中文摘要：

目的观察高原红细胞增多症（HAPC）大鼠骨髓CD71＋细胞促红细胞生成素受体（EpoR）表达及分布变化,并探讨其意义。方法将48只雄性SD大鼠随机分为HAPC组和对照组,每组24只。HAPC组和对照组分别在海拔4 300、2 250 m自然环境下饲养。饲养40天行血液学参数[RBC、Hb、红细胞压积（HCT）、动脉血氧饱和度（Sa O2）]和骨髓细胞分类计数检测,HAPC组RBC、Hb、HCT及红系细胞数量、中幼红细胞数量、晚幼红细胞数量均高于对照组,Sa O2低于对照组（P均〈0.05）,证实HAPC模型制备成功。两组均采用密度梯度离心法制备骨髓单个核细胞（MNC）悬液,CCK8法检测MNC增殖能力（以OD450表示）,单层半固体培养法检测红系集落形成单位（CFU-E）数量。采用免疫磁珠分选法从两组MNC悬液中分选CD71＋细胞,免疫荧光法观察细胞膜表面EpoR荧光情况,ELISA法检测细胞膜和细胞质EpoR表达,Real-time PCR法和Western blotting法检测EpoR mRNA和蛋白相对表达量。结果 HAPC组和对照组OD450分别为1.54±0.04、1.17±0.05,CFU-E数量分别为（61.25±6.84）、（12.90±4.39）个;两组比较P均〈0.01。免疫荧光显微镜下可见两组细胞膜表面均有环形或半环形的绿色荧光,但HAPC组细胞膜表面EpoR荧光强度和表达EpoR荧光的细胞数量均高于对照组。HAPC组及对照组CD71＋细胞膜EpoR表达分别为2.41±0.03、1.55±0.06（P〈0.05）;细胞质EpoR表达分别为96.39±0.42、94.49±0.65（P〉0.05）。HAPC组CD71＋细胞EpoR mRNA和蛋白相对表达量均高于对照组（P均〈0.05）。结论 HAPC大鼠骨髓CD71＋细胞EpoR表达升高,分布多集中于细胞膜表面;上述变化可能通过促进MNC及骨髓红系细胞增殖而参与HAPC的发生、发展。

英文摘要：

Objective To observe the changes of expression and distribution of EpoR in myeloid CD71＋cells of rats with high altitude polycythemia（ HAPC） and to investigate the significance. Methods Forty-eight male SD rats were randomly divided into the HAPC group and control group,with 24 rats in each group. Rats in the HAPC group and control group were fed for 40 days under natural environment at altitude of 4300 meters and 2250 meters respectively and verified by hematology parameters [RBC,Hb,hematocrit（ HCT）,arterial oxygen saturation（ Sa O2） ]detection and bone marrow cells counts. RBC,Hb,HCT,erythrocytic proportion,polychromatic erythroblast proportion and orthochromatic proportion of the HAPC group were higher than those of the control group,Sa O2 was lower than the control group（ all P 〈 0. 05）,which indicated that the establishment of rat model with HAPC was successful. We used the density gradient centrifugation to prepare the bone marrow mononuclear cell（ MNC） suspension in both groups. The proliferation of MNC in the two groups was detected by CCK8（ manifested by OD450） and the colony formation of Colony Forming Unit-erythroid（ CFU-E）was detected by ingle layer semisolid culture method. Myeloid CD71＋cells were separated from MNC in the two groups by magnetic activated cell sorting method. Then EpoR fluorescence on the membrane surface of the two groups was observed by immunofluorescence assay. EpoR expression of cell membrane and cytoplasm was measured by ELISA. The relative expression of EpoR mRNA and protein was detected by real-time PCR and Western blotting. Results The OD450 of HAPC group and control group were 1. 54 ± 0. 035 and 1. 17 ± 0. 05,respectively; the CFU-E colony formation of the two groups were61. 25 ± 6. 84 and 12. 90 ± 4. 39,respectively（ all P 〈 0. 01）. The immunofluorescence results showed that a ring or semiannular green fluorescence appeared on the surface of cell membrane in the two groups. However,the fluorescence intensity of EpoR on cell surfac