Forssman's antibody was obtained from rabbits by injecting 10 percent saline emulsion of guinea pig kidney seven times every four day.
The minimum lethal dose of Forssman's antibody was administered into guinea pigs after the whole body X-irradiation. The effect of the irradiation on the lethality, the time to the death, the reduction rate of the complement, weight of the lung and clinical signs were investigated. The results were as follows: 1) By 200r irradiation, the reverse-anaphylaxis of guinea pigs by Forssman's antibody was restrained, and the lethal minimum dose was highest around the 14th day, and gradually returned to normal around the 21st day. 2) By 200r iradiation, the period of incubation until the typical shock of reverseanaphylaxis and the duration until the death by shock were prolonged. 3) By 200r irradiation, the lung-weight showed a tendency to be lightened in comparison with the control group. 4) By X-irradiation below 100r, no typical view was found, but it seemed to have the same tendency with the 200r exposure as a whole.