The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform
Ernest Hodgson - One of the best experts on this subject based on the ideXlab platform.
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the role of oxidative enzymes in the metabolism and toxicity of pesticides
1995Co-Authors: Ernest Hodgson, Randy L. Rose, Nancy H. Adams, Nora J Deamer, Mary Beth Genter, Krishnappa Venkatesh, Patricia E. LeviAbstract:Xenobiotics, including pesticides (Hodgson & Levi, 1992, Levi & Hodgson, 1991), are metabolized by many enzymes including: cytochrome P450s (P450); flavin-containing monooxygenases (FMO); prostaglandin synthetase; molybdenum hydroxylases; alcohol dehydrogenase; aldehyde dehydrogenase; esterases; and a variety of transferases, particularly the glutathione transferases. Of these P450 appears to be the most important, followed by the FMO. It should also be remembered that pesticides may serve not only as substrates for these enzymes but, particularly in the case of P450, may serve also as inhibitors and/or inducers. The toxicological implications of these multiple roles are important and are illustrated by our studies of methylenedioxyphenyl (MDP) compounds, of the herbicide synergist Tridiphane and the herbicide, dichlobenil, of metabolism in target tissues and portals of entry, and of insect resistance to insecticides.
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Induction of cytochrome P450 4A1 in mouse liver by the herbicide synergist Tridiphane
Pesticide Biochemistry and Physiology, 1992Co-Authors: Patricia E. Levi, Randy L. Rose, Nancy H. Adams, Ernest HodgsonAbstract:Abstract The herbicide synergist Tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2,-trichloroethyl) oxirane] was examined for its ability to induced cytochrome P450 in vivo. Male C57BL/6N mice were given Tridiphane, 250 mg/kg ip, for 3 days. Liver weight and P450 content were increased after Tridiphane treatment, and SDS-PAGE showed an increase in microsomal proteins in the 50–60 kDa range. No significant increases in enzymatic activities were observed with the substrates benzphetamine, p-nitroanisole, benzo[a]pyrene, or ethoxyresorufin. There was, however, a 10-fold elevation in microsomal hydroxylation of lauric acid, an activity specifically associated with induction of P450 4A1, Western blot analysis using an antibody specific for P450 4A1 showed a dramatic increase in P450 4A1.
Patricia E. Levi - One of the best experts on this subject based on the ideXlab platform.
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the role of oxidative enzymes in the metabolism and toxicity of pesticides
1995Co-Authors: Ernest Hodgson, Randy L. Rose, Nancy H. Adams, Nora J Deamer, Mary Beth Genter, Krishnappa Venkatesh, Patricia E. LeviAbstract:Xenobiotics, including pesticides (Hodgson & Levi, 1992, Levi & Hodgson, 1991), are metabolized by many enzymes including: cytochrome P450s (P450); flavin-containing monooxygenases (FMO); prostaglandin synthetase; molybdenum hydroxylases; alcohol dehydrogenase; aldehyde dehydrogenase; esterases; and a variety of transferases, particularly the glutathione transferases. Of these P450 appears to be the most important, followed by the FMO. It should also be remembered that pesticides may serve not only as substrates for these enzymes but, particularly in the case of P450, may serve also as inhibitors and/or inducers. The toxicological implications of these multiple roles are important and are illustrated by our studies of methylenedioxyphenyl (MDP) compounds, of the herbicide synergist Tridiphane and the herbicide, dichlobenil, of metabolism in target tissues and portals of entry, and of insect resistance to insecticides.
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Induction of cytochrome P450 4A1 in mouse liver by the herbicide synergist Tridiphane
Pesticide Biochemistry and Physiology, 1992Co-Authors: Patricia E. Levi, Randy L. Rose, Nancy H. Adams, Ernest HodgsonAbstract:Abstract The herbicide synergist Tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2,-trichloroethyl) oxirane] was examined for its ability to induced cytochrome P450 in vivo. Male C57BL/6N mice were given Tridiphane, 250 mg/kg ip, for 3 days. Liver weight and P450 content were increased after Tridiphane treatment, and SDS-PAGE showed an increase in microsomal proteins in the 50–60 kDa range. No significant increases in enzymatic activities were observed with the substrates benzphetamine, p-nitroanisole, benzo[a]pyrene, or ethoxyresorufin. There was, however, a 10-fold elevation in microsomal hydroxylation of lauric acid, an activity specifically associated with induction of P450 4A1, Western blot analysis using an antibody specific for P450 4A1 showed a dramatic increase in P450 4A1.
Randy L. Rose - One of the best experts on this subject based on the ideXlab platform.
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the role of oxidative enzymes in the metabolism and toxicity of pesticides
1995Co-Authors: Ernest Hodgson, Randy L. Rose, Nancy H. Adams, Nora J Deamer, Mary Beth Genter, Krishnappa Venkatesh, Patricia E. LeviAbstract:Xenobiotics, including pesticides (Hodgson & Levi, 1992, Levi & Hodgson, 1991), are metabolized by many enzymes including: cytochrome P450s (P450); flavin-containing monooxygenases (FMO); prostaglandin synthetase; molybdenum hydroxylases; alcohol dehydrogenase; aldehyde dehydrogenase; esterases; and a variety of transferases, particularly the glutathione transferases. Of these P450 appears to be the most important, followed by the FMO. It should also be remembered that pesticides may serve not only as substrates for these enzymes but, particularly in the case of P450, may serve also as inhibitors and/or inducers. The toxicological implications of these multiple roles are important and are illustrated by our studies of methylenedioxyphenyl (MDP) compounds, of the herbicide synergist Tridiphane and the herbicide, dichlobenil, of metabolism in target tissues and portals of entry, and of insect resistance to insecticides.
