIC (Multicentre Evaluation of In vitro Cytotoxicity) reference chemicals was investigated by measuring the increased reactive oxygen species (ROS) formation in rat hepatoma-derived Fa32 cells. ROS formation was measured with 2',7'-dichlorodihydrofluorescein diacetate as a fluorescent probe. The results were quantified by determining the ROS50. This is the concentration of test compound required to increase the ROS formation with 50% compared with control cells. An extremely high ROS formation was observed with ferrous sulfate. Of a total of 44 chemicals, an increased ROS formation was observed for 24. This was not the case for the 20 other chemicals. When the ROS formation in Fa32 cells was compared with human toxicity, the correlation coefficient was clearly higher than for human hepatoma-derived Hep G2 cells, at least when the extremely sensitive ferrous sulfate was withdrawn from the comparison. The Hep G2 assay was the best acute in vitro assay for the prediction of human toxicity within the MEIC study. Consequently, the ROS formation assay in Fa32 cells has a high predictive value for human toxicity, with the drawback that only ROS increasing chemicals can be evaluated.
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The effect of hexaaza- and hexathia-macrocyclic ligands on transition metal cytotoxicity in human hepatoma-derived cultured cells. Hum Exp Toxicol 2002; 21:421-7. [PMID: 12412635 DOI: 10.1191/0960327102ht277oa] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The effect of macrocyclic ligands on cytotoxic concentrations of the transition metal ions of copper, zinc, and cadmium was investigated. For this purpose, a hexaaza- [3,6,9,17,20,23-hexaazatricyclo[23.3.1.1(11,15)] triaconta-1(29),11(30),12,14,25,27-hexaene (L2)] and hexathia-chelating ligand [1,4,7,10,13,16-hexathiacyclooctadecane (L3)] were used in the human hepatoma-derived HepG2 cell line. The cytotoxicity was measured by the neutral red uptake inhibition assay. First, the NI50 of the ligands, i.e., the concentration of the ligand inducing a 50% inhibition in neutral red uptake compared to control cells, was determined. In several metal/ligand combination experiments, the effects for L2 were difficult to interpret, whereas for L3 in combination with copper ions, a severe increase -- and for zinc ions, a significant decrease of cell toxicity -- relative to the metal control was observed. To further examine the different effects observed with L3 in combination with, respectively, Cu2+ and Zn2+, the glutathione (GSH) content was measured. The relative GSH content decreased as the concentration of L3 increased. It was proposed that the increased toxicity of the combination Cu(2+)/L3 could be caused by the depletion of GSH and a subsequent inability to scavenge the produced reactive oxygen species (ROS). This hypothesis was supported by experiments during which vitamin E or C was added to the Cu(2+)/L3 system.
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Abstract
Amino alcohols are used as emulsifying agents in dry-cleaning soaps, wax removers, cosmetics, paints and insecticides. The cytotoxicities of 12 amino alcohols, which differed in chain length, position of the amino and alcohol groups, and the presence of an additional phenyl group, were determined by the neutral red uptake inhibition assay with normally cultured, glutathione-depleted or antioxidant-enriched Fa32 rat hepatoma-derived cells. Glutathione depletion and antioxidant enrichment were achieved by including 50(M L-buthionine-S,R-sulphoximine (BSO) or 100(M (-tocopherol acetate (vitamin E) in the culture medium for 24 hours before and during the assay. The cytotoxicity of the amino alcohols observed after treatment for 24 hours was expressed as the concentration of compound needed to induce a 50% reduction in neutral red uptake (NI50). The observed NI50 values ranged from 3mM to 30mM. The individual stereoisomers and a racemic mixture of 1-amino-2-propanol exhibited similar cytotoxicities (with normally cultured Fa32 cells, and vitamin E- and BSO-treated cultures). Similar NI50 values for D-(+)-2-amino-1-propanol, 3-amino-1-propanol and the L-, D- or DL- forms of 1-amino-2-propanol, indicated that the position of the amino group had little influence on the cytotoxicities of the amino alcohols. In contrast, the position of the hydroxyl group appeared to play an important role for the toxicity of the compound, as indicated by the significantly different NI50 values for 4-amino-1-butanol and 4-amino-2-butanol. An additional phenyl group greatly increased the cytotoxicity of 2-amino-1,3-propanediol. For most of the compounds, cytotoxicity increased when GSH was depleted, and decreased when the cells were enriched with vitamin E. This indicated that most of the tested chemicals interact with GSH, either directly or indirectly, by processes which generate oxygen free-radicals. Decreased toxicity was found for most of the chemicals administered to vitamin E-enriched cells, indicating that reactive oxygen species could be involved in the toxicity of the amino alcohols.
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Toxicological evaluation of waste-water samples to appropriately sensitized cultured fathead minnow cells compared with the microtox assay. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2002; 68:253-260. [PMID: 11815796 DOI: 10.1007/s001280246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2001] [Accepted: 08/22/2001] [Indexed: 05/23/2023]
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Cystathionine pathway-dependent cytotoxicities of diethyl maleate and diamide in rat and human hepatoma-derived cell cultures. Altern Lab Anim 2002; 30:61-8. [PMID: 11827570 DOI: 10.1177/026119290203000106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glutathione (GSH) plays a role in many toxicologically important metabolic processes. It was previously established that L-buthionine S,R-sulphoximine (BSO), a specific inhibitor of (- glutamylcysteine synthetase, reduces the GSH content more efficiently in rat (Fa32) than in human (HEp-G2) hepatoma-derived cells. We therefore investigated whether the cystathionase inhibitor propargylglycine (PPG) could further decrease the BSO-induced GSH depletion in HEp-G2 cells. The influence of the cystathionine precursors N-acetylmethionine, methionine and homocysteine on the cytotoxicity of diethyl maleate (DEM) and diamide [1,1'-azobis(N,N-dimethylformamide)] was also investigated. PPG reduced the GSH content in both cell lines. A further GSH decrease in HEp-G2 was obtained when using a BSO + PPG combination containing relatively high concentrations of PPG. BSO diminished the toxicity of PPG. Homocysteine was the most efficacious of the tested cystathionine precursors in increasing the GSH content and reducing the cytotoxicity of DEM and diamide in Fa32 and HEp-G2 cells.
