title: [Chronobiological evaluation of effects biomarkers and sampling].
abstract: Occupational exposure to oxidants is often associated with an increase in the levels of oxidative DNA damage in urine. Besides 8-hydroxy-2'-deoxyguanosine (8-oxo-dG), other products of position-8 guanine oxidation have been identified in urine, including 8-hydroxy-guanine (8-oxo-G) and 8-hydroxyguanosine (8-oxy-Guo). The aim of the present study was the characterization of these effect biomarkers in terms of inter- and intra-individuals varaibility, as well as in terms of their excretion profile during a 24 h-period. Urine samples were collected from 11 volunteers (6 samples/day). Urine concentrations of 8-oxo-G, 8-oxo-Guo, and 8-oxo-dG were determined by liquid chromatography-tandem mass spectrometry. The inter-individual variability, expressed as variation coefficient, was 85-150% for 8-oxo-G, 20-45% for 8-oxo-Guo, and 30-45% for 8-oxo-dG. The statistical anaysis for repeated measurements showed that none of the biomarkers was affected by significant variation during the day (one-way ANOVA, p < 0.05), thus excluding the existence of a circadian rhythm. We conclude that the sampling time is not critical for the assessment of oxidative DNA damage in urine.
authors.affiliation: Università di Parma, Dipartimento di Clinica Medica, Nefrologia e Scienze della Prevenzione, Parma.
authors.forename: R
authors.initials: R
authors.lastname: Andreoli
authors.forename: P
authors.initials: P
authors.lastname: Manini
authors.forename: R
authors.initials: R
authors.lastname: Alinovi
authors.forename: M
authors.initials: M
authors.lastname: Goldoni
authors.forename: G
authors.initials: G
authors.lastname: De Palma
authors.forename: A
authors.initials: A
authors.lastname: Mutti
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000652:urine*; D002853:Chromatography, Liquid; D002909:Chronobiology Phenomena; D002940:Circadian Rhythm; D004249:DNA Damage; D005260:Female; D006147:Guanine / Q000031:analogs & derivatives* / Q000652:urine; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D013997:Time Factors
chemical_list: D015415:Biomarkers; D007202:Indicators and Reagents; C024829:8-hydroxyguanine; D006147:Guanine