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Brian G Lake - One of the best experts on this subject based on the ideXlab platform.
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lack of effect of furfural on unscheduled dna synthesis in the in vivo rat and mouse hepatocyte dna repair assays and in precision cut human Liver Slices
Food and Chemical Toxicology, 2001Co-Authors: Brian G Lake, J.a. Beamand, R.j. Price, A J Edwards, B J Phillips, A B Renwick, T B AdamsAbstract:Abstract The ability of furfural to induce unscheduled DNA synthesis (UDS) in hepatocytes of male and female B6C3F 1 mice and male F344 rats after in vivo administration and in vitro in precision-cut human Liver Slices has been studied. Preliminary toxicity studies established the maximum tolerated dose (MTD) of furfural to be 320 and 50 mg/kg in the mouse and rat, respectively. Furfural was dosed by gavage at levels of 0 (control), 50, 175 and 320 mg/kg to male and female mice and 0, 5, 16.7 and 50 mg/kg to male rats. Hepatocytes were isolated by Liver perfusion either 2–4 h or 12–16 h after treatment, cultured in medium containing [ 3 H]thymidine for 4 h and assessed for UDS by grain counting of autoradiographs. Furfural treatment did not produce any statistically significant increase or any dose-related effects on UDS in mouse and rat hepatocytes either 2–4 h or 12–16 h after dosing. In contrast, UDS was markedly induced in mice and rats 2–4 h after treatment with 20 mg/kg dimethylnitrosamine and 12–16 h after treatment of mice and rats with 200 mg/kg o -aminoazotoluene and 50 mg/kg 2-acetylaminofluorene (2-AAF), respectively. Precision-cut human Liver Slices from four donors were cultured for 24 h in medium containing [ 3 H]thymidine and 0–10 m m furfural. Small increases in the net grain count (i.e. nuclear grain count less mean cytoplasmic grain count) observed with 2–10 m m furfural were not due to any increase in the nuclear grain count. Rather, it was the result of concentration-dependent decreases in the mean cytoplasmic grain counts and to a lesser extent in nuclear grain counts, due to furfural-induced cytotoxicity. In contrast, marked increases in UDS (both net grain and nuclear grain counts) were observed in human Liver Slices treated with 0.02 and 0.05 m m 2-AAF, 0.002 and 0.02 m m aflatoxin B 1 and 0.005 and 0.05 m m 2-amino-1-methyl-6-phenylimidazo[4,5- b ]pyridine. This study demonstrates that furfural does not induce UDS in the hepatocytes of male and female B6C3F 1 mice and male F344 rats after oral treatment at doses up to the MTDs. Moreover, human Liver Slice studies suggest that furfural is also not a genotoxic agent in human Liver.
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lack of effect of coumarin on unscheduled dna synthesis in precision cut human Liver Slices
Food and Chemical Toxicology, 1998Co-Authors: J.a. Beamand, R.j. Price, P T Barton, Brian G LakeAbstract:Abstract In this study the effect of coumarin on unscheduled DNA synthesis (UDS) in precision-cut human Liver Slices has been examined. Liver Slices from tissue samples from four donors were cultured for 24 hr in medium containing [ 3 H]thymidine and 0–5.0 m m coumarin using a dynamic organ culture system and processed for autoradiographic evaluation of UDS. As positive controls Liver Slices were also cultured with three known genotoxic agents, namely 0.02 and 0.05 m m 2-acetylaminofluorene (2-AAF), 0.002 and 0.02 m m aflatoxin B 1 (AFB 1 ) and 0.005 and 0.05 m m 2-amino-1-methyl-6-phenylimidazo [4,5- b ]pyridine (PhIP). UDS was quantified as the net grain count in centrilobular hepatocytes and as the percentage of centrilobular hepatocyte nuclei with more than five net grains. Compared with control Liver Slice cultures, treatment with 0.05–5.0 m m coumarin had no effect on UDS. In contrast, treatment with 0.02 and 0.05 m m 2-AAF, 0.002 and 0.02 m m AFB 1 and 0.005 and 0.05 m m PhIP produced significant increases in the net grain counts of centrilobular hepatocytes. The greatest induction of UDS was observed in Liver Slices treated with 0.05 m m PhIP. Treatment with 2-AAF, AFB 1 and PhIP also produced significant increases in the number of centrilobular hepatocyte nuclei with more than five net grains. At the concentrations examined neither coumarin, 2-AAF, AFB 1 nor PhIP had any significant effect on replicative DNA synthesis in 24 hr cultured human Liver Slices. These results demonstrate that coumarin does not induce UDS in cultured human Liver Slices. However, all three positive control compounds produced marked significant increases in UDS, thus confirming the functional viability of the human Liver Slice preparations used in this study. The results of this study suggest that coumarin is not a genotoxic agent in human Liver.