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Neutral red uptake inhibition in adhered and adhering rat hepatoma-derived Fa32 cells to predict human toxicity. J Appl Toxicol 2002; 22:61-5. [PMID: 11807930 DOI: 10.1002/jat.826] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The cytotoxicity of the MEIC (Multicentre Evaluation of In vitro Cytotoxicity) reference chemicals was investigated by measuring the neutral red uptake inhibition in adhered and adhering rat hepatoma-derived Fa32 cells. The adhered cells were seeded and then treated and the adhering cells were treated simultaneously upon seeding. Five of the 44 test chemicals were twofold more toxic in adhering cells; ethylene glycol was 28-fold more toxic and mercuric chloride was 5.2-fold more toxic than in adhered cells. The cytotoxicity of dithiothreitol was altered in the same way as that of ethylene glycol, probably by interacting with calcium. When the neutral red uptake inhibition was compared with human toxicity, the correlation coefficient for adhering cells was almost identical to that obtained previously in human hepatoma-derived Hep G2 cells and slightly higher for adhered cells. The Hep G2 assay was the best acute in vitro assay for the prediction of human toxicity within the MEIC study. An obviously better correlation was obtained when the strong intoxicant mercuric chloride was withdrawn from the comparison, both for the adhered and the adhering cells. Altogether, the results can be integrated very well with the basal cytotoxicity concept.
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Cytotoxicity of the MEIC reference chemicals in antioxidant-enriched, rat hepatoma-derived Fa32 cells. Altern Lab Anim 2001; 29:217-23. [PMID: 11387018 DOI: 10.1177/026119290102900304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Since vitamin E increases the antioxidant status of cells, its influence on cytotoxicity was investigated. The neutral red uptake (NRU) inhibition effects of 39 MEIC reference chemicals were measured after treatment of rat hepatoma-derived Fa32 cells in the presence of vitamin E for 30 minutes. The results were quantified in terms of the NI50, the concentration of test compound required to reduce the NRU by 50%. Sodium chloride was the only chemical that was more toxic in the presence of vitamin E. This effect was related to the concentration of vitamin E in the cell culture medium. A vitamin E dose-related response was also observed for the decreased toxicity of paracetamol and caffeine. Glutathione levels were slightly increased in the presence of vitamin E, which could contribute to the protective effect of vitamin E. Of the remaining chemicals, 50% were less toxic in the presence of vitamin E, but the correlation with the acute human toxicity data of the MEIC study was not improved. The results imply that reactive oxygen species interfere with the toxicity of a high proportion of toxic chemicals. The assay described provides a quick and easy method for checking whether reactive oxygen species contribute to the toxicity of a chemical.
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17
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Glutathione S-transferases of Aulacorthum solani and Acyrthosiphon pisum: partial purification and characterization. Comp Biochem Physiol B Biochem Mol Biol 2001; 129:165-71. [PMID: 11337260 DOI: 10.1016/s1096-4959(01)00329-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Glutathione S-transferases (GST) play an important role in the detoxification of many substances including allelochemicals from plants. Brassicaceae plants contain glucosinolates and emit volatile isothiocyanates which affect the GST system. A comparison of the GST of two aphid species, the generalist Aulacorthum solani found on Brassicaceae and the Fabaceae specialist Acyrthosiphon pisum, was made to try to explain their respective feeding behaviour. Differences of GST were determined among the two aphid species based on purification by affinity chromatography, SDS-PAGE and on kinetic studies. Purification yields using an epoxy-activated Sepharose 6B column were highly different for the two aphid species (18% and 34% for A. solani and A. pisum, respectively). These variations were confirmed by SDS-PAGE. While only a 27-kDa band was observed for A. pisum, two bands of approximately 25-kDa were visualized for the generalist aphid, A. solani. Considering the kinetic results, differences of Km and Vmax were observed following the aphid species when a range of substrates (CDNB and DCNB) and GSH concentrations were tested. Studies on the detoxification enzymes of generalist and specialist herbivores would be undertaken to determine accurately the effect of the host plant on the organisms eating them, particularly in terms of biochemical and ecological advantages.
