8-HYDROXYDEOXYGUANOSINE IN DNA FROM TPA-STIMULATED HUMAN GRANULOCYTES

8-Hydroxydeoxyguanosine (8-OHdG) is now widely used as a sensitive mar ker of oxidative damage to DNA. When human granulocytes are stimulated with TPA, they release a large quantity of reactive oxygen species (s uperoxide, hydrogen peroxide) which might be expected to generate hydr oxyl radicals (OH.) which in turn could produce 8-OHdG in the DNA. The re had been considerable debate as to whether OH is detectable in stim ulated granulocytes; most workers now agree that none can be detected, unless exogenous iron is added. An earlier report had described that 8-OHdG (a marker of OH.) was increased in the DNA of TPA-stimulated, c ompared to control, granulocytes. We have repeated this experiment and have been unable to reproduce this finding. We conclude that the amou nt of 8-OHdG produced in the DNA of TPA-stimulated human ganulocytes i s indistinguishable from that seen in control (unstimulated) cells (le ss than one 8-OHdG/10(5) dG).