Radioprotection of pronormoblasts and normoblasts by WR-2721.

S-2 (3-aminopropylamino) ethyl phosphorothioic acid (WR-2721) has been investigated for its ability to protect pronormoblasts and normoblasts against radiation damage. Male Swiss albino mice were exposed to three different doses (2.5, 5 and 10 Gy) of gamma radiation from a 60Co source with or without the drug (at a dose of 300 mg/kg body weight). They were sacrificed at various intervals from twelve hours to 28 days and bone marrow films were prepared for counting. The results indicated that pronormoblasts and normoblasts decreased after all the three exposures both in control and experimental groups, but in the drug treated groups, counts were always higher than their respective controls and recovery was also faster. It is, therefore, concluded that WR-2721 shows an appreciable protective potential against radiation induced changes.