Chemical modification of adrenal response to external whole body irradiation in mice.

Adult Swiss albino mice were exposed to whole body gamma irradiation with 1.5, 3.0, 6.0 and 9.0 Gy in the presence or absence of the protective drugs MPG and WR-2721. The changes in the total cell population, pyknotic nuclei and necrotic cells, and binucleate cells were observed at various post-irradiation times. The degree of damage increased with the radiation dose. The number of total cells decreased with a corresponding increase in pyknotic nuclei, necrotic cells and binucleate cells. Both drugs provided protection against radiation injury, and reduced early post-irradiation cell damage and enhanced recovery after sublethal exposures. After higher doses, especially after lethal doses, the drugs became less effective in protecting the tissue.