In three recent articles Warren and Draeger,1 Warren2 and Draeger and Warren3 respectively described the occurrence of petechial hemorrhages and thrombopenia in the victims of Hiroshima and Nagasaki and in the animals which were tested at Bikini. Allen and Jacobson4 found that hyperheparinemia and hemorrhagic manifestations occurred in animals after acute exposure of the whole body to high ionizing irradiations in the midlethal range. The increase of heparin in the circulation, thrombopenia and petechiae were the outstanding abnormalities noted in irradiated dogs.
Copley and Robb5 have demonstrated that heparin produces thrombopenia in vivo and a decrease of single platelets in vitro. Copley and Houlihan6 were able to explain this by showing that isolated platelets are agglutinated when incubated with heparin plasma. Thus heparin, although highly active as an anticoagulant, not only does not inhibit platelet agglutination, but induces it. This accounts for the thrombopenia.