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.