DNA adduct formation in leukocytes and tissues from F344 rats and B6C3F₁ mice administered acrylamide or glycidamide. Free

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Acrylamide, a water-soluble α,β-unsaturated amide, is an important industrial chemical used in the production of polyacrylamides. Acrylamide is also utilized in biochemical applications and is a component of cigarette smoke. More recently, acrylamide has been detected in baked and fried starchy foods, including french fries, potato chips, and bread, with total daily dietary exposures estimated to be in the range of 1 μg/kg body weight. Acrylamide is a germ cell mutagen in male rodents and it induces tumors in experimental animals when administered topically or orally. Although acrylamide can undergo Michael-type addition reactions with nucleophilic centers in macromolecules, metabolic oxidation by CYP 2E1 to the epoxide glycidamide results in the formation of a more potent electrophile. In this study, we have determined the extent of glycidamide-DNA adduct formation in leukocytes and tissues from F344 rats and B6C3F₁ mice administered acrylamide and glycidamide. Liquid chromatography coupled with electrospray tandem mass spectrometry (LC-ES/MS/MS) was used to quantify N7-(2-carbamoyl-2-hydroxyethyl)guanine (N7-Gly-Gua) and N3-(2-carbamoyl-2-hydroxyethyl)adenine (N3-Gly-Ade). Adult F344 rats and B6C3F₁ mice were administered a single intraperitoneal dose of 50 mg/kg acrylamide or glycidamide. Six hours after treatment, the rodents were euthanized, tissues and blood were collected, and DNA was subsequently isolated. After neutral thermal hydrolysis, the released N7-Gly-Gua and N3-Gly-Ade DNA adducts were quantified by LC-ES/MS/MS using isotopically labeled internal standards. Serum concentrations of acrylamide and glycidamide were also measured by LC-ES/MS/MS using isotopically labeled internal standards. N7-Gly-Gua adduct levels were determined to be 15-70 adducts in 10⁶ nucleotides in leukocytes from rats and 10-20 adducts in 10⁶ nucleotides in tissues from mice; N3-Gly-Ade adducts were approximately 90-fold lower. These data are consistent with comparable levels of DNA damage from glycidamide occurring in both rodent species after acrylamide treatment and suggest that acrylamide-mediated DNA damage in peripheral blood leukocytes can predict DNA damage in human tissues for future exposure/risk assessments. (Supported by an Interagency Agreement between the NCTR/FDA and NIEHS/NTP)