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Long-term In Vitro Toxicity of 27 MEIC Chemicals on Hep G2 Cells. Altern Lab Anim 2001. [DOI: 10.1177/026119290102900320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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19
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In vitro long-term cytotoxicity testing of 27 MEIC chemicals on Hep G2 cells and comparison with acute human toxicity data. Toxicol In Vitro 2001; 15:153-61. [PMID: 11287174 DOI: 10.1016/s0887-2333(00)00062-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Within the framework of the EDIT (Evaluation guided Development of In vitro Toxicity and toxicokinetic tests) programme, the long-term cytotoxicity of 27 chemicals was investigated on Hep G2 cells. The first step in the experiments was to determine the PI50(24h) of the chemicals. This is the concentration of compound needed to reduce the total protein content by 50% after 24 h of treatment. In the long-term experiments the chemicals were tested in six different concentrations, using the PI50(24h) as maximum concentration. The cells were treated twice a week with the same concentration of test compound and were trypsinised and counted once a week (dynamic culture). The number of cells was compared to the number of cells of the control. Three major long-term cytotoxicity patterns could be distinguished. After 6 weeks, the EC50(6w)s were determined. This is the concentration of compound needed to reduce the number of cells by 50% after 6 weeks of treatment. These values were compared with the PI50(24h). A good correlation was found for the 27 chemicals (r(2)=0.860). After 6 weeks, the concentration of test compound needed to reduce the total cell protein content by 50% after 24 h after 6 weeks of pretreatment of the cells with a particular concentration of test compound was measured: the PI50(24h-6w). For the majority of compounds there is no difference between the PI50(24h) and the PI50(24h-6w). For ethanol, arsenic (III) oxide, verapamil hydrochloride and orphenadrine, the PI50(24h-6w) increased in comparison to the PI50(24h). For some compounds a doseresponse was observed, indicating that the cells have become more resistant or more sensitive. Linear regression analysis revealed a good correlation (r(2)=0.709) between the EC50(6w) and the human acute toxicity. All these data indicate that a good alternative test may be found for predicting the long-term human toxicity.
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20
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Abstract
The cytotoxicity of the MEIC reference chemicals was investigated in rat hepatoma-derived Fa32 cells. The total protein content was measured as an endpoint after exposure times of 30 min and 24 h, both in normal and glutathione-depleted cells. The neutral red uptake inhibition and the MTT conversion were also measured after 30 min. On average, the cytotoxicity was higher in glutathione-depleted cells when compared to normal cells, and was lower after 30 min than after 24 h. Evidence was obtained for lysosomal attack (of five chemicals) or mitochondrial dysfunction (of six chemicals) as the primary intoxication mechanism. Malathion and mercuric chloride belong to both series of chemicals. Good to excellent correlations were observed when the 50% inhibitory concentrations of the six different in vitro assays were compared. When the six in vitro assays in Fa32 cells were compared with the human toxicity, the correlation coefficient was almost always identical to that obtained previously in human hepatoma-derived Hep G2 cells. The latter was the best acute in vitro assay for the prediction of human toxicity within the MEIC study. Altogether the results integrate very well with the basal cytotoxicity concept (Ekwall, B., 1995. The basal cytotoxicity concept. In: Goldberg, A.M., Van Zutphen, L.F.M. (Eds.), The World Congress on Alternatives and Animal Use in the Life Sciences: Education, Research, Testing. Mary Ann Liebert Publishers, New York, pp. 721-725).
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21
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Glutathione-dependent cytotoxicity of the chloroacetanilide herbicides alachlor, metolachlor, and propachlor in rat and human hepatoma-derived cultured cells. Cell Biol Toxicol 2000; 15:325-32. [PMID: 10813365 DOI: 10.1023/a:1007619919336] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Alachlor, metolachlor, and propachlor are widely used chloroacetanilide herbicides. Their cytotoxicity in rat (Fa32) and human (Hep G2) hepatoma-derived cells was investigated, in connection with their influence on the endogenous glutathione (GSH) content, on the xenobiotic-metabolizing phase I enzymes 7-ethoxyresorufin O-deethylase (EROD) and 7-pentoxyresorufin O-depentylase (PROD), and phase II glutathione transferase (GST). The cytotoxicity was measured by the neutral red uptake inhibition assay. The following toxicity range was observed in both cell lines: propachlor > alachlor > metolachlor. When the endogenous GSH content was reduced by pretreatment of the cells with L-buthionine (S,R)-sulfoximine, the cytotoxicity of the herbicides increased strongly in both cell lines. EROD and PROD activities were dose-dependently increased to different degrees in Fa32, as was EROD in Hep G2, but no PROD activity was observed in these cells. The GSH content was not altered after 1 h treatment, and was approximately doubled after 24 h. GST activity was increased in Fa32 cells but not in Hep G2. A comparable cytotoxicity was observed for the investigated chloroacetanilides in both the rat and the human cell lines. Different interactions with xenobiotic-metabolizing phase I and II enzymes were observed, and GSH showed a protective effect against the acetanilides in both cell lines.
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22
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Toxicological Evaluation of Surface-water Samples in Sensitised Cultured Fish Cells Compared with the Microtox® Method. Altern Lab Anim 2000; 28:509-15. [DOI: 10.1177/026119290002800303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A previously described neutral red uptake-inhibition assay on cultured fathead minnow (FHM) fish cells revealed a good correlation with fish toxicity data. The assay was made more sensitive by reducing the number of cells, by using a longer treatment period, and by simultaneous treatment of the cells with sodium dodecyl sulphate and L-buthionine ( S,R)-sulphoximine. The fluorimetrically quantified protein content was then used as the endpoint. The results were compared with toxicity data obtained by the Microtox® method with the bacterium, Vibrio fischeri. A series of 82 surface-water samples were investigated. Cell quantity-dependent and sample concentration-dependent reductions in total protein content were observed. In all, 32 samples were toxic in the FHM assay. Of the seven samples that were shown to be toxic in the Microtox assay, only three were also toxic in FHM cells. No linear relationship was found for the toxicity results obtained with the two methods. Further research to explain the significance of the many positive responses and to identify possible confounding factors will increase the reliability of the sensitised FHM cell assay.