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lack of effect of piperonyl butoxide on unscheduled dna synthesis in precision cut human Liver Slices
Mutation Research\ genetic Toxicology, 1996Co-Authors: J.a. Beamand, Roger J Price, John C Phillips, William H Butler, Denys Glynne G Jones, Tom G Osimitz, Karl L Gabriel, Fred J Preiss, Brian G LakeAbstract:In this study the effect of piperonyl butoxide (PBO) on unscheduled DNA synthesis in precision-cut human Liver Slices has been examined. Liver Slices prepared from tissue samples from five human donors were cultured in medium containing [3H]thymidine and 0–2.5 mM PBO using a dynamic organ culture system. After 24 h the Liver Slices were processed for autoradiographic examination of UDS. As positive controls, Liver Slices were also cultured with three known genotoxic agents, namely 2-acetylaminofluorene (2-AAF), aflatoxin B1 (AFB1) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). UDS was quantified as the net grain count in centrilobular hepatocytes and as the percentage of centrilobular hepatocyte nuclei with >5 and >10 net grains. Compared to control Liver Slice cultures PBO had no effect on UDS. In contrast, treatment with 0.02 and 0.05 mM 2-AAF, 0.002 and 0.02 and 0.02 mM AFB1 and 0.005 and 0.05 mM PhIP produced significant increases in net grain counts of centrilobular hepatocytes. The greatest induction of UDS was observed in Liver Slices treated with 0.05 mM PhIP. Treatment with 2-AAF, AFB1 and PhIP also produced increases in the number of centrilobular hepatocyte nuclei with >5 and >10 net grains. At the concentrations examined neither PBO, 2-AAF nor PhIP had any significant effect on replicative DNA synthesis in 24 h cultured human Liver Slices. In cultured Liver Slices treated with 0.02, but not 0.002, mM AFB1 a significant reduction in the rate of replicative DNA synthesis was observed. These results demonstrate that PBO does not induce UDS in cultured human Liver Slices. However, all three positive control compounds produced marked significant increases in UDS, thus confirming the functional viability of the human Liver Slice
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metabolism of coumarin and 7 ethoxycoumarin by rat mouse guinea pig cynomolgus monkey and human precision cut Liver Slices
Xenobiotica, 1994Co-Authors: Aukje Steensma, J.a. Beamand, David G Walters, R.j. Price, Brian G LakeAbstract:1. The metabolism of 50 μM 7-ethoxycoumarin and 50 μM [3-14C]coumarin has been studied in precision-cut Liver Slices from the male Sprague-Dawley rat, female DBA/2 mouse, male Dunkin-Hartley guinea pig, male Cynomolgus monkey and man.2. In Liver Slices from all five species 7-ethoxycoumarin was metabolized to 7-hydroxycoumarin (7-HC), which was extensively conjugated with D-glucuronic acid and sulphate. In rat and mouse, 7-HC was preferentially conjugated with sulphate, whereas rates of glucuronidation and sulphation were similar in the other three species.3. [3-14C]coumarin was metabolized by Liver Slices from all five species to various polar products and to metabolite(s) that bound covalently to Liver Slice proteins. In Cynomolgus monkey and both human subjects studied, 7-HC was the major metabolite that was conjugated with D-glucuronic acid and sulphate, whereas in rat the major metabolites were products of the 3-hydroxylation pathway and unknown metabolites. Major metabolites in mouse Liver Slices we...
