Some Data on Mechanism of Leukopenia and Leukocytosis Following Irradiation

Abstract

Abstract 1. In rabbits irradiated with 150 to 600 r, granulocytosis is preceded by a prompt significant granulocytopenia developing 5-15 minutes after irradiation but persisting for a short time. 2. The plasma taken at the minimum of the initial granulocytopenia produced a similar two-phase reaction when injected into normal animals: a promptly developing significant granulocytopenia persisting for a short period followed by prolonged granulocytosis. Prolonged thrombocytopenia might be induced by the very same plasma. 3. The above-mentioned reactions may he reproduced satisfactorily with the administration of dilute starch solutions. 4. On the basis of the results obtained, it seems likely that the agent demonstrable in the plasma after irradiation, and influencing the level of circulating granulocytes and thrombocytes, is not a toxin (leukotoxin) but a substance that may be formed following physiologic stimuli as well.