The radioprotective effects of misoprostol, a synthetic stable
analogue of prostaglandin E1, on
spermatogonial stem cells of C3H/HeH×101/F1 hybrid mice (3H1)
were analysed by establishing
dose–response relationships for stem cell killing by X-rays in mice
that were pretreated with
misoprostol. Spermatogonial stem cell killing was studied through determination
of the percentage
of tubular cross-sections showing repopulation at 10 days after irradiation.
In control mice, the D0
values ranged between 1·7 and 3·6 Gy, dependent 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-pretreated
animals the
spermatogonial stem cells were more radioresistant, the D0 values
ranging from 3·6 to 5·0 Gy. Both
proliferating and quiescent spermatogonial stem cells were protected by
misoprostol. As the
dose–response curves in control and misoprostol-pretreated mice showed
about the same
extrapolation number to the y-axis it was concluded that the misoprostol
pretreatment did not
alter the kinetics of the repopulation process.
Unique Epigenetic Programming Distinguishes Regenerative Spermatogonial Stem Cells in the Developing Mouse Testis