Effects of S-2(3-aminopropylamino) ethylphosphorothioic acid (WR-2721) on the sensitivity of mouse spermatogonia A to radiation.

The sensitivity of spermatogonia to radiation was investigated in adult male Swiss albino mice after whole body exposure to three different doses (3, 6 and 8 Gy) of gamma radiation from a 60Co source with or without the drug S-2-(3-aminopropylamino) ethylphosphorothioic acid (WR-2721), at a dose of 400 mg/kg body weight. Spermatogonia A were counted in the seminiferous tubules of the testis, taken at post-irradiation intervals of 1, 2, 4, 7, 10, 14 and 28 days in both the drug treated and the control mice. The spermatogonia A count decreased after all three exposures. Severe depletion was observed with the higher dose (8 Gy) at early intervals. Recovery started at day 14, but normal counts could not be attained even up to the last interval. A similar pattern was observed with 6 and 3 Gy, but the number of counts was comparatively larger than with the 8 Gy group and the recovery was also faster in these groups. In all the drug treated groups, the spermatogonia A counts were always higher than their respective controls, showing an appreciable protective potential of WR-2721 against radiation.