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use of precision cut Liver Slices for studies of unscheduled dna synthesis
Food and Chemical Toxicology, 1994Co-Authors: J.a. Beamand, R.j. Price, S D Blowers, P T Wield, M E Cunninghame, Brian G LakeAbstract:Abstract Precision-cut Liver Slices were prepared from untreated and Aroclor 1254 (ARO)-treated male Sprague-Dawley rats with a Krumdieck tissue Slicer. Liver Slices were cultured for 24 hr in medium containing [ 3 H]thymidine and 0–0.1 m m 2-acetylaminofluorene (2-AAF) using a dynamic organ culture system and processed for autoradiographic evaluation of unscheduled DNA synthesis (UDS). Compared with control (i.e. 0 m m 2-AAF) Liver Slice cultures, 2-AAF produced a concentration-dependent increase in UDS, the effect being more marked in Liver Slices from ARO-treated than from untreated rats. With Liver Slices from untreated rats, 2-AAF produced the greatest increase in UDS in centrilobular hepatocytes. 2-AAF-induced UDS in Liver Slices from ARO-treated rats was most marked in centrilobular hepatocytes but the effect also extended to other areas of the Liver lobule. These results demonstrate that precision-cut Liver Slices may be a valuable alternative in vitro system to hepatocyte cultures for screening chemicals for potential genotoxicity. Unlike hepatocyte cultures, Liver Slices permit the study of zonal differences in UDS. Moreover, this technique could be applied to other tissues and the study of species differences in response.
Sylvie Lagaye - One of the best experts on this subject based on the ideXlab platform.
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adult human Liver Slice cultures modelling of Liver fibrosis and evaluation of new anti fibrotic drugs
World Journal of Hepatology, 2021Co-Authors: Daria Kartashevaebertz, Jesintha Gaston, Loriane Lairmehiri, Pierrephilippe Massault, Olivier Scatton, Jeanchristophe Vaillant, V A Morozov, Stanislas Pol, Sylvie LagayeAbstract:Background Liver fibrosis can result in end-stage Liver failure and death. Aim To examine human Liver fibrogenesis and anti-fibrotic therapies, we evaluated the three dimensional ex vivo Liver Slice (LS) model. Methods Fibrotic Liver samples (F0 to F4 fibrosis stage according to the METAVIR score) were collected from patients after Liver resection. Human Liver Slices (HLS) were cultivated for up to 21 days. Hepatitis C virus (HCV) infection, alcohol (ethanol stimulation) and steatosis (palmitate stimulation) were examined in fibrotic (F2 to F4) Liver Slices infected (or not) with HCV. F0-F1 HLS were used as controls. At day 0, either ursodeoxycholic acid (choleretic and hepatoprotective properties) and/or α-tocopherol (antioxidant properties) were added to standard of care on HLS and fibrotic Liver Slices, infected (or not) with HCV. Expression of the biomarkers of fibrosis and the triglyceride production were checked by quantitative reverse transcription polymerase chain reaction and/or enzyme-linked immunosorbent assay. Results The cultures were viable in vitro for 21 days allowing to study fibrosis inducers and to estimate the effect of anti-fibrotic drugs. Expression of the biomarkers of fibrosis and the progression to steatosis (estimated by triglycerides production) was increased with the addition of HCV and /or ethanol or palmitate. From day 15 of the follow-up studies, a significant decrease of both transforming growth factor β-1 and Procol1A1 expression and triglycerides production was observed when a combined anti-fibrotic treatment was applied on HCV infected F2-F4 LS cultures. Conclusion These results show that the human three dimensional ex vivo model effectively reflects the in vivo processes in damaged human Liver (viral, alcoholic, nonalcoholic steatohepatitis Liver diseases) and provides the proof of concept that the LS examined model permits a rapid evaluation of new anti-fibrotic therapies when used alone or in combination.
