Multi-organ acute and delayed effects following exposure to neutron radiation.

Neutron radiation exposure is a life-threatening consequence of nuclear disasters. To determine the effect of high dose neutron exposures on late responding organs, we assessed survival and characterized organ-specific injuries in adult male and female rats exposed to whole-body 2-10 Gy high linear energy transfer fast neutrons with 5%-8% bone marrow shielding. Survival through the acute and delayed sequelae of organ radiation injury was monitored for 1 year. Longitudinal secondary outcomes, including body weight, hematology, respiration, blood urea nitrogen, urinary proteomics and metabolomics, and cataract formation were assessed. During the acute sequelae of gastrointestinal and hematopoietic injury, neutron irradiation was 1.5-1.6 times more damaging than equivalent doses of X-ray. For late-responding organs, the relative biological effect of neutrons was 1.6 for the lung and 1.3 for the kidney. Urine proteomic and metabolomic profiles exhibited a time- and dose-dependent dysregulation. Altered proteins were associated with oxidative stress and renal injury.