Biologic interaction of gamma radiation with phenylbutazone, phenytoin, or hydralazine

Combination of repeated administration of phenylbutazone (7 mg/kg for two weeks) or phenytoin (20 mg/kg for four weeks) and acute exposure to gamma radiation (696 REM) induced increased lethality in mice much greater than that observed fro use of either drug or radiation alone. Lethality in chronic hydralazine (10 mg/kg for four weeks) treated mice subjected also to gamma radiation was not different than that observed after either drug or radiation alone. Decrease in liver glutathione was observed in mice receiving combined drug-radiation treatment as also were leucocyte counts, but neither of these parameters supported as assumption of site of common lethal mechanism.