In vivo radioprotection by 5-androstenediol: stimulation of the innate immune system.

Abstract Whitnall, M. H., Inal, C. E., Jackson, W. E., III, Miner, V. L., Villa, V. and Seed, T. M. In Vivo Radioprotection by 5-Androstenediol: Stimulation of the Innate Immune System. Radiat. Res. 156, 283–293 (2001). We showed previously that 5-androstenediol stimulates myelopoiesis, increases the numbers of circulating neutrophils and platelets, and enhances resistance to infection in γ-irradiated mice. We have extended those studies to include monocytes, natural killer (NK) cells, eosinophils and basophils, and we have measured the activation marker CD11b using flow cytometry. Androstenediol (160 mg/kg) was administered subcutaneously to female B6D2F1 mice 24 h before whole-body γ irradiation. Androstenediol treatments increased the blood levels of neutrophils, monocytes and NK cells in unirradiated animals; decreased the numbers of circulating eosinophils; and ameliorated radiation-induced decreases in neutrophils, monocytes, NK cells, erythrocytes and platelets. The androstenediol treatments had no...