模拟高原不同时间缺氧暴露对大鼠红细胞结构与功能的影响

目的:初步探讨模拟高原不同时间缺氧暴露对大鼠红细胞结构与功能的影响及机制。方法:40只雄性SD大鼠随机分成5组(每组8只):常氧组、缺氧1周组、缺氧2周组、缺氧3周组和缺氧4周组。各缺氧组大鼠置于模拟海拔5 800 m的低压舱内,连续暴露相应时间后,采集全血,测定血常规、红细胞变形指数和红细胞渗透脆性,绘制血红蛋白氧解离曲线,分析计算红细胞凋亡率,观察骨髓切片病理学变化。结果:与常氧组相比,各缺氧组红细胞计数、血红蛋白含量、红细胞平均体积、红细胞平均血红蛋白含量和磷脂酰丝氨酸外翻率均显著增加(P0.01),血红蛋白氧饱和度为50%时的氧分压显著增大(P0.05),骨髓红系增生增加,红细胞变形指数及渗透脆性显著降低(P0.01),血红蛋白氧离曲线右移。结论:在模拟高原缺氧初期,外周血中红细胞的结构与功能发生代偿性改变以利于高原习服;但是,随着缺氧时间的延长,血管内滞留过多的异常红细胞容易导致血栓形成及微循环障碍,并加重机体的组织细胞缺氧。

Effects of hypoxia exposure for different time on structure and function of red blood cells in rats

AIM: To investigate the effects of hypoxia exposure on the structure and function of erythrocytes in rats at different time. METHODS: Male SD rats (n=40) were randomly divided into 5 groups, normal control group, 1-week hypoxia group, 2-week hypoxia group, 3-week hypoxia group and 4-week hypoxia group, with 8 rats per group. The rats in hypoxia groups were placed in the simulated 5 800 m of high altitude in a hypobaric chamber for different time. The values of detected blood, erythrocyte deformation index, erythrocyte osmotic fragility, erythrocyte oxygen dissociation, erythrocyte apoptosis and bone marrow biopsy were determined. RESULTS: Compared with normal control group, the red blood cell count, hemoglobin content, mean corpuscular volume and mean corpuscular hemoglobin significantly increased (P<0.01). Eversion rate of phosphatidylserine of erythrocytes increased. Oxygen half-saturation of hemoglobin increased (P<0.05). Bone marrow erythroid proliferation increased. The erythrocyte deformation index and erythrocyte osmotic fragility decreased significantly (P<0.01). In addition, oxygen dissociation curves shifted to the right. CONCLUSION: In the early stage of hypoxia, compared with normal control group, the changes of erythrocyte structure and function increase the oxygen supply to the tissue and are conducive to adapting to the plateau. However, with the extension of hypoxia, excessive erythrocytosis results in thrombosis, microcirculation disturbance and aggravating tissue hypoxia.