title: Prostaglandin synthase and horseradish peroxidase catalyzed DNA-binding of p-phenetidine.
abstract: The prostaglandin synthase and horseradish peroxidase catalyzed binding of p-phenetidine to DNA was investigated. The addition of arachidonic acid to an incubation containing ram seminal vesicle microsomes, [14C]p-phenetidine and DNA resulted in a rapid incorporation of radioactivity into DNA. This was inhibited by greater than 75% by indomethacin (0.1 mM) or butylated hydroxyanisole (0.5 mM). Hydrogen peroxide was as efficient as arachidonic acid in mediating the activation of p-phenetidine thus implicating the involvement of the hydroperoxidase activity of prostaglandin synthase in this reaction. Horseradish peroxidase and hydrogen peroxide also catalyzed the activation of p-phenetidine to DNA-binding metabolites. Reduced glutathione (GSH) stimulated the binding of p-phenetidine to DNA by greater than 3-fold in both the prostaglandin synthase and the horseradish peroxidase system, whereas cysteine and N-acetylcysteine reduced the DNA-binding in the prostaglandin synthase system by up to 62% under the conditions used. Furthermore, water-soluble metabolites formed in the presence of GSH also bound to DNA. Seventy-two hour dialysis of DNA samples from incubations with GSH present reduced the amount of bound material by 75%. In contrast, the radioactivity which associated with DNA in the absence of GSH was not decreased by dialysis.
mesh_terms: D000627:Aminophenols / Q000378:metabolism*; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids; D002083:Butylated Hydroxyanisole / Q000494:pharmacology; D002417:Cattle; D004247:DNA / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006861:Hydrogen Peroxide; D007213:Indomethacin / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D010544:Peroxidases / Q000378:metabolism*; D010628:Phenetidine / Q000378:metabolism*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D012669:Seminal Vesicles / Q000201:enzymology; D012756:Sheep; D013950:Thymus Gland
chemical_list: D000627:Aminophenols; D001095:Arachidonic Acids; D010628:Phenetidine; D002083:Butylated Hydroxyanisole; D016718:Arachidonic Acid; D004247:DNA; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D010544:Peroxidases; D011451:Prostaglandin-Endoperoxide Synthases; D007213:Indomethacin