SHORTENED PLATELET SURVIVAL AS A CAUSE OF THROMBOCYTOPENIA IN MICE WITH L1210 LEUKEMIA

  • 1 January 1980
    • journal article
    • research article
    • Vol. 40  (3) , 667-670
Abstract
Thrombocytopenia is a frequent complication of acute leukemias of humans and animals. To define the possible causes of this decrease in platelets, platelet kinetics were studied in mice after transplantation of 106 ascites cells from mice bearing L1210 leukemia. The circulating half-time of 51Cr-labeled platelets was reduced to approximately 1/2 that of controls when studied 1 or 3 days posttransplantation. Recovery of transfused 51Cr-labeled platelets was reduced to approximately 1/2 that in controls when studied 3 days after introduction of L1210 cells. Megakaryocyte concentration showed no change during the 5-day survival after i.v. infusion of leukemic cells but was increased on day 5 after i.p. inoculation with an average host survival of 7 days. Megakaryocyte diameter distributions were significantly shifted toward larger sizes beginning on day 2 after i.v. inoculation and on day 3 after i.p. inoculation. Twenty-four hour [3H]thymidine labeling indices of megakaryocytes were significantly increased beginning on day 3 after i.v. inoculation but were significantly decreased on days 5 and 6 after i.p. introduction of L1210 cells. The decrease in platelets in mice transplanted with L1210 leukemia apparently results primarily from shortened platelet survival and organ pooling. Megakaryocytes remain normal in concentration but increase in size, a usual response to decreases in platelet count.