Stimulation of Thrombocytopoiesis in Irradiated Mice

Platelet depletion in mice, by injection of heterologous anti-platelet serum (APS), resulted in apparent stimulation of megakaryocytopoiesis as evidenced by a subsequent over-compensation of the level of circulating platelets. Injection of APS immediately before or after exposure to sublethal radiation or a day after exposure appeared to modify the response to radiation. Radiation-induced thrombocytopenia was neither as severe nor as prolonged in animals so treated as in irradiated controls. More chronic thrombocytopenia at the time of irradiation, however, appeared to increase the radiosensitivity of the megakaryocytic system.