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Glutathione protection against hydrogen peroxide, tert-butyl hydroperoxide and diamide cytotoxicity in rat hepatoma-derived Fa32 cells. Hum Exp Toxicol 1999; 18:627-33. [PMID: 10557015 DOI: 10.1191/096032799678839482] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
1. Several ozonides, peroxides and aldehydes are formed during ozone therapy, recently introduced in medicine. tert-Butyl hydroperoxide (t-BHP), H2O2 and diamide were investigated as model substrate in rat hepatoma-derived Fa32 cells. 2. The cytotoxicity was measured by the neutral red uptake inhibition assay after 1 h or 24 h treatment. The relative toxicities were quantified by the determination of the NI50. This is the concentration of test compound required to induce an inhibition of 50% in neutral red uptake as compared to the control cells. All test chemicals were more toxic after 24 h than after 1 h. 3. The influence of the glutathione (GSH) alteration on the cytotoxicity was measured by treating the cells with 2-oxo-4-thiazolidine carboxylic acid (OTC) or L-buthionine sulfoximine (BSO). OTC increased the endogenous GSH content in the cells. BSO pretreatment strongly decreased the NI50 of the three chemicals. OTC pretreatment increased the NI50 of H2O2 but not of t-BHP and diamide. This can be explained by the strong GSH-depletion after 1 h by t-BHP and diamide, which contrasted with a weak GSH-depletion by H2O2 after the same time period. 4. The three test chemicals increased the endogenous GSH content after 24 h. t-BHP and H2O2, but not diamide, increased the total GSH transferase (GST) activity. Several alterations of the GST subunits were observed. Most striking was the increase of class alpha GST subunits, also for diamide. 5. Since H2O2 and t-BHP are ozone metabolites thought to be responsible for the therapeutic effects of well-dosed ozone, the results show that Fa32 cells can be used as a valuable alternative model system for studying the effects encountered in human ozone therapy.
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24
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Effects of Inducers of Drug Metabolism on Cytosolic Glutathione S-transferase Activity in Rat Hepatoma-derived Fa32 Cells. Altern Lab Anim 1998. [DOI: 10.1177/026119299802600409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Established Fa32 cells, derived from a rat hepatoma, were investigated for their glutathione S-transferase (GST) induction capacity, which is an important characteristic of the detoxification capacity in normal liver. The cells were exposed to inducers of drug metabolism for 3 days in complete medium (containing 10% fetal calf serum). Neither dimethyl sulphoxide nor dimethyl formamide could be used as a vehicle to transport the inducers into the cells, because they also interacted with GST. Phenobarbital, butylated hydroxyanisole, allyl isothio-cyanate and dimethyl fumarate (but not fumaric acid) all effectively increased the total specific GST activity. None of the test chemicals produced a very pronounced induction of specific GST subunits, but subunit 2 and subunit 8 were increased more than the others. The effects of inducers of drug metabolism on the GST activity in Fa32 cells are comparable with those in rat liver. These cells can therefore be used as a valuable alternative model for GST-dependent metabolic interactions in rat liver.
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25
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Effects of Inducers of Drug Metabolism on Cytosolic Glutathione S-transferase Activity in Rat Hepatoma-derived Fa32 Cells. Altern Lab Anim 1998; 26:405-411. [PMID: 26042429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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26
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Increased cytotoxic sensitivity of cultured FHM fish cells by simultaneous treatment with sodium dodecyl sulfate and buthionine sulfoximine. CHEMOSPHERE 1998; 36:1263-1274. [PMID: 9493326 DOI: 10.1016/s0045-6535(97)00372-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A previously described neutral red uptake inhibition assay on cultured fathead minnow (FHM) fish cells revealed a good correlation with fish toxicity data (Brandao et al., 1992) for a series of 50 test compounds, belonging to completely different chemical classes. The major drawback was the lower sensitivity of the cytotoxicity assay. Aiming at a higher sensitivity the assay was adapted by reducing the cell number, by a longer treatment period, and by simultaneous treatment with sodium dodecyl sulfate and buthionine sulfoximine (BSO). The fluorimetrically measured protein content was chosen as the endpoint. The endogenous glutathione (GSH) content was reduced by 54% of the test chemicals, confirming the importance of GSH in detoxification processes. Higher sensitivity was, at least partly, obtained by treating the FHM cells with BSO, reducing the GSH content to 22% of that in control cells. The cytotoxicity of the 50 chemicals was measured using the modified more sensitive assay. Although some exceptions were observed, this new assay is at least one order of magnitude more sensitive. Toxicity values comparable with fish toxicity data were obtained, making the assay sensitive enough to measure the toxicity of environmental water samples.
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27
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Abstract
Protection against xenobiotic insult, including cancer chemoprotection, can be achieved by a variety of natural and synthetic compounds belonging to over 20 different classes of chemicals. They all induce or activate drug-metabolizing enzymes. The discovery of a new class of activator is currently reported. Sodium fluoride activated the phase I ethoxyresorufin-O-deethylase (to 240%) and pentoxyresorufin-O-depentylase (to 156%), and the phase II glutathione transferase to 120% of the basal activities in rat hepatoma-derived Fa32 cells. It is, therefore, a bifunctional enzyme activator. A time- and concentration-dependent activation was observed. A possible impact of the daily fluoride uptake from drinking water is suggested.
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Comparative cytotoxicity of 5-aminosalicylic acid (mesalazine) and related compounds in different cell lines. Cell Biol Toxicol 1997; 13:445-51. [PMID: 9352122 DOI: 10.1023/a:1007423911613] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Nonsteroidal anti-inflammatory drugs can cause serious side-effects such as tubulo-interstitial nephritis. Mesalazine (5-ASA, 5-aminosalicylic acid) is used for the treatment of colitis ulcerosa, Crohn disease, and other diseases; it has been found to induce necrosis of both proximal convoluted tubules and renal papillaries. The comparative cytotoxicity of 3-, 4-, and 5-aminosalicylic acid, acetylsalicylic acid (AcSA), and the parent compound salicylic acid (SA) was investigated for the free acids and for their sodium salts. The interaction with endogenous glutathione (GSH) was also investigated. Four established cell lines were used: MDCK, LLC-PK1, NRK as renal cells, and HepG2 as hepatic cells. The free acid compounds were less toxic than their corresponding salts. Acidic 5-ASA was the most toxic of the three isomers in MDCK and LLC-PK1 cells, while NRK and HepG2 were more susceptible to acidic 3-ASA. Addition of NaOH modified the relative toxicity of 3-ASA and 5-ASA. The LLC-PK1 and HepG2 cells were more sensitive to the test chemicals as their salts than were the NRK and MDCK cells. SA and 5-ASA decreased the GSH content in renal cells and increased it in HepG2. GSH depletion with L-buthionine-(S,R)-sulfoximine enhanced the toxicity only for SA in NRK and for 5-ASA and AcSA in HepG2. No correlation between endogenous GSH and the susceptibility of MDCK and LLC-PK1 to the test compounds was observed. The results suggest that no typical nephrotoxic effect occurred. No explanation could be found for the tubulo-interstitial nephritis caused by 5-ASA therapy.
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Purification and characterisation of the soluble glutathione S-transferase isoenzymes in rat kidney derived NRK cells. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1997; 41:1013-23. [PMID: 9137833 DOI: 10.1080/15216549700202081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Glutathione S-transferase (GST) enzymes are toxicologically important from many points of view. Rat kidney derived established NRK cells were mass cultured for the isolation of GST isoenzymes. These were enriched by affinity chromatography and separated by chromatofocusing and HPLC. Exactly the same major GST subunits were found in NRK cells as in the rat kidney. Strong evidence was also found for the presence of an aberrant form of GST 7-7, as was described in rat kidney. A very good correlation between the NRK GST and rat kidney, and especially cis-platinum treated kidney, was found. It is concluded that NRK cells can be considered as a valuable alternative tool for in vitro research of rat kidney phenomena, especially when toxicological interactions are investigated.
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30
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25 The cytotoxicity of aristolochic acid in the MDCK and LLC-PK1 renal cell lines. Cell Biol Toxicol 1996. [DOI: 10.1007/bf00438197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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31
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Correlation between the in vitro cytotoxicity of inorganic metal compounds to cultured fathead minnow fish cells and the toxicity to Daphnia magna. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1996; 57:107-110. [PMID: 8661467 DOI: 10.1007/s001289900162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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32
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Isolation and characterisation of the class alpha, mu and pi glutathione transferases in LLC-PK1 and pig kidney. Comp Biochem Physiol B Biochem Mol Biol 1996; 114:261-7. [PMID: 8761174 DOI: 10.1016/0305-0491(96)00002-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Glutathione S-transferase (GST) isoenzymes from pig kidney cortex and LLC-PK1 (an established cell line derived from the pig proximal tubule) were purified by affinity chromatography, anionic and cationic chromatofocusing. Purification revealed nine isoenzymes in the pig kidney cortex and five isoenzymes in the LLC-PK1 cell line. SDS-polyacrylamide gel electrophoresis showed that the pig kidney cortex isoenzymes were homo- or heterodimeric; LLC-PK1 isoenzymes, however, were homodimeric. Isoenzymes from pig and LLC-PK1 showed a higher affinity towards glutathione. The isoenzymes were further characterised and divided into the different GST classes by studying specific inhibitors, specific substrates and immunological properties. Pig GSTs belong to class alpha, mu and pi. The GSTs in LLC-PK1 cells, on the other hand, belong to class pi and mu. The isoenzyme pattern in LLC-PK1 cells indicates the dedifferentiation of this particular cell line compared with the pig kidney cortex.
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The cytosolic glutathione S-transferase isoenzymes in the dog kidney cortex as compared with the corresponding MDCK renal cell line. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1311:93-101. [PMID: 8630335 DOI: 10.1016/0167-4889(95)00200-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cytosolic glutathione S-transferase (GST) (EC 2.5.1.18) isoenzymes of dog kidney and MDCK (an established dog renal cell line) were purified and studied. Specific GST activity was 248 and 317 nmol/min/mg protein, for dog and MDCK, respectively. Cytosolic GST was only partially purified by glutathione affinity chromatography, a substantial amount (43% and 84% for dog kidney and MDCK, respectively) of the GST activity was found in the flow-through fraction. Affinity bound GST was separated into 6 and 3 isoenzymes by anionic chromatofocusing for dog and MDCK, respectively. Flow-through GST was purified by gel filtration, anion exchange chromatography and anionic chromatofocusing showing only one GST isoenzyme, with distinct features from the affinity bound GST, for both dog and MDCK. The isoenzymes were characterized by their kinetic properties, subunit composition, specific substrates and inhibitors and immunoblot. The major dog GSTs (DII, DIV and DVI) correspond to the MDCK isoenzymes (MI, MII and MIII). Comparable pI values, a comparable affinity towards GSH and comparable sensitivities towards the inhibitors N-ethylmaleimide (NEM), triphenyltin chloride, cibacron blue and hematin were observed for the corresponding isoenzymes: DII and MI, DIV and MII, DVI and MIII. Co-electrophoresis showed that the subunit composition was identical for DII and MI, and for DIV and MII. Inhibitor and substrate sensitivities showed that the affinity bound GSTs belong to class pi and mu, the presence of class pi was confirmed by immunoblot analysis. One homodimeric GST isoenzyme was observed in the dog kidney and MDCK flow-through. Both dog and MDCK isoenzyme have a nearly neutral pI, a high affinity towards CDNB and an equal sensitivity towards triphenyltin chloride, cibacron blue and hematin. However, based on inhibitor studies and immunoblot, this isoenzyme could not be attributed to an identified GST class. The overall isoenzyme pattern of dog and MDCK affinity bound and flow through GST is comparable. The dog and MDCK affinity bound GSTs have similar characteristics and all belong to class mu or pi.
