Effect of total body X-irradiation on the hexobarbital oxidase activity in the rat liver

It is established that the hexobarbital oxidase activity of 12,000 g rat liver supernatant does not change when examined at the 2nd h after whole body irradiation (700 R) but increases at longer postexposure periods (72 hours). Intraperitoneal injection of phenobarbital in daily doses of 80 mg/kg body wt for three days increases the hexobarbital oxidase activity of non-irradiated rats, the effect being much stronger in phenobarbital-treated rats at the 2nd h of postirradiation. The possible mechanisms of these effects are discussed, as well as their correlation with the increased lipid peroxidation and their significance for the radiation effect on the drug action.