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adult human Liver Slice cultures modelling of Liver fibrosis and evaluation of new anti fibrotic drugs
World Journal of Hepatology, 2021Co-Authors: Daria Kartashevaebertz, Jesintha Gaston, Loriane Lairmehiri, Pierrephilippe Massault, Olivier Scatton, Jeanchristophe Vaillant, V A Morozov, Stanislas Pol, Sylvie LagayeAbstract:Adult human Liver Slice cultures: Modelling of Liver fibrosis and evaluation of new anti-fibrotic drugs
J.a. Beamand - One of the best experts on this subject based on the ideXlab platform.
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lack of effect of furfural on unscheduled dna synthesis in the in vivo rat and mouse hepatocyte dna repair assays and in precision cut human Liver Slices
Food and Chemical Toxicology, 2001Co-Authors: Brian G Lake, J.a. Beamand, R.j. Price, A J Edwards, B J Phillips, A B Renwick, T B AdamsAbstract:Abstract The ability of furfural to induce unscheduled DNA synthesis (UDS) in hepatocytes of male and female B6C3F 1 mice and male F344 rats after in vivo administration and in vitro in precision-cut human Liver Slices has been studied. Preliminary toxicity studies established the maximum tolerated dose (MTD) of furfural to be 320 and 50 mg/kg in the mouse and rat, respectively. Furfural was dosed by gavage at levels of 0 (control), 50, 175 and 320 mg/kg to male and female mice and 0, 5, 16.7 and 50 mg/kg to male rats. Hepatocytes were isolated by Liver perfusion either 2–4 h or 12–16 h after treatment, cultured in medium containing [ 3 H]thymidine for 4 h and assessed for UDS by grain counting of autoradiographs. Furfural treatment did not produce any statistically significant increase or any dose-related effects on UDS in mouse and rat hepatocytes either 2–4 h or 12–16 h after dosing. In contrast, UDS was markedly induced in mice and rats 2–4 h after treatment with 20 mg/kg dimethylnitrosamine and 12–16 h after treatment of mice and rats with 200 mg/kg o -aminoazotoluene and 50 mg/kg 2-acetylaminofluorene (2-AAF), respectively. Precision-cut human Liver Slices from four donors were cultured for 24 h in medium containing [ 3 H]thymidine and 0–10 m m furfural. Small increases in the net grain count (i.e. nuclear grain count less mean cytoplasmic grain count) observed with 2–10 m m furfural were not due to any increase in the nuclear grain count. Rather, it was the result of concentration-dependent decreases in the mean cytoplasmic grain counts and to a lesser extent in nuclear grain counts, due to furfural-induced cytotoxicity. In contrast, marked increases in UDS (both net grain and nuclear grain counts) were observed in human Liver Slices treated with 0.02 and 0.05 m m 2-AAF, 0.002 and 0.02 m m aflatoxin B 1 and 0.005 and 0.05 m m 2-amino-1-methyl-6-phenylimidazo[4,5- b ]pyridine. This study demonstrates that furfural does not induce UDS in the hepatocytes of male and female B6C3F 1 mice and male F344 rats after oral treatment at doses up to the MTDs. Moreover, human Liver Slice studies suggest that furfural is also not a genotoxic agent in human Liver.
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lack of effect of coumarin on unscheduled dna synthesis in precision cut human Liver Slices
Food and Chemical Toxicology, 1998Co-Authors: J.a. Beamand, R.j. Price, P T Barton, Brian G LakeAbstract:Abstract In this study the effect of coumarin on unscheduled DNA synthesis (UDS) in precision-cut human Liver Slices has been examined. Liver Slices from tissue samples from four donors were cultured for 24 hr in medium containing [ 3 H]thymidine and 0–5.0 m m coumarin using a dynamic organ culture system and processed for autoradiographic evaluation of UDS. As positive controls Liver Slices were also cultured with three known genotoxic agents, namely 0.02 and 0.05 m m 2-acetylaminofluorene (2-AAF), 0.002 and 0.02 m m aflatoxin B 1 (AFB 1 ) and 0.005 and 0.05 m m 2-amino-1-methyl-6-phenylimidazo [4,5- b ]pyridine (PhIP). UDS was quantified as the net grain count in centrilobular hepatocytes and as the percentage of centrilobular hepatocyte nuclei with more than five net grains. Compared with control Liver Slice cultures, treatment with 0.05–5.0 m m coumarin had no effect on UDS. In contrast, treatment with 0.02 and 0.05 m m 2-AAF, 0.002 and 0.02 m m AFB 1 and 0.005 and 0.05 m m PhIP produced significant increases in the net grain counts of centrilobular hepatocytes. The greatest induction of UDS was observed in Liver Slices treated with 0.05 m m PhIP. Treatment with 2-AAF, AFB 1 and PhIP also produced significant increases in the number of centrilobular hepatocyte nuclei with more than five net grains. At the concentrations examined neither coumarin, 2-AAF, AFB 1 nor PhIP had any significant effect on replicative DNA synthesis in 24 hr cultured human Liver Slices. These results demonstrate that coumarin does not induce UDS in cultured human Liver Slices. However, all three positive control compounds produced marked significant increases in UDS, thus confirming the functional viability of the human Liver Slice preparations used in this study. The results of this study suggest that coumarin is not a genotoxic agent in human Liver.
