Radioprotective effect of misoprostol on mouse spermatogonial stem cells

The radioprotective effects of misoprostol, a synthetic stable analogue of prostaglandin E-1, on spermatogonial stem cells of C3H/HeH x 101/F1 hybrid mice (3H1) were analysed by establishing dose-response relationships for st em cell killing by X-rays in mice that were pretreated with misoprostol, Sp ermatogonial stem cell killing was studied through determination of the per centage of tubular cross-sections showing repopulation at 10 days after irr adiation. In control mice, the D-0 values ranged between 1.7 and 3.6 Gy, de pendent on the stage of the cycle of the seminiferous epithelium the cells were in. As found previously, proliferating spermatogonial stem cells were much more radioresistant than quiescent stem cells. In the misoprostol-pret reated animals the spermatogonial stem cells were more radioresistant, the D-0 values ranging from 3.6 to 5.0 Gy. Both proliferating and quiescent spe rmatogonial stem cells were protected by misoprostol, As the dose-response curves in control and misoprostol-pretreated mice showed about the same ext rapolation number to the y-axis it was concluded that the misoprostol pretr eatment did not alter the kinetics of the repopulation process.