Abstract:

Objective To discuss the effect of salidroside on the apoptosis of the bone marrow CD71+ nucleated red blood cells（RBC） in the rat model of high altitude polycythemia （HAPC），and to clarify its mechanism. Methods orty-five male SD rats were randomly divided into control group （exposed to 1 500 m altitude + NaCl solution）， model group （exposed to 5 000 m altitude + NaCl solution）， and drug group （exposed to 5 000 m altitude + 0.15 g·kg^－1·d^－1 salidroside），and there were 15 rats in each group. The RBC counts， hemoglobin （Hb） levels， and hematocrit （HCT） levels of the rats in various groups were detected； flow cytometry was used to detect the percentages of bone marrow CD71+nucleated RBC， apoptotic rates of bone marrow CD71+nucleated RBC， levels of mitochondrial membrane potential （MMP） and expression levels of cysteinyl aspartate-specific protease-3 （Caspase-3） in bone marrow CD71+nucleated RBC of the rats in various groups； Western blotting method was used to detect the expression levels of B-cell lymphoma-2 （Bcl-2）， Bcl2-associated X protein （Bax） ，and cysteinyl aspartate-specific protease-9 （Caspase-9） proteins in bone marrow CD71+nucleated RBC of the rats in various groups. Results Compared with control group， the RBC count， Hb level， HCT level of the rats in model group were increased （P<0.01）， and the percentage and apoptotic rate of bone marrow CD71+nucleated RBC were increased （P<0.01）， and the expression levels of Bax， Caspase-9， and Caspase-3 proteins in the bone marrow CD71+nucleated RBC were increased （P<0.05）. Compared with model group， the percentage of bone marrow CD71+nucleated RBC of the rats in drug group was decreased （P<0.01）， the apoptotic rate of bone marrow CD71+nucleated RBC（P<0.01）， and the MMP level in the bone marrow CD71+nucleated RBC were increased （P<0.05）， and the expression levels of Caspase-3， Bax， and Caspase-9 proteins in the bone marrow CD71+nucleated RBC were decreased （P<0.01）. Conclusion Salidroside can effectively inhibit the increasing of apoptosis of nucleated RBC in bone marrow of the HAPC rats and improve the excessive accumulation of the RBC caused by hypoxia， which may have a certain preventive and protective effect in the pathogenesis of HAPC in the rats.

Key words: High altitude polycythemia, Salidroside, Bone marrow mononuclear cells, Apoptosis, Red blood cells