Determination of 8-oxoguanine and 8-hydroxy-2′-deoxyguanosine in the rat cerebral cortex using microdialysis sampling and capillary electrophoresis with electrochemical detection

Abstract

A rapid and sensitive method to determine 8-oxoguanine (8oxoG) and 8-hydroxydeoxyguanosine (8OHdG), biomarkers for oxidative DNA damage, in cerebral cortex microdialysate samples using capillary electrophoresis with electrochemical detection was developed. Samples were concentrated on-column using pH-mediated stacking for anions. On-column anodic detection was performed with a carbon fiber working electrode and laser-etched decoupler. The method is linear over the expected extracellular concentration range for 8oxoG and 8-OHdG during induced ischemia-reperfusion, with RSD values ≤ 5 % and limits of detection of 0.5 nM for both analytes. Basal concentrations of 8oxoG in rat cerebral cortex microdialysate were determined to be 3.2 ± 0.6 nM. Actual 8oxoG concentration in the brain was estimated to be 5.5 ± 1.3 nM based on probe calibration by in vivo delivery. 8OHdG was not detected under basal conditions in the rat cerebral cortex extracellular fluid. These results were confirmed by LC with tandem mass spectrometry.

Combination of resveratrol and fluoxetine in an acute model of depression in mice: Prevention of oxidative DNA fragmentation and monoamines degradation

“…8-OHDG content is considered a sensitive biomarker of the oxidative DNA damage and repair (Kouda et al, 2001); there are several hundred reports linking increased concentrations of 8-OHDG to increased oxidative stress or disease states (Arnett et al, 2005). Nitric oxide (NO) is another important and versatile molecule in neurogenesis and accumulating evidence supports the hypothesis that it plays a critical role in neurodegenerative disorders (Bogdan, 2001).…”

The study of DNA adduct 8-hydroxy-2′deoxyguanosine (8-OHdG) formation of butylated hydroxyanisole (BHA) and its metabolite ter-butyl hydroquinone (TBHQ) through in vitro reaction with Calf Thymus DNA and 2′deoxyguanosine

“…Meanwhile, incubation with TBHQ was conducted in various concentrations, 20, 40, 60, 80, 100, 120, 160, 200, 300, 400, and 500 ppm in 50 mM Tris HCl solvent, pH 7.4; the reaction mixture was incubated for 1 hour at temperature 37°C. The formation of DNA adduct was analyzed by using HPLC, and 8 -OHDG was measured towards 2' deoxyguanosine (table 3 [12]). …”

Analytical Considerations for Microdialysis Sampling

“…The cutaneous nicotine concentration was Figure 11 Identifi cation of 8 -oxyguanine (8oxoG) and 8 -hydroxy -2 ' -deoxyguanosine (8OHdG) in rat brain dialysate by capillary electrophoresis with electrochemical detection. (From [117] .) Figure 13 ).…”

“…There have been several applications of online MD -LC systems reported over the past decade by the Tsai group and others for the in vivo monitoring of drugs [112 -116] , neurotransmitters, neuropeptides, and other important biomolecules, including reactive oxygen species [117,118] . Applications included primarily pharmacokinetic, metabolism, and neurochemical studies.…”