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Mutagenic activation of aromatic amines by a human hepatoma cell (Hep G2) supernatant tested by means of Salmonella typhimurium strains with different acetyltransferase activities. Mutat Res 1995; 335:219-27. [PMID: 8524336 DOI: 10.1016/0165-1161(95)00024-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The study was carried out to characterize hepatoma cells (Hep G2) as activation system relevant to man and to investigate which are the tester strains most suitable for the mutagenic assay of aromatic amines. A supernatant prepared from the human hepatoma cell line Hep G2 was used to activate benzidine, 2-aminofluorene (2-AF) and 2-acetylaminofluorene (2-AAF) in the Salmonella typhimurium reversion assay. Activation by Hep G2 supernatant was studied with increasing concentrations of the three compounds, in tester strains TA98, YG1024, DJ400 and DJ460. Benz[alpha]anthracene (BA) pretreatment of cells increases the mutagenicity of benzidine in strains YG1024, DJ460 and DJ400. Activation of 2-AAF and 2-AF was observed in strains YG1024, DJ400 and, at the highest tested dose, in DJ460. These results were compared with those obtained with S9 from control and Aroclor 1254 (Aro)-pretreated rat liver. With strain TA98 comparable responses were obtained except for 2-AF which was better activated using rat liver S9. The use of strain YG1024 greatly increases the sensitivity of the response. Strain DJ460 makes it possible to detect activation of 2-AF and 2-AAF by Aro-induced rat liver. These results indicate that Hep G2 supernatant is a useful metabolic activation system of human origin that can be used to replace rat liver S9. An appropriate choice of the Salmonella strain not only can increase the sensitivity of the response, but may also help to overcome certain metabolic shortcomings of the Hep G2 cell line and rat liver S9.
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Abstract
Six mercury compounds [HgCl2 (MC), Hg(CH3COO)2 (MA), Hg(NO3)2 (MN), C2H5HgSC6H4COONa (EMT), C6H5HgOCOCH3 (PMA) and CH3CIHg (MMC)] were studied using two kidney cell lines (MDCK and LLC-PK1), primary cultures of human proximal tubular cells (hPTC) and nonrenal cell lines (SAOS and Hep G2). Cell damage was measured with four different tests: neutral red uptake, mitochondrial dehydrogenase activity (MTT conversion), thymidine incorporation and protein content. Relative toxicity was established by the determination of the concentration of test compound inducing a 50% reduction of the parameter considered (EC50 value). Two groups could be distinguished: PMA, EMT and MMC are one order of magnitude more toxic than MC, MN and MA. Cellular uptake was measured by the HPLC-hybrid generation AAS after 24 hours treatment with 1.5 microM MC, MMC, PMA or EMT in MDCK cells, revealing Hg concentrations of 42.8 +/- 2.5 ng/mg protein for MC, 596.9 +/- 87.8 ng/mg protein for MMC, 269.8 +/- 75.7 ng/mg protein for PMA and of 115.9 +/- 25.2 ng/mg protein for EMT. Cytotoxicity was positively correlated with cellular uptake. The effect of the cellular GSH content on the toxicity of mercury was studied using the GSH synthesis inhibitor L-buthionine sulfoximine (BSO). In all cases an enhanced cytotoxicity was observed after BSO treatment. 2-Oxo-4-thiazolidine carboxylic acid (OTC) was used as a substrate for the GSH synthesis. Although OTC did not enhance the GSH content, the cytotoxicity of MC, MN and MA decreased significantly, no changes were observed for the other mercurials.(ABSTRACT TRUNCATED AT 250 WORDS)
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The influence of picolines on glutathione transferase activity and subunit composition in human liver derived Hep G2 cells. Biochem Pharmacol 1994; 48:1976-8. [PMID: 7986210 DOI: 10.1016/0006-2952(94)90597-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hep G2 cells, an established cell line derived from a human hepatoma, have retained a number of hepatocytic phase I and II reactions. The influence of picolines (2-, 3- and 4-methylpyridine), related compounds and some classical enzyme inducers on specific glutathione transferase (GST) activity and its subunit composition in Hep G2 cells was investigated. Increased GST activity was observed for rifamycin, phenobarbital, pyrazine and the picolines, of which the 4-isomer was the strongest inducer. The GST subunits were analysed by HPLC. GSTP1, GSTM1a, GSTA1 and GSTA2 were present in control Hep G2 cells. GSTM1a disappeared or was strongly reduced under the influence of the test chemicals. All GST increases were due to augmented GSTA1 expression. Thus, picolines stimulate GST activity in Hep G2 cells by influencing the class alpha GSTA1.
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37
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Abstract
This study was designed to compare the cytotoxic concentrations of chemicals, determined with three independent in vitro cytotoxicity testing protocols, with each other and with established animal LD50 values, and against human toxic concentrations for the same chemicals. Ultimately, these comparisons allow us to evaluate the potential of in vitro cell culture methods for the ability to screen a variety of chemicals for prediction of human toxicity. Each laboratory independently tested 50 chemicals with known human lethal plasma concentrations and LD50 values. Two of the methods used monolayer cell cultures to measure the incorporation of radiolabeled amino acids into newly synthesized proteins and cellular protein content, while the third technique used the pollen tube growth test. The latter is based on the photometric quantification of pollen tube mass production in suspension culture. Experiments were performed in the absence or presence of increasing doses of the test chemical, during an 18- to 24-h incubation. Inhibitory concentrations were extrapolated from concentration-effect curves after linear regression analysis. Comparison of the cytotoxic concentrations confirms previous independent findings that the experimental IC50 values are more accurate predictors of human toxicity than equivalent toxic blood concentrations (HETC values) derived from rodent LD50s. In addition, there were no conclusive statistical differences among the methods. It is anticipated that, together, these procedures can be used as a battery of tests to supplement or replace currently used animal protocols for human risk assessment.