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lack of effect of piperonyl butoxide on unscheduled dna synthesis in precision cut human Liver Slices
Mutation Research\ genetic Toxicology, 1996Co-Authors: J.a. Beamand, Roger J Price, John C Phillips, William H Butler, Denys Glynne G Jones, Tom G Osimitz, Karl L Gabriel, Fred J Preiss, Brian G LakeAbstract:In this study the effect of piperonyl butoxide (PBO) on unscheduled DNA synthesis in precision-cut human Liver Slices has been examined. Liver Slices prepared from tissue samples from five human donors were cultured in medium containing [3H]thymidine and 0–2.5 mM PBO using a dynamic organ culture system. After 24 h the Liver Slices were processed for autoradiographic examination of UDS. As positive controls, Liver Slices were also cultured with three known genotoxic agents, namely 2-acetylaminofluorene (2-AAF), aflatoxin B1 (AFB1) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). UDS was quantified as the net grain count in centrilobular hepatocytes and as the percentage of centrilobular hepatocyte nuclei with >5 and >10 net grains. Compared to control Liver Slice cultures PBO had no effect on UDS. In contrast, treatment with 0.02 and 0.05 mM 2-AAF, 0.002 and 0.02 and 0.02 mM AFB1 and 0.005 and 0.05 mM PhIP produced significant increases in net grain counts of centrilobular hepatocytes. The greatest induction of UDS was observed in Liver Slices treated with 0.05 mM PhIP. Treatment with 2-AAF, AFB1 and PhIP also produced increases in the number of centrilobular hepatocyte nuclei with >5 and >10 net grains. At the concentrations examined neither PBO, 2-AAF nor PhIP had any significant effect on replicative DNA synthesis in 24 h cultured human Liver Slices. In cultured Liver Slices treated with 0.02, but not 0.002, mM AFB1 a significant reduction in the rate of replicative DNA synthesis was observed. These results demonstrate that PBO does not induce UDS in cultured human Liver Slices. However, all three positive control compounds produced marked significant increases in UDS, thus confirming the functional viability of the human Liver Slice
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metabolism of coumarin and 7 ethoxycoumarin by rat mouse guinea pig cynomolgus monkey and human precision cut Liver Slices
Xenobiotica, 1994Co-Authors: Aukje Steensma, J.a. Beamand, David G Walters, R.j. Price, Brian G LakeAbstract:1. The metabolism of 50 μM 7-ethoxycoumarin and 50 μM [3-14C]coumarin has been studied in precision-cut Liver Slices from the male Sprague-Dawley rat, female DBA/2 mouse, male Dunkin-Hartley guinea pig, male Cynomolgus monkey and man.2. In Liver Slices from all five species 7-ethoxycoumarin was metabolized to 7-hydroxycoumarin (7-HC), which was extensively conjugated with D-glucuronic acid and sulphate. In rat and mouse, 7-HC was preferentially conjugated with sulphate, whereas rates of glucuronidation and sulphation were similar in the other three species.3. [3-14C]coumarin was metabolized by Liver Slices from all five species to various polar products and to metabolite(s) that bound covalently to Liver Slice proteins. In Cynomolgus monkey and both human subjects studied, 7-HC was the major metabolite that was conjugated with D-glucuronic acid and sulphate, whereas in rat the major metabolites were products of the 3-hydroxylation pathway and unknown metabolites. Major metabolites in mouse Liver Slices we...