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Induction of cytochrome P450 4A1 in mouse liver by the herbicide synergist Tridiphane
Pesticide Biochemistry and Physiology, 1992Co-Authors: Patricia E. Levi, Randy L. Rose, Nancy H. Adams, Ernest HodgsonAbstract:Abstract The herbicide synergist Tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2,-trichloroethyl) oxirane] was examined for its ability to induced cytochrome P450 in vivo. Male C57BL/6N mice were given Tridiphane, 250 mg/kg ip, for 3 days. Liver weight and P450 content were increased after Tridiphane treatment, and SDS-PAGE showed an increase in microsomal proteins in the 50–60 kDa range. No significant increases in enzymatic activities were observed with the substrates benzphetamine, p-nitroanisole, benzo[a]pyrene, or ethoxyresorufin. There was, however, a 10-fold elevation in microsomal hydroxylation of lauric acid, an activity specifically associated with induction of P450 4A1, Western blot analysis using an antibody specific for P450 4A1 showed a dramatic increase in P450 4A1.
Nancy H. Adams - One of the best experts on this subject based on the ideXlab platform.
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the role of oxidative enzymes in the metabolism and toxicity of pesticides
1995Co-Authors: Ernest Hodgson, Randy L. Rose, Nancy H. Adams, Nora J Deamer, Mary Beth Genter, Krishnappa Venkatesh, Patricia E. LeviAbstract:Xenobiotics, including pesticides (Hodgson & Levi, 1992, Levi & Hodgson, 1991), are metabolized by many enzymes including: cytochrome P450s (P450); flavin-containing monooxygenases (FMO); prostaglandin synthetase; molybdenum hydroxylases; alcohol dehydrogenase; aldehyde dehydrogenase; esterases; and a variety of transferases, particularly the glutathione transferases. Of these P450 appears to be the most important, followed by the FMO. It should also be remembered that pesticides may serve not only as substrates for these enzymes but, particularly in the case of P450, may serve also as inhibitors and/or inducers. The toxicological implications of these multiple roles are important and are illustrated by our studies of methylenedioxyphenyl (MDP) compounds, of the herbicide synergist Tridiphane and the herbicide, dichlobenil, of metabolism in target tissues and portals of entry, and of insect resistance to insecticides.
-
Induction of cytochrome P450 4A1 in mouse liver by the herbicide synergist Tridiphane
Pesticide Biochemistry and Physiology, 1992Co-Authors: Patricia E. Levi, Randy L. Rose, Nancy H. Adams, Ernest HodgsonAbstract:Abstract The herbicide synergist Tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2,-trichloroethyl) oxirane] was examined for its ability to induced cytochrome P450 in vivo. Male C57BL/6N mice were given Tridiphane, 250 mg/kg ip, for 3 days. Liver weight and P450 content were increased after Tridiphane treatment, and SDS-PAGE showed an increase in microsomal proteins in the 50–60 kDa range. No significant increases in enzymatic activities were observed with the substrates benzphetamine, p-nitroanisole, benzo[a]pyrene, or ethoxyresorufin. There was, however, a 10-fold elevation in microsomal hydroxylation of lauric acid, an activity specifically associated with induction of P450 4A1, Western blot analysis using an antibody specific for P450 4A1 showed a dramatic increase in P450 4A1.
Ko Wakabayashi - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of Very-Long-Chain Fatty Acid Formation by Indanofan, 2-[2-(3-Chlorophenyl)oxiran-2-ylmethyl]-2-ethylindan-1,3-dione, and Its Relatives
2002Co-Authors: Hideomi Takahashi, Jochen Schmalfuß, Aiko Ohki, Akemi Hosokawa, Akira Tanaka, Yukiharu Sato, Bernd Matthes, Peter Böger, Ko WakabayashiAbstract:Rice Herbicides, Very-Long-Chain Fatty Acids, Tridiphane Indanofan and its analogs inhibited the elongation of stearoyl-or arachidoyl-CoA by [2-14 C]-malonyl-CoA in leek microsomes from Allium porrum. Although the precise mode of interaction of indanofan at the molecular level is not completely clarified by the present study, it is concluded that indanofan and analogs act as inhibitor of the elongase enzyme involved in de novo biosynthesis of fatty acids with an alkyl chain longer than C 18 , called very-long-chain fatty acids (VLCFAs). For a strong inhibition of VLCFA formation chloro substituents at the benzene ring and the oxirane group were necessary. Furthermore, the greenhouse test showed strong activity for indanofan and its analogs, and the scores coincided with cell-free elongation inhibition. The cell-free assay, however, failed to indicate any activity for an analog having a methylene instead of the oxirane group, while both Digitaria ciliaris and Echinochloa oryzicola were killed with 1 kg a.i./ha. This finding cannot be discussed because the applied use rate of 1 kg a.i./ha is too high to allow for a score differentiation. For high concentrations of this compound additional unknown inhibitory effects may be involved besides fatty acid elongation