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Metabolic activation by a supernatant from human hepatoma cells: a possible alternative in mutagenic tests. Mutat Res 1993; 292:199-204. [PMID: 7692257 DOI: 10.1016/0165-1161(93)90148-s] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The supernatant from human Hep G2 hepatoma cells was examined for typical enzymatic activities involved in the metabolism of xenobiotics. Neither cytochrome P-450 nor b5 was detectable, but associated enzymatic activities were found especially after induction with hydrocortisone (HC) and benzanthracene (BA) suggesting that this Hep G2 supernatant contains cyt P-450 IA1 and IA2. Other critical enzymes are also present, but, as expected, at lower activities than in Aroclor 1254 rat liver S9, except for NADH and NADPH cytochrome c reductase. Results of the Ames test indicate that the induced Hep G2 supernatant is a suitable activator for the evaluation of genotoxicity of indirect mutagens.
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Characterization of the major cytosolic glutathione transferase in two monkey kidney derived cell lines. Cell Biol Int 1993; 17:625-6. [PMID: 8348123 DOI: 10.1006/cbir.1993.1110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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40
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Long-term Cytotoxicity Testing of the First Twenty MEIC Chemicals by the Determination of the Protein Content in Human Embryonic Lung Cells. Altern Lab Anim 1992. [DOI: 10.1177/026119299202000220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Within the framework of the MEIC (the multicentre evaluation of in vitro cytotoxicity) programme, the long-term cytotoxicity of the first twenty MEIC chemicals was investigated on MRC-5 cells. After treatment of the cells with each chemical for six weeks, the PI50 value was determined. The PI50 is the concentration (mM) of test compound required to induce a 50% reduction in total cell protein content. The results were compared with the acute PI50 values previously measured after treatment for 24 hours with the same compounds in Hep G2 cells. A good correlation between these two sets of data (r2= 0.94) was observed, with the exception of digoxin. Together with other preliminary MEIC validation results, this study indicates that a good alternative cytotoxicity test may be found for the prediction of human long-term toxicity.
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Soluble glutathione transferases in the mouse hepatoma derived established BW7756 cell line. CELL BIOLOGY INTERNATIONAL REPORTS 1991; 15:345-6. [PMID: 1878978 DOI: 10.1016/0309-1651(91)90172-f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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42
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Glutathione transferase activity in some flagellates and amoebae, and purification of the soluble glutathione transferases from Acanthamoeba. BIOCHEMISTRY INTERNATIONAL 1990; 22:593-600. [PMID: 2078188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Glutathione transferase (GST) enzymes are toxicologically important from many points of view. Nine protozoans were investigated here for their GST content. Six aerobic amoebae had very different specific GST activities, but an anaerobic amoeba and two anaerobic flagellates did not have any GST activity, suggesting that the peroxidase activity of GST is an evolutionarily important property for aerobic organisms. The soluble GST isoenzymes of Acanthamoeba culbertsoni and A. polyphaga were purified and partially characterized. The same two cationic and one anionic GST isoenzyme were found in both Acanthamoeba ssp., while A. culbertsoni had one more cationic isoenzyme. It is concluded that GST in aerobic amoebae can play an important role in detoxication.
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Selective elution of soluble rat liver glutathione transferases from a glutathione-Sepharose affinity column. JOURNAL OF CHROMATOGRAPHY 1990; 530:263-71. [PMID: 2079502 DOI: 10.1016/s0378-4347(00)82330-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Glutathione transferases (GST) are dimeric enzymes that take part in many detoxification processes. A previous report described the use of a glutathione-Sepharose affinity matrix for the purification of human liver GST. The method involved the use of 5 mM glutathione in a high pH buffer, and the yields were nearly 100%. This method and adapted techniques have now been applied to rat liver GST. Selective GST elution can be obtained in several different ways: by stepwise change of the pH and/or glutathione concentration, and by linear gradient elution. Gel electrophoresis showed, however, that none of the fractions contained pure GST isoenzymes. Also, less than 50% of the total rat liver GST was eluted with 5 mM glutathione, in contrast to the results with human liver GST. A glutathione concentration of 30 mM is necessary for quantitative desorption of rat liver GST from a glutathione-Sepharose column.
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In vitro interaction of mercury, copper (II) and cadmium with human glutathione transferase pi. RESEARCH COMMUNICATIONS IN CHEMICAL PATHOLOGY AND PHARMACOLOGY 1990; 69:99-102. [PMID: 2218073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The in vitro interaction of mercury, copper (II) and cadmium with human glutathione transferase (GST) pi was studied using reduced glutathione (GSH) and 1-chloro-2,4-dinitrobenzene as substrate. Tumor specific human GST pi was isolated from the human hepatoma derived PLC/PRF/5 cell line. The inhibition of the GST pi activity was dose dependent. Kinetic studies never revealed competitive inhibition. A parabolic inhibition was found with GSH as the variable substrate. The heavy metals are spontaneously conjugated with GSH and cysteine, but interact with GST pi by direct binding to this protein. This binding could have a protective function against heavy metals.