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use of precision cut Liver Slices for studies of unscheduled dna synthesis
Food and Chemical Toxicology, 1994Co-Authors: J.a. Beamand, R.j. Price, S D Blowers, P T Wield, M E Cunninghame, Brian G LakeAbstract:Abstract Precision-cut Liver Slices were prepared from untreated and Aroclor 1254 (ARO)-treated male Sprague-Dawley rats with a Krumdieck tissue Slicer. Liver Slices were cultured for 24 hr in medium containing [ 3 H]thymidine and 0–0.1 m m 2-acetylaminofluorene (2-AAF) using a dynamic organ culture system and processed for autoradiographic evaluation of unscheduled DNA synthesis (UDS). Compared with control (i.e. 0 m m 2-AAF) Liver Slice cultures, 2-AAF produced a concentration-dependent increase in UDS, the effect being more marked in Liver Slices from ARO-treated than from untreated rats. With Liver Slices from untreated rats, 2-AAF produced the greatest increase in UDS in centrilobular hepatocytes. 2-AAF-induced UDS in Liver Slices from ARO-treated rats was most marked in centrilobular hepatocytes but the effect also extended to other areas of the Liver lobule. These results demonstrate that precision-cut Liver Slices may be a valuable alternative in vitro system to hepatocyte cultures for screening chemicals for potential genotoxicity. Unlike hepatocyte cultures, Liver Slices permit the study of zonal differences in UDS. Moreover, this technique could be applied to other tissues and the study of species differences in response.
R.j. Price - One of the best experts on this subject based on the ideXlab platform.
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lack of effect of furfural on unscheduled dna synthesis in the in vivo rat and mouse hepatocyte dna repair assays and in precision cut human Liver Slices
Food and Chemical Toxicology, 2001Co-Authors: Brian G Lake, J.a. Beamand, R.j. Price, A J Edwards, B J Phillips, A B Renwick, T B AdamsAbstract:Abstract The ability of furfural to induce unscheduled DNA synthesis (UDS) in hepatocytes of male and female B6C3F 1 mice and male F344 rats after in vivo administration and in vitro in precision-cut human Liver Slices has been studied. Preliminary toxicity studies established the maximum tolerated dose (MTD) of furfural to be 320 and 50 mg/kg in the mouse and rat, respectively. Furfural was dosed by gavage at levels of 0 (control), 50, 175 and 320 mg/kg to male and female mice and 0, 5, 16.7 and 50 mg/kg to male rats. Hepatocytes were isolated by Liver perfusion either 2–4 h or 12–16 h after treatment, cultured in medium containing [ 3 H]thymidine for 4 h and assessed for UDS by grain counting of autoradiographs. Furfural treatment did not produce any statistically significant increase or any dose-related effects on UDS in mouse and rat hepatocytes either 2–4 h or 12–16 h after dosing. In contrast, UDS was markedly induced in mice and rats 2–4 h after treatment with 20 mg/kg dimethylnitrosamine and 12–16 h after treatment of mice and rats with 200 mg/kg o -aminoazotoluene and 50 mg/kg 2-acetylaminofluorene (2-AAF), respectively. Precision-cut human Liver Slices from four donors were cultured for 24 h in medium containing [ 3 H]thymidine and 0–10 m m furfural. Small increases in the net grain count (i.e. nuclear grain count less mean cytoplasmic grain count) observed with 2–10 m m furfural were not due to any increase in the nuclear grain count. Rather, it was the result of concentration-dependent decreases in the mean cytoplasmic grain counts and to a lesser extent in nuclear grain counts, due to furfural-induced cytotoxicity. In contrast, marked increases in UDS (both net grain and nuclear grain counts) were observed in human Liver Slices treated with 0.02 and 0.05 m m 2-AAF, 0.002 and 0.02 m m aflatoxin B 1 and 0.005 and 0.05 m m 2-amino-1-methyl-6-phenylimidazo[4,5- b ]pyridine. This study demonstrates that furfural does not induce UDS in the hepatocytes of male and female B6C3F 1 mice and male F344 rats after oral treatment at doses up to the MTDs. Moreover, human Liver Slice studies suggest that furfural is also not a genotoxic agent in human Liver.
