title: Biomonitoring of benzene exposure by trace analyses of phenylguanine.
abstract: From preliminary experiments it was known that radiolabelled benzene and some of its metabolites during its metabolic activation process produce different in vitro DNA-phenyladducts in mitoplasts. As we reported previously at least one of these adducts, N-7-phenylguanine, is excreted in the urine of rats in measurable amounts, probably through an excision-repair mechanism after an inhalation experiment. Now we found, after i.p. application of benzene in the urine of rats, a compound separated by cation-exchange chromatography that behaves like a synthesized N-7-phenylguanine reference substance with respect to its retention index and the UV-absorption. This finding could be confirmed by HPLC-measurements with reversed-phase carrier materials. Silylation and gas chromatographic/mass spectrometric (GC/MS) separation of the fraction, which contains the phenylguanine, revealed that these fractions contain further phenyl adducts. Furthermore we studied the time-dependent excretion of the DNA-base adduct. Surprisingly the excretion dropped to zero on the fourth day and showed a new increase thereafter.
authors.affiliation: Institute of Hygiene and Occupational Medicine, University of Essen, Federal Republic of Germany.
authors.forename: K
authors.initials: K
authors.lastname: Norpoth
authors.forename: W
authors.initials: W
authors.lastname: Stücker
authors.forename: E
authors.initials: E
authors.lastname: Krewet
authors.forename: G
authors.initials: G
authors.lastname: Müller
mesh_terms: D000818:Animals; D001554:Benzene / Q000378:metabolism*; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D004781:Environmental Exposure; D008401:Gas Chromatography-Mass Spectrometry; D006147:Guanine / Q000031:analogs & derivatives* / Q000652:urine; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: C056235:N(7)-phenylguanine; D006147:Guanine; D001554:Benzene