Ortho-toluidine blood protein adducts: HPLC analysis with fluorescence detection after a single dose in the adult male rat.
Cheever KL; DeBord DG; Swearengin TF; Booth-Jones AD
Fundam Appl Toxicol 1992 May; 18(4):522-531
High performance liquid chromatography (HPLC) and fluorescence detection were used to quantify ortho-toluidine (95534) (OT) blood protein adducts after single dose administration to adult male Sprague-Dawley-rats. The animals received labeled OT concentrations of 10, 20, 40, 50, and 100mg/ml corn-oil by gavage or intraperitoneal injection. Blood collected from treated animals was processed for isolation of hemoglobin and albumin. Mild alkaline hydrolysis of the labeled OT adducted proteins followed by extraction with ethyl-acetate yielded 63% of bound radioactivity. A single radiolabeled peak obtained on HPLC was identified as OT by gas chromatography/mass spectrometry. Fluorescence detection was used in subsequent experiments. After administration of a single 50mg/kg dose of OT, the adduct accumulated more in association with Hb than with albumin. A linear relationship was evident between dose and 4 hour adduct formation. The highest adduct levels were detected in animals dosed at 100mg/kg body weight. Serial termination of rats over 28 days revealed that the adduct half life is 11 days. The authors conclude that the quantification of OT-Hb adducts may provide a valuable index of cumulative long term exposure to this carcinogen.
NIOSH-Author; Biokinetics; Carcinogens; Chemical-kinetics; Laboratory-animals; Metabolism; Organic-compounds; Toxicology; Chromatographic-analysis
Fundamental and Applied Toxicology