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, mutageniclesion that is widely regarded as a reliable index of oxidative DNA damage.The purpose of this study was to examine the effects of X- radiation onlevels of 8-OHdG in the context of an experimental model for breast cancerin which chronic radiation exposure has been shown to be carcinogenic inSprague-Dawley rats. A secondary objective of this study was to determineif the use of phenol during DNA isolation affected the concentration of8-OHdG subsequently measured. Our results indicate that a profoundlycarcinogenic dose of radiation induced a small but significant increase in8-OHdG concentration in mammary gland DNA, and that the use of aphenol-based versus a salt-based method of DNA isolation had no significantimpact on the levels of 8-OHdG detected in either control or irradiatedtissue.