title: Noninvasive markers of oxidative DNA stress, RNA degradation and protein degradation are differentially correlated with resting metabolic rate and energy intake in children and adolescents.
abstract: Urinary excreted RNA and DNA catabolites are used as noninvasive markers for metabolic processes: 8-oxo-2'-deoxyguanosine (8-oxodG) potentially represents oxidative stress to DNA/deoxyribonucleotidetriphosphate pool, modified ribonucleoside pseudouridine (psi) originating mainly from degraded rRNA and tRNA reflects RNA turnover. Modified amino acid gamma-carboxyglutamic acid (Gla) stems from degraded proteins reflecting turnover of proteins. Aim of the present study was to investigate (44 healthy males, 3-18 y) how excretion rates of 8-oxodG, psi, and Gla are related to resting metabolic rate and energy intake. Excretion rates of 8-oxodG (pmol/kg/d), psi (micromol/kg/d), and Gla (micromol/kg/d) were significantly correlated with resting metabolic rate (kJ/kg/d): r = 0.108 (p = 0.029), 0.691 and 0.552 (p < 0.0001), respectively. Excretion rates of 8-oxodG, psi, and Gla were also significantly correlated with energy intake (kJ/kg/d): r = 0.108 (p = 0.036), 0.602 and 0.462 (p < 0.0001). 8-oxodG and Gla excretion was significantly correlated with psi excretion: r = 0.174 (p = 0.005) and 0.709 (p < 0.0001). These results indicate close relationships between whole-body RNA and protein degradation and metabolic rate. The relationship between 8-oxodG excretion and metabolic rate, however, is less strong suggesting that factors other than metabolic rate considerably affect the oxidative stress to DNA.
authors.affiliation: Neonatology, University Children's Hospital, 17487 Greifswald, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Topp
authors.forename: Gerhard
authors.initials: G
authors.lastname: Fusch
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schöch
authors.forename: Christoph
authors.initials: C
authors.lastname: Fusch
mesh_terms: D015055:1-Carboxyglutamic Acid / Q000652:urine*; D000080242:8-Hydroxy-2'-Deoxyguanosine; D000293:Adolescent; D001481:Basal Metabolism / Q000502:physiology*; D015415:Biomarkers / Q000652:urine; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D004249:DNA Damage / Q000502:physiology; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000652:urine; D002149:Energy Intake / Q000502:physiology*; D006801:Humans; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D011506:Proteins / Q000378:metabolism; D011560:Pseudouridine / Q000652:urine*; D020871:RNA Stability / Q000502:physiology
chemical_list: D015415:Biomarkers; D011506:Proteins; D011560:Pseudouridine; D015055:1-Carboxyglutamic Acid; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine