Objective: To investigate the effects of different doses of nuclei exposure at different time on morbidity, mortality, and damage indicators in a rat model of decompression sickness caused by rapid flotation escape at a large depth. Methods: Eighty male SD rats were randomly divided into blank control group, escape control group and six intervention groups (escape at 4 hours after 4 Gy radiation, escape at 4 hours after 6 Gy radiation, escape at 4 hours after 12 Gy radiation, escape at 8 hours after 4 Gy radiation, escape at 8 hours after 6 Gy radiation, escape at 8 hours after 12 Gy radiation). Rats in intervention groups were exposed to different doses of γ-ray (4,6,12 Gy, respectively), and then were carried out a large depth and rapid buoyancy escape experiment (maximum pressure depth of 150 m). The changes of lung W/D, spleen index and plasma IL-1β levels were analyzed. Results: Compared with the blank control group, decompression sickness incidence and mortality of rats in escape groups after nuclear exposure were increased significantly. In 4 Gy and 6 Gy irradiation groups, higher morbidity and mortality were observed in rats which escaped at 4 h post nuclear exposure when compared with rats in 8 h groups. Consistent with the changes in morbidity and mortality, the wet / dry ratio of lung tissue, the pathological damage of lung tissue, and the decrease of spleen index showed the same trends: the changes were obvious at 4 h after lower doses nuclear radiation (4 Gy and 6 Gy), not at 8 h. However, these indicators all changed markedly at 4 and 8 h after higher doses nuclear radiation (12 Gy). Plasma IL-1β levels were significantly increased in each post-radiation exposure group when compared with the blank control group and the exposed control group. Conclusion: Nuclear radiation-induced lung injury, the damaged immune function and elevated plasma inflammatory factor concentrations increase the risk of decompression sickness after rapid ascent.
目的: 探讨不同剂量核暴露后不同时间对大深度快速上浮脱险致减压病大鼠模型的发病率、死亡率及损伤指标的影响。方法: 80只SD雄性大鼠,随机分成空白对照组、脱险对照组和6个干预组(4 Gy辐射后4 h脱险、6 Gy辐射后4 h脱险、12 Gy辐射后4 h脱险、4 Gy辐射后8 h脱险、6 Gy辐射后8 h脱险、12 Gy辐射8 h后脱险),每组10只。干预组动物先采用不同剂量γ射线外照射(4、6、12 Gy),再进行大深度快速上浮脱险实验(最大加压深度150 m),分析大鼠肺W/D、脾指数及血浆IL-1β的变化。结果: 与脱险对照组比较,核辐射后脱险大鼠的减压病发病率及死亡率明显上升。4 Gy、6 Gy照射4 h后上浮脱险的大鼠发病率和死亡率较照射8 h后高。12 Gy辐射后4 h及8 h脱险大鼠的减压病的发病率及死亡率均比低剂量照射组明显增高,死亡率尤其明显。和发病率及死亡率的变化相一致,肺组织湿/干比、肺组织病理损伤程度、脾指数下降也表现同样的变化趋势:较低剂量(4 Gy、6 Gy)辐射后4 h改变明显,8 h改变不明显,而高剂量(12 Gy)辐射后4、8 h均变化明显。和空白对照组及脱险对照组相比较,各辐射后脱险组的血浆IL-1β浓度均显著上升。结论: 核辐射引起放射性肺损伤、免疫功能下降及血浆炎症因子浓度升高,会增加大鼠快速上浮脱险致减压病的风险。.
Keywords: decompression sickness; inflammatory factors; lung injury; nuclear radiation; rapid floating escape; rats.