Eur J Appl Physiol (2010) 108:213 DOI 10.1007/s00421-009-1196-1 123 L E T T E R T O T H E E D I T O R Glutathione measurements in blood samples are inXuenced by oxygen saturation Dieter Böning Accepted: 31 August 2009 / Published online: 17 September 2009 © Springer-Verlag 2009 Dear Editor Heinicke et al. (2009) describe a temporary increase in erythrocyte reduced glutathione concentration by 12–20% in venous blood samples after ascent to 2,800 m above the sea level. I wonder why the authors do not present also oxi- dized glutathione which yield additional insight since their method (Tietze 1969) allows determination of both forms. Also, they have diYculties to interpret their result as improved antioxidant defense, since the values return to control values within 2 weeks at altitude. The cause is prob- ably that the changes are at least partly measuring artifacts: hemoglobin that binds glutathione much better in oxygen- ated than deoxygenated form (Craescu et al. 1986) is precipitated before analysis; thus, an unknown amount of glutathione disappears from the supernatant. We have shown that after in vitro equilibration with diVerent oxygen pressures measured total glutathione concentrations decrease by 20% between 0 and 100% O2 saturation (Hütler et al. 2000); the decrease in reduced glutathione is even larger (30%), whereas the small fraction of oxidized gluta- thione increases Wvefold. As venous oxygen content falls markedly during ascent and later rises again, this might be the cause of glutathione concentration changes. The possible error is easy to correct if the authors have measured venous O2 saturations. In addition, the change in concentrations of free reduced and oxidized glutathione within the red cell after a decrease in average O2 saturation should inXuence synthesis and trans-membrane transport of this substance. Therefore, all investigations without considering these eVects do not allow clear conclusions about antioxidant defense by glutathione in blood. References Craescu CT, Poyart C, SchaeVer C, Garel MC, Kister J, Beuzard Y (1986) Covalent binding of glutathione to hemoglobin. II. Func- tional consequences and structural changes reXected in NMR spectra. J Biol Chem 261(31):14710–14716 Heinicke I, Boehler A, Rechsteiner T, Bogdanova A, Jelkmann W, Hofer M, Rawlings P, Araneda OF, Behn C, Gassmann M, Heinicke K (2009) Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate. Eur J Appl Physiol 106:599–604 Hütler M, Pollmann C, Beneke R, Leithauser R, Böning D (2000) Mea- surable amount of glutathione in blood is inXuenced by oxygen saturation of hemoglobin. Clin Chim Acta 301:213–217 Tietze F (1969) Enzymic method for quantitative determination of nanogram amounts of total and oxidized glutathione. Anal Biochem 27:502–522 D. Böning (&) Sportmedizin Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Arnimallee 22, 14195 Berlin, Germany e-mail: dieter.boening@charite.de Glutathione measurements in blood samples are inXuenced by oxygen saturation Dear Editor References << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /None /Binding /Left /CalGrayProfile (None) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (ISO Coated v2 300% \050ECI\051) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Error /CompatibilityLevel 1.3 /CompressObjects /Off /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJDFFile false /CreateJobTicket false /DefaultRenderingIntent /Perceptual /DetectBlends true /ColorConversionStrategy /sRGB /DoThumbnails true /EmbedAllFonts true /EmbedJobOptions true /DSCReportingLevel 0 /SyntheticBoldness 1.00 /EmitDSCWarnings false /EndPage -1 /ImageMemory 524288 /LockDistillerParams true /MaxSubsetPct 100 /Optimize true /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveEPSInfo true /PreserveHalftoneInfo false /PreserveOPIComments false /PreserveOverprintSettings true /StartPage 1 /SubsetFonts false /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 150 /ColorImageDepth -1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.76 /HSamples [2 1 1 2] /VSamples [2 1 1 2] >> /ColorImageDict << /QFactor 0.76 /HSamples [2 1 1 2] /VSamples [2 1 1 2] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 150 /GrayImageDepth -1 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.76 /HSamples [2 1 1 2] /VSamples [2 1 1 2] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 600 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile (None) /PDFXOutputCondition () /PDFXRegistryName (http://www.color.org?) /PDFXTrapped /False /Description << /DEU /ENU >> >> setdistillerparams << /HWResolution [2400 2400] /PageSize [5952.756 8418.897] >> setpagedevice