RhG-CSF improves radiation-induced myelosuppression and survival in the canine exposed to fission neutron irradiation

Fission-neutron radiation damage is hard to treat due to its critical injuries to hematopoietic and gastrointestinal systems,and so far few data are available on the therapeutic measures for neutron-radiation syndrome. this study was designed to test the effects of recombinant human granulocyte colony-stimulating factor (rhg-csf) in dogs which had received 2.3 gy mixed fission-neutron-γ irradiation with a high ratio of neutrons (~90%). following irradiation,rhg-csf treatment induced 100% survival versus 60% in controls. only two of five rhg-csf-treated dogs experienced leukopenia (white blood cells [wbc] count < 1.0 × 10 9/l) and neutropenia (neutrophil [anc] count < 0.5 × 10 9/l),whereas all irradiated controls displayed a profound period of leukopenia and neutropenia. furthermore,administration of rhg-csf significantly delayed the onset of leukopenia and reduced the duration of leucopenia as compared with controls. in addition,individual dogs in the rhg-csf-treated group exhibited evident differences in rhg-csf responsiveness after neutron-irradiation. finally,histopathological evaluation of the surviving dogs revealed that the incidence and severity of bone marrow,thymus and spleen damage decreased in rhg-csf-treated dogs as compared with surviving controls. thus,these results demonstrated that rhg-csf administration enhanced recovery of myelopoiesis and survival after neutron-irradiation.