Synergism in the action of gamma radiation and cardiac glycosides

Synergism of gamma radiation with 137Cs and cardiac glycosides was investigated in experiments on mice and transplantable Raji tumor cells. A single ip administration of these drugs at nontoxic concentrations 30-60 min. after irradiation at the LD30/30 resulted in the survival of 13-20% of animals and the reduction of the mean survival time up to 8.4-12.5 days versus 22.3 days in the control group. Synergism was slightly decreased at administration of glycosides 24 h after irradiation. Glycosides introduced in the irradiated (at a dose of 1-2.5 Gy) human lymphoblastic line caused sharp suppression of lymphoma growth and cellular lysis in experiments in vitro. One hundred per cent death of cells was noted after the use of the drugs at mean toxic concentrations.