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The EYTEX™ System and the Neutral Red Uptake Inhibition Assay in Cultured Hep G2 Cells as Alternative Methods for In Vivo Eye Irritation Following the EEC Protocol. Altern Lab Anim 1990. [DOI: 10.1177/026119299001700406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The neutral red uptake inhibition assay and the EYTEX™ system were investigated as alternative methods for the assessment of eye irritation, determined according to the EEC protocol. The 17 test chemicals used were mainly organic solvents. The xenobiotics were applied to Hep G2 cells for 24 hours at different concentrations. Neutral red uptake inhibition was then measured. The results are expressed as the NI50 value, which is the concentration of test compound required to induce a 50% reduction in neutral red uptake. The same chemicals were also tested as coded samples by the EYTEX™ test according to the manufacturer's directions. A nearly identical quantitative correlation was found for both in vitro methods with corneal opacity scores: r = 0.84 for EYTEX™ scores and r = 0.83 for log NI50, expressed in μg/ml. Whilst these correlations are certainly not perfect, it is clear that both in vitro methods can be used as valuable prescreening methods.
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Long-term buthionine-sulfoximine-mediated toxicity in cultured hepatoma cell lines. RESEARCH COMMUNICATIONS IN CHEMICAL PATHOLOGY AND PHARMACOLOGY 1990; 67:423-6. [PMID: 2160706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The glutathione (GSH) biosynthesis inhibitor L-buthionine-S,R-sulfoximine (BSO) was applied at 100 microM to hepatoma cells in culture for periods up to 4 weeks. PLC/PRF/5 cells grew normally for 4 weeks, the GSH content remaining at a 12% level, but all Hep G2 cells died after 3 weeks, with a gradually decrease in GSH. BSO did not interfere with the trypsinization procedure. Simultaneous application of GSH with BSO for 3 days at least partly inhibited the BSO toxicity in the same cells and in Fa32 cells, but BW1 cells were not sensitive to BSO. GSH depletion was the reason of long-term toxicity of BSO. It is concluded that BSO should be used with great care as an inhibitor of GSH biosynthesis in long-term therapy.
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Identification of soluble glutathione transferases in the rat hepatoma derived established Fa32 cell line. CELL BIOLOGY INTERNATIONAL REPORTS 1989; 13:967-9. [PMID: 2605649 DOI: 10.1016/0309-1651(89)90080-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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48
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Evaluation of a non-invasive human and an in vitro cytotoxicity method as alternatives to the skin irritation test on rabbits. Contact Dermatitis 1989; 21:239-44. [PMID: 2598649 DOI: 10.1111/j.1600-0536.1989.tb03202.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
5 substances were investigated for their primary irritant effect by means of different protocols. The cutaneous blood flow values (CBFV) were measured in humans: in a 1st series of experiments 12 h after application of the pure substances for 48 h and in a 2nd series of experiments 1, 24, 48 and 72 h after application of the 10% diluted substances (subclinical concentration) for 3 h. Rabbit skin erythema scores were obtained 1, 24, 48 and 72 h after application of the undiluted substances for 4 h. The uridine uptake inhibition assay on KB cells was included as a cytotoxicity test. Results obtained for both protocols on humans are compared with each other and with the test data obtained on rabbits, and with the cytotoxicity data. Application of the undiluted substances for 48 h on human skin or for only 3 h at a 10% dilution resulted in the same ranking between the substances. The CBFV in the human correlated very well (r = 0.99) with erythema scores obtained on rabbits. A poor correlation was observed between the in vitro and the in vivo results. From this study, it can be concluded that CBFV measurement is a valid method for the detection of erythema at subclinical concentrations.
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Partial purification and characterization of the soluble glutathione transferase isoenzymes from cultured Hep G2 cells. CELL BIOLOGY INTERNATIONAL REPORTS 1989; 13:585-93. [PMID: 2551510 DOI: 10.1016/0309-1651(89)90108-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Hep G2 cells, an established cell line derived from a human hepatoma, were mass cultured in a cell factory for the isolation of glutathione transferase isoenzymes. These were enriched by affinity chromatography and separated in an anionic and a cationic fraction. They were partially characterized by different kinetic and inhibition parameters. Three different subunits were observed. The results were compared with human liver data. It is concluded that Hep G2 cells can be considered as a valuable alternative tool for in vitro research of human liver phenomena, especially when toxicological interactions are investigated.
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Evaluation of the In Vitro Uridine Uptake Inhibition Assay in Comparison with the In Vivo Eye Irritation Test as Prescribed by the EEC. Altern Lab Anim 1988. [DOI: 10.1177/026119298801500404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In vivo eye irritation tests were carried out on 17 substances (mainly solvents) according to the experimental protocols laid down in the European Community legislation on dangerous substances and the OECD Guidelines. Erythema, chemosis, corneal opacity and iritis were observed and evaluated according to the interpretation rules laid down in EEC legislation. The uridine uptake inhibition assay was carried out on Human Hep G2 cells according to the method of Shopsis & Sathe (1), modified by Dierickx & Martens (2). Inhibition of uridine uptake was expressed as the UI50 (Hep G2 cells, mM). Comparison of the results of our two studies revealed only a poor relationship between the UI50 values and the mean scores obtained for corneal opacity (Spearman rank correlation; r=0.57, p<0.02). Consideration of just the monoalcohols, together with the ketones and the formamides, gave a good linear correlation between the UI50 (Hep G2 cells) and the <<Se>> (r=0.93). If a UI50 value of 50mM is accepted as a limit for classification of irritancy for the eye, no false positives or false negatives are obtained. The UI50 can only be used within strictly defined chemical classes, as a first screening method for detecting possible irritants.
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