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lack of effect of coumarin on unscheduled dna synthesis in precision cut human Liver Slices
Food and Chemical Toxicology, 1998Co-Authors: J.a. Beamand, R.j. Price, P T Barton, Brian G LakeAbstract:Abstract In this study the effect of coumarin on unscheduled DNA synthesis (UDS) in precision-cut human Liver Slices has been examined. Liver Slices from tissue samples from four donors were cultured for 24 hr in medium containing [ 3 H]thymidine and 0–5.0 m m coumarin using a dynamic organ culture system and processed for autoradiographic evaluation of UDS. As positive controls Liver Slices were also cultured with three known genotoxic agents, namely 0.02 and 0.05 m m 2-acetylaminofluorene (2-AAF), 0.002 and 0.02 m m aflatoxin B 1 (AFB 1 ) and 0.005 and 0.05 m m 2-amino-1-methyl-6-phenylimidazo [4,5- b ]pyridine (PhIP). UDS was quantified as the net grain count in centrilobular hepatocytes and as the percentage of centrilobular hepatocyte nuclei with more than five net grains. Compared with control Liver Slice cultures, treatment with 0.05–5.0 m m coumarin had no effect on UDS. In contrast, treatment with 0.02 and 0.05 m m 2-AAF, 0.002 and 0.02 m m AFB 1 and 0.005 and 0.05 m m PhIP produced significant increases in the net grain counts of centrilobular hepatocytes. The greatest induction of UDS was observed in Liver Slices treated with 0.05 m m PhIP. Treatment with 2-AAF, AFB 1 and PhIP also produced significant increases in the number of centrilobular hepatocyte nuclei with more than five net grains. At the concentrations examined neither coumarin, 2-AAF, AFB 1 nor PhIP had any significant effect on replicative DNA synthesis in 24 hr cultured human Liver Slices. These results demonstrate that coumarin does not induce UDS in cultured human Liver Slices. However, all three positive control compounds produced marked significant increases in UDS, thus confirming the functional viability of the human Liver Slice preparations used in this study. The results of this study suggest that coumarin is not a genotoxic agent in human Liver.
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metabolism of coumarin and 7 ethoxycoumarin by rat mouse guinea pig cynomolgus monkey and human precision cut Liver Slices
Xenobiotica, 1994Co-Authors: Aukje Steensma, J.a. Beamand, David G Walters, R.j. Price, Brian G LakeAbstract:1. The metabolism of 50 μM 7-ethoxycoumarin and 50 μM [3-14C]coumarin has been studied in precision-cut Liver Slices from the male Sprague-Dawley rat, female DBA/2 mouse, male Dunkin-Hartley guinea pig, male Cynomolgus monkey and man.2. In Liver Slices from all five species 7-ethoxycoumarin was metabolized to 7-hydroxycoumarin (7-HC), which was extensively conjugated with D-glucuronic acid and sulphate. In rat and mouse, 7-HC was preferentially conjugated with sulphate, whereas rates of glucuronidation and sulphation were similar in the other three species.3. [3-14C]coumarin was metabolized by Liver Slices from all five species to various polar products and to metabolite(s) that bound covalently to Liver Slice proteins. In Cynomolgus monkey and both human subjects studied, 7-HC was the major metabolite that was conjugated with D-glucuronic acid and sulphate, whereas in rat the major metabolites were products of the 3-hydroxylation pathway and unknown metabolites. Major metabolites in mouse Liver Slices we...
