Survival from partial-body irradiation (PBI) may be limited by the development of the late lung injury response of pneumonitis. Herein we investigated the hypothesis that acute hematopoietic depletion alters the onset and severity of lung disease in a mouse model. To establish depletion, C3H/HeJ mice received 8 Gy PBI with shielding of only the tibiae, ankles and feet. One week after irradiation, blood lymphocyte and neutrophil counts were each significantly reduced (P < 0.04) in these mice compared to levels in untreated controls or in mice receiving 16 Gy to the whole thorax only. All 8 Gy PBI mice survived to the experimental end point of 16 weeks postirradiation. To determine whether the hematopoietic depletion affects lung disease, groups of mice received 8 Gy PBI plus 8 Gy whole-thorax irradiation (total lung dose of 16 Gy) or 16 Gy whole-thorax irradiation only. The weight loss, survival to onset of respiratory distress (P = 0.17) and pneumonitis score (P = 0.96) of mice that received 8 Gy PBI plus 8 Gy whole-thorax irradiation were not significantly different from those of mice receiving 16 Gy whole-thorax irradiation only. Mice in respiratory distress from PBI plus whole-thorax irradiation had significantly reduced (P = 0.02) blood monocyte counts compared to levels in distressed, whole-thorax irradiated mice, and symptomatic pneumonitis was associated with increased blood neutrophil counts (P = 0.04) relative to measures from irradiated, non-distressed mice. In conclusion, survivable acute hematopoietic depletion by partial-body irradiation did not alter the onset or severity of lethal pneumonitis in the C3H/HeJ mouse model.

部分身体照射 (PBI) 的存活可能会受到肺炎晚期肺损伤反应的发展的限制。在此，我们研究了急性造血耗竭改变小鼠模型中肺部疾病的发作和严重程度的假设。为了建立消耗，C3H/HeJ 小鼠接受 8 Gy PBI，仅屏蔽胫骨、脚踝和脚。照射后1周，血淋巴细胞和中性粒细胞计数均显着降低（P< 0.04) 在这些小鼠中与未治疗对照组或仅对整个胸部接受 16 Gy 的小鼠中的水平进行比较。所有 8 Gy PBI 小鼠均存活至照射后 16 周的实验终点。为了确定造血耗竭是否影响肺部疾病，小鼠组接受了 8 Gy PBI 加 8 Gy 全胸照射（肺总剂量为 16 Gy）或仅接受 16 Gy 全胸照射。接受 8 Gy PBI 加 8 Gy 全胸照射的小鼠的体重减轻、呼吸窘迫发作的存活率 ( P = 0.17) 和肺炎评分 ( P = 0.96) 与接受 16 Gy 全胸照射的小鼠没有显着差异。仅胸部照射。PBI 加全胸照射引起的呼吸窘迫小鼠显着减少（P= 0.02) 血液单核细胞计数与痛苦的、全胸辐照小鼠的水平相比，症状性肺炎与血液中性粒细胞计数增加有关 ( P = 0.04)，相对于辐照、非痛苦小鼠的测量。总之，在 C3H/HeJ 小鼠模型中，局部照射引起的可存活的急性造血耗竭并没有改变致死性肺炎的发作或严重程度。