Synergistic Action of Cortisone and Total-Body Irradiation in Mice

Abstract

Inbred male white mice, 25 gm. body wt., received in 1 exposure either the approx. LD50/14 days or a sublethal X-ray dose (220 kV, 0.5 mm. Cu filter, HVL. 1.0 mm. Cu). Cortisone in doses of 1 mg. or 3 mg. was admd. subcut. once or twice prior to or after irradiation. Cortisone enhanced the lethal effect of total body irradiation irrespective ot the time of admn., (100% mortality of the animals exposed to the LD50). Mortality rate was also accelerated; this was more pronounced when cortisone was given after irradiation. Pretreatment with cortisone also caused a high mortality in mice exposed to the sublethal X-ray dose. Attempts to modify the cortisone-induced enhancement of total-body X-ray mortality by either glutathione or cysteine prior to irradiation failed completely.