Radiation sensitivity of small oocytes in immature mice. effect of gonadotropin treatment

The effect of pregnant mare serum gonadotropin on the survival of small oocytes of acutely irradiated immature mice was assessed by counting occytes on serial sections under the light microscope. Twenth-four hours after irradiation with 40 R the number of small oocytes was reduced to a few percent of that in unirradiated controls. The number of oocytes was a little higher in animals injected with gonadotropin before radiation exposure than in animals that were only irradiated. One week after radiation exposure very few small oocytes were seen in any of the irradiated ovaries regardless of treatment. Thus pregnant mare serum gonadotropin had no protective effect on the small oocytes of irradiated immature mice