A rat model of high altitude polycythemia rapidly established by hypobaric hypoxia exposure

Objective To investigate the effects of simple hypobaric hypoxia on parameters of hematology and blood rheology in order to establish a rat model of simulated high altitude polycythemia(HAPC) for the study of pathophysiologic mechanisms and medical prevention and treatment of HAPC.Methods Fortyeight male Wistar rats were randomly divided into three normal control groups and three hypoxia model groups.Normal control group rats were bred in normoxia conditions,and hypoxia group rats were subjected to hypoxic exposure for 8 hours per day at simulated 5 500 m high altitude in a hypobaric chamber.After hypoxic exposure for 2,4,12 weeks,one group of normal control and hypoxia model rats were killed and blood was collected,respectively.Then parameters of erythrocyte and blood rheology were examined.Results Mucous membrane of hypoxia model rats showed obviously cyanosis after 2 weeks hypoxic exposure.Hemoglobin concentration of hypoxia model rats were beyond 210 g/L after 2 weeks,4 weeks and 12 weeks hypoxia exposure and significantly increased than that of normal control rats respectively.Besides,RBC counts,hematocrit,whole blood viscosity,erythrocyte aggregation index of hypoxia model rats were all notably higher than those of normal control rats respectively.Conclusion A rat model of high altitude polycythemia can be rapidly established by hypobaric hypoxia exposure at simulated 5 500 m high altitude for 8 hours daily.

不同低氧胁迫方式构建SD大鼠高原肺水肿模型的比较研究

目的研究不同低氧胁迫方式构建高原肺水肿模型的效果。方法将60只SD大鼠随机分为3组:对照组(海拔400 m),低压氧舱组(模拟海拔6000 m低氧胁迫48 h),实地低氧组(海拔4200 m低氧胁迫28 d);每组20只。通过检测实验大鼠肺组织的干湿比、形态学和病理生理学特征、关键基因水通道蛋白1(aquaporin-1,AQP-1)和血管内皮生长因子(vascular endothelial growth factor,VEGF)表达,以及氧化应激水平,比较不同低氧胁迫方式构建SD大鼠高原肺水肿模型的效果。结果与对照组相比,低压氧舱组和实地低氧组大鼠的肺动脉压和肺组织含水量均显著升高(均P<0.01),而氧分压及氧饱和度显著下降(均P<0.01)。对照组肺组织形态在光镜和电镜下均显示结构正常;低压氧舱组和实地低氧组肺组织在光镜下均可见肺泡壁且肺泡间隔明显增宽,大量红细胞和炎性细胞溢出,且在肺泡间隔出现明显水肿。两实验组大鼠肺组织中AQP-1 mRNA和蛋白水平均较对照组明显升高(均P<0.01),VEGF mRNA和蛋白水平均较对照组明显降低(均P<0.01),而且血清中谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)和超氧化物歧化酶(superoxide dismutase,SOD)水平明显降低,丙二醛(malondialdehyde,MDA)水平明显升高。结论低压氧舱模拟海拔6000 m低氧胁迫48 h,以及海拔4200 m实地低氧胁迫28 d,均可有效构建SD大鼠高原肺水肿模型;其中,应用低压氧舱构建SD大鼠高原肺水肿模型相对更占优势。