Radioprotection by MPG of mice ovaries exposed to sublethal gamma radiation doses at different postnatal ages.

Female Swiss albino mice were exposed at 1, 3 or 6 weeks of age respectively to sublethal doses (0.6, 1.2 and 2.4 Gy) of gamma radiation in the presence or absence of 2-mercaptopropionylglycine (MPG). Ovaries were histologically examined at different intervals after irradiation and the follicles were counted. Most follicular depletion had occurred already at postirradiation day 1 and the depletion then gradually continued. At day 35 after irradiation a few follicles could still be found in mice exposed at 1 week of age while all follicles were eliminated in mice exposed at 3 and 6 weeks of age. In MPG-treated animals the depletion of follicles was significantly less pronounced and obviously MPG to some degree protected the ovaries from radiation damage.