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use of precision cut Liver Slices for studies of unscheduled dna synthesis
Food and Chemical Toxicology, 1994Co-Authors: J.a. Beamand, R.j. Price, S D Blowers, P T Wield, M E Cunninghame, Brian G LakeAbstract:Abstract Precision-cut Liver Slices were prepared from untreated and Aroclor 1254 (ARO)-treated male Sprague-Dawley rats with a Krumdieck tissue Slicer. Liver Slices were cultured for 24 hr in medium containing [ 3 H]thymidine and 0–0.1 m m 2-acetylaminofluorene (2-AAF) using a dynamic organ culture system and processed for autoradiographic evaluation of unscheduled DNA synthesis (UDS). Compared with control (i.e. 0 m m 2-AAF) Liver Slice cultures, 2-AAF produced a concentration-dependent increase in UDS, the effect being more marked in Liver Slices from ARO-treated than from untreated rats. With Liver Slices from untreated rats, 2-AAF produced the greatest increase in UDS in centrilobular hepatocytes. 2-AAF-induced UDS in Liver Slices from ARO-treated rats was most marked in centrilobular hepatocytes but the effect also extended to other areas of the Liver lobule. These results demonstrate that precision-cut Liver Slices may be a valuable alternative in vitro system to hepatocyte cultures for screening chemicals for potential genotoxicity. Unlike hepatocyte cultures, Liver Slices permit the study of zonal differences in UDS. Moreover, this technique could be applied to other tissues and the study of species differences in response.
Daria Kartashevaebertz - One of the best experts on this subject based on the ideXlab platform.
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adult human Liver Slice cultures modelling of Liver fibrosis and evaluation of new anti fibrotic drugs
World Journal of Hepatology, 2021Co-Authors: Daria Kartashevaebertz, Jesintha Gaston, Loriane Lairmehiri, Pierrephilippe Massault, Olivier Scatton, Jeanchristophe Vaillant, V A Morozov, Stanislas Pol, Sylvie LagayeAbstract:Background Liver fibrosis can result in end-stage Liver failure and death. Aim To examine human Liver fibrogenesis and anti-fibrotic therapies, we evaluated the three dimensional ex vivo Liver Slice (LS) model. Methods Fibrotic Liver samples (F0 to F4 fibrosis stage according to the METAVIR score) were collected from patients after Liver resection. Human Liver Slices (HLS) were cultivated for up to 21 days. Hepatitis C virus (HCV) infection, alcohol (ethanol stimulation) and steatosis (palmitate stimulation) were examined in fibrotic (F2 to F4) Liver Slices infected (or not) with HCV. F0-F1 HLS were used as controls. At day 0, either ursodeoxycholic acid (choleretic and hepatoprotective properties) and/or α-tocopherol (antioxidant properties) were added to standard of care on HLS and fibrotic Liver Slices, infected (or not) with HCV. Expression of the biomarkers of fibrosis and the triglyceride production were checked by quantitative reverse transcription polymerase chain reaction and/or enzyme-linked immunosorbent assay. Results The cultures were viable in vitro for 21 days allowing to study fibrosis inducers and to estimate the effect of anti-fibrotic drugs. Expression of the biomarkers of fibrosis and the progression to steatosis (estimated by triglycerides production) was increased with the addition of HCV and /or ethanol or palmitate. From day 15 of the follow-up studies, a significant decrease of both transforming growth factor β-1 and Procol1A1 expression and triglycerides production was observed when a combined anti-fibrotic treatment was applied on HCV infected F2-F4 LS cultures. Conclusion These results show that the human three dimensional ex vivo model effectively reflects the in vivo processes in damaged human Liver (viral, alcoholic, nonalcoholic steatohepatitis Liver diseases) and provides the proof of concept that the LS examined model permits a rapid evaluation of new anti-fibrotic therapies when used alone or in combination.
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adult human Liver Slice cultures modelling of Liver fibrosis and evaluation of new anti fibrotic drugs
World Journal of Hepatology, 2021Co-Authors: Daria Kartashevaebertz, Jesintha Gaston, Loriane Lairmehiri, Pierrephilippe Massault, Olivier Scatton, Jeanchristophe Vaillant, V A Morozov, Stanislas Pol, Sylvie LagayeAbstract:Adult human Liver Slice cultures: Modelling of Liver fibrosis and evaluation of new anti-fibrotic drugs