X-RADIATION INDUCES 8-HYDROXY-2'-DEOXYGUANOSINE FORMATION IN-VIVO IN RAT MAMMARY-GLAND DNA

Ionizing radiation is a carcinogen that induces oxidative DNA damage. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) is a relatively abundant, mutagen ic lesion that is widely regarded as a reliable index of oxidative DNA damage. The purpose of this study was to examine the effects of X-rad iation on levels of 8-OHdG in the context of an experimental model for breast cancer in which chronic radiation exposure has been shown to b e carcinogenic in Sprague-Dawley rats. A secondary objective of this s tudy was to determine if the use of phenol during DNA isolation affect ed the concentration of 8-OHdG subsequently measured. Our results indi cate that a profoundly carcinogenic dose of radiation induced a small but significant increase in 8-OHdG concentration in mammary gland DNA, and that the use of a phenol-based versus a salt-based method of DNA isolation had no significant impact on the levels of 8-OHdG detected i n either control or irradiated tissue.