Modification of Early Radiation Death in Guinea Pigs

¹ From the Radiation Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland

A series of depressant and anticonvulsant drugs has been used in an attempt to modify the ‘early’ or ‘central nervous system’ death in guinea pigs. Pentobarbital given in anesthetic doses prior to irradiation dramatically alters the course of injury induced by whole body doses of 6000 r or more. Survival time is sharply increased and all signs of convulsions and hyperexcitability are suppressed. Phenobarbital and paraldehyde show similar actions, but the margin of safe dosage is smaller than with pentobarbital. The action of pentobarbital appears to be a true radiation protection. Other drugs, such as diphenyl hydantoinate suppress convulsive activity and lengthen survival time slightly. This is probably due to a sparing action from the intense muscular activity associated with the convulsions. None of the drugs tested showed an effect when given after irradiation.