Effect of x-ray radiation on hypersensitiveness

Abstract

1. 1. A series of 40 adult rabbits were studied to reveal the effect of x-ray radiation on various phenomena of hypersensitiveness, namely, diffuse vascular disease and carditis, Arthus phenomenon, Schultz-Dale reactions, and precipitin formation. 2. 2. Twenty-eight animals received 600 r and 800 r of x-ray radiation 24 to 72 hours before the sensitizing dose of horse serum. Four received no horse serum but received the x-ray radiation. Eight other animals were used as controls and received parallel doses of horse serum without x-ray radiation. 3. 3. Microscopic sections of the irradiated and later sensitized animals showed a marked reduction in the number and intensity of vascular lesions and carditis, indicating the inhibitory action of x-ray on the development of these lesions. The Arthus phenomenon was consistently negative in the irradiated animals as compared with the controls. The Schultz-Dale reactions showed inconclusive and inconsistent results. The precipitin reactions showed depressed titers in the irradiated animals as compared to the controls. 4. 4. Complete blood counts revealed marked leukopenia and depression of the lymphocyte counts on the irradiated animals as compared to the normal control animals. 5. 5. X-ray radiation of normal nonsensitized animals showed no lesions of diffuse vascular disease or carditis.