Induction of rat liver microsomal cytochrome P-450 isozymes and epoxide hydrolase by a series of 4′-substituted-2,3,4,5-tetrachlorobiphenyls

Differential modulation of hepatic cytochrome P‐450 enzymes in rat and syrian hamster by 4′‐trifluoromethyl‐2,3,4,5‐tetrachlorobiphenyl

“…In rats, CF3 treatment failed to induce CYP2A8, not expressed in untreated rats, which agrees well with the studies suggesting that this isozyme is specific to the hamster (48). Moreover, it appears that CF3 is the most effective inducing agent of rat CYP2A1 protein, whereas 3MC, PB, or Aroclor 1254 caused only a modest increase in CYP2A1, and its related activity (18,45,49). In microsomes from both control and CF3-treated hamsters, we detected proteins that cross-reacted with antirat CYP2Al.…”

Differential modulation of hepatic cytochrome P‐450 enzymes in rat and syrian hamster by 4′‐trifluoromethyl‐2,3,4,5‐tetrachlorobiphenyl

“…In rats, CF3 treatment failed to induce CYP2A8, not expressed in untreated rats, which agrees well with the studies suggesting that this isozyme is specific to the hamster (48). Moreover, it appears that CF3 is the most effective inducing agent of rat CYP2A1 protein, whereas 3MC, PB, or Aroclor 1254 caused only a modest increase in CYP2A1, and its related activity (18,45,49). In microsomes from both control and CF3-treated hamsters, we detected proteins that cross-reacted with antirat CYP2Al.…”

Identification of a New Mutagenic Polychlorinated Biphenyl Derivative in the Waka River, Wakayama, Japan, Showing Activation of an Aryl Hydrocarbon Receptor-Dependent Transcription

“…Transactivation Activity of 4-Amino-3,3 ‘ -dichloro-5,4 ‘ -dinitrobiphenyl (6) to Human AhR. 4-Amino-3,3‘-dichloro-5,4‘-dinitrobiphenyl 6 has a polychlorinated biphenyl (PCB) moiety, which would be predicted to bind to the human AhR ( − ). Thus, we tested this ability of 6 using a yeast YCM3 in which an AhR−Arnt complex system is expressed.…”

Toxicity Increases in Ice Containing Monochlorophenols upon Photolysis: Environmental Consequences

“…For example, hydroxy-PCBs were shown to act as both estrogens (47) and antiestrogens (48), they can form DNA-adducts (49) (in contrast to parent PCBs which are unlikely to induce DNA damage; 50), and they can also inhibit important enzymes involved in the metabolism of thyroid hormones (51). Photoproducts formed in frozen water samples as well as purified 5-chlorobiphenyl-2,4′-diol had significant potencies to induce AhR-mediated toxicity, which corresponds to the fact that hydroxyderivatives of chlorinated biphenyls are weaker inducers of AhR than parent PCBs (52).…”

Differential modulation of hepatic cytochrome P‐450 enzymes in rat and syrian hamster by 4′‐trifluoromethyl‐2,3,4,5‐tetrachlorobiphenyl

“…In rats, CF3 treatment failed to induce CYP2A8, not expressed in untreated rats, which agrees well with the studies suggesting that this isozyme is specific to the hamster (48). Moreover, it appears that CF3 is the most effective inducing agent of rat CYP2A1 protein, whereas 3MC, PB, or Aroclor 1254 caused only a modest increase in CYP2A1, and its related activity (18,45,49). In microsomes from both control and CF3-treated hamsters, we detected proteins that cross-reacted with antirat CYP2Al.…”

Identification of a New Mutagenic Polychlorinated Biphenyl Derivative in the Waka River, Wakayama, Japan, Showing Activation of an Aryl Hydrocarbon Receptor-Dependent Transcription

“…Transactivation Activity of 4-Amino-3,3 ‘ -dichloro-5,4 ‘ -dinitrobiphenyl (6) to Human AhR. 4-Amino-3,3‘-dichloro-5,4‘-dinitrobiphenyl 6 has a polychlorinated biphenyl (PCB) moiety, which would be predicted to bind to the human AhR ( − ). Thus, we tested this ability of 6 using a yeast YCM3 in which an AhR−Arnt complex system is expressed.…”

Toxicity Increases in Ice Containing Monochlorophenols upon Photolysis: Environmental Consequences

“…For example, hydroxy-PCBs were shown to act as both estrogens (47) and antiestrogens (48), they can form DNA-adducts (49) (in contrast to parent PCBs which are unlikely to induce DNA damage; 50), and they can also inhibit important enzymes involved in the metabolism of thyroid hormones (51). Photoproducts formed in frozen water samples as well as purified 5-chlorobiphenyl-2,4′-diol had significant potencies to induce AhR-mediated toxicity, which corresponds to the fact that hydroxyderivatives of chlorinated biphenyls are weaker inducers of AhR than parent PCBs (52).…”

Differential modulation of hepatic cytochrome P‐450 enzymes in rat and syrian hamster by 4′‐trifluoromethyl‐2,3,4,5‐tetrachlorobiphenyl

“…In rats, CF3 treatment failed to induce CYP2A8, not expressed in untreated rats, which agrees well with the studies suggesting that this isozyme is specific to the hamster (48). Moreover, it appears that CF3 is the most effective inducing agent of rat CYP2A1 protein, whereas 3MC, PB, or Aroclor 1254 caused only a modest increase in CYP2A1, and its related activity (18,45,49). In microsomes from both control and CF3-treated hamsters, we detected proteins that cross-reacted with antirat CYP2Al.…”

Identification of a New Mutagenic Polychlorinated Biphenyl Derivative in the Waka River, Wakayama, Japan, Showing Activation of an Aryl Hydrocarbon Receptor-Dependent Transcription

“…Transactivation Activity of 4-Amino-3,3 ‘ -dichloro-5,4 ‘ -dinitrobiphenyl (6) to Human AhR. 4-Amino-3,3‘-dichloro-5,4‘-dinitrobiphenyl 6 has a polychlorinated biphenyl (PCB) moiety, which would be predicted to bind to the human AhR ( − ). Thus, we tested this ability of 6 using a yeast YCM3 in which an AhR−Arnt complex system is expressed.…”

Toxicity Increases in Ice Containing Monochlorophenols upon Photolysis: Environmental Consequences

“…For example, hydroxy-PCBs were shown to act as both estrogens (47) and antiestrogens (48), they can form DNA-adducts (49) (in contrast to parent PCBs which are unlikely to induce DNA damage; 50), and they can also inhibit important enzymes involved in the metabolism of thyroid hormones (51). Photoproducts formed in frozen water samples as well as purified 5-chlorobiphenyl-2,4′-diol had significant potencies to induce AhR-mediated toxicity, which corresponds to the fact that hydroxyderivatives of chlorinated biphenyls are weaker inducers of AhR than parent PCBs (52).…”