Enhanced peroxisomal beta-oxidation of fatty acids and glutathione metabolism in rats exposed to phenoxyacetic acids.
Peroxisomal beta-oxidation of fatty acids and the activities of glutathione-metabolizing enzymes in rat liver were measured after administration of 2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2-methylphenoxyacetic acid (MCPA), clofibrate [ethyl], 2-(p-chlorophenoxy)-2-methylpropionate], glyphosate (N-phosphonomethyl glycine, a herbicide not structurally related to phenoxy acids) or saline for 14 days. beta-Oxidation increased by 6-fold in the group given clofibrate, 3-fold in the 2,4-D-treated group, and 2-fold in the MCPA-treated group over the level in the controls (saline-treated). Glyphosate did not increase beta-oxidation. No significant change in reduced glutathione content from that in controls was found in any of the treated groups. Glutathione reductase activity increased by about 40% after administration of either 2,4-D or MCPA, and glutathione peroxidase activity increased by 30% in animals given MCPA. A slight decrease in glutathione S-transferase activity was found in the group treated with clofibrate. The marked increases in peroxisomal beta-oxidation of fatty acids were accompanied by only minor changes in the activities of enzymes involved in glutathione-dependent inactivation of organic hydroperoxides and other oxygen-centred reactive agents.
D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity; D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000633:toxicity; D000818:Animals; D002994:Clofibrate / Q000633:toxicity; D005227:Fatty Acids / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D005998:Glycine / Q000031:analogs & derivatives / Q000633:toxicity; D006016:Glycolates / Q000633:toxicity*; D006540:Herbicides / Q000633:toxicity; D008099:Liver / Q000648:ultrastructure*; D008297:Male; D008830:Microbodies / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D010642:Phenoxyacetates / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D000097797:Glyphosate
D015084:2,4-Dichlorophenoxyacetic Acid; D008456:2-Methyl-4-chlorophenoxyacetic Acid; D002994:Clofibrate; D005227:Fatty Acids; D005978:Glutathione; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005998:Glycine; D006016:Glycolates; D006540:Herbicides; D010642:Phenoxyacetates; D000097797:Glyphosate