title: Correlation between concentrations of 8-oxo-7,8-dihydro-2'-deoxyguanosine in urine, plasma and saliva measured by on-line solid-phase extraction LC-MS/MS.
abstract: BACKGROUND
  8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) is the most frequently measured biomarker of oxidative stress. Chromatographic-based methods for 8-oxodGuo in urine are well established; however, the 8-oxodGuo measurement in plasma and saliva has been problematic.
  
  
  METHODS
  We firstly and successfully applied an on-line solid-phase extraction (SPE) LC-MS/MS following manual SPE pretreatment to quantify the 8-oxodGuo both in plasma and saliva. Urine, plasma and saliva specimens were simultaneously collected from 50 healthy adults and measured for 8-oxodGuo.
  
  
  RESULTS
  Mean baseline levels of 8-oxodGuo in plasma and saliva were 21.7+/-9.2 and 5.1+/-2.6pg/ml, respectively, being far lower than that in urine (6.2+/-4.8ng/ml). The 8-oxodGuo levels obtained in this study for plasma and saliva were, however, up to several hundred times lower than those reported by commercial ELISA kit in the literature. Furthermore, the 8-oxodGuo levels in plasma and saliva were significantly correlated with the 8-oxodGuo levels in urine (Spearman correlation coefficients, r=0.33, P=0.02 for plasma and r=0.56, P=0.0015 for saliva). 8-OxodGuo in plasma was also correlated with the 8-oxodGuo in saliva (r=0.52, P=0.0041).
  
  
  CONCLUSIONS
  Significantly correlations were observed between plasma, saliva and urine, giving the possibility of using other body fluids in addition to urine for assessing whole body oxidative stress.
authors.affiliation: Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan. windyhu@csmu.edu.tw
authors.forename: Chiung-Wen
authors.initials: CW
authors.lastname: Hu
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Huang
authors.forename: Yi-Jie
authors.initials: YJ
authors.lastname: Li
authors.forename: Mu-Rong
authors.initials: MR
authors.lastname: Chao
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000293:Adolescent; D000328:Adult; D002853:Chromatography, Liquid; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000652:urine; D006801:Humans; D012463:Saliva / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine