Bobik R, Dabrowski Z
1epartment of Animal Physiology, Institute of Zoology, Jagiellonian University, Cracow, Poland.
Ann Hematol. 1995 Feb;70(2):91-5. doi: 10.1007/BF01834387.
The incidence of megakaryocytic emperipolesis was studied in the bone marrow of normal and X-irradiated mice. Two groups of mice received total body irradiation with a single dose of 5 Gy and one of the two groups had been treated with a radioprotective drug, ethiofos (WR-2721), before irradiation. Mice from a third group remained unexposed to irradiation and served as controls. The Wright-Giemsa stained bone marrow smears were analyzed every 5 days during a 30-day period, starting 1 day after irradiation. The number of megakaryocytes exhibiting the phenomenon was determined and expressed as an average value for every experimental group. The frequency of megakaryocytic emperipolesis was less than 15% of megakaryocytes from control smears but increased to 34% in mice that had only been irradiated and to 43% when mice were treated with WR-2721 before irradiation. In the last case, i.e., irradiation and treatment with a radioprotective drug, a positive correlation between the macrocytic megakaryocytes and elevated emperipolesis was noted. Under light microscopy, there were no signs of phagocytosis; engulfed cells remained unaltered with their normal structure intact. Granulocytic, erythroid, and lymphoid cells appeared to be the most frequent marrow cells engulfed by mature megakaryocytes. The number of incorporated cells in one megakaryocyte ranged from 1 to 3, though occasionally more than 6 were seen in macrocytic megakaryocytes. Based on our findings and on a review of the associated literature, we believe emperipolesis is an interesting cellular phenomenon related to the fast passage of marrow cells across the marrow-blood barrier, especially through the cytoplasm of megakaryocytes in response to an increased demand for cell delivery. The high demand for cell delivery which occurs after irradiation may cause certain mature bone marrow cells to take a transmegakaryocyte path to enter the circulation of the blood. Irradiation seems to have an immediate effect (observed after 24 h) on emperipolesis, suggesting that a humoral factor is involved in the pathogenesis.
研究了正常小鼠和经X射线照射的小鼠骨髓中巨核细胞 emperipolesis 的发生率。两组小鼠接受单次剂量5 Gy的全身照射，其中一组在照射前用放射防护药物乙磺半胱乙酯（WR - 2721）进行了处理。第三组小鼠未接受照射，作为对照。在照射后第1天开始的30天内，每5天对经瑞氏-吉姆萨染色的骨髓涂片进行分析。确定出现该现象的巨核细胞数量，并表示为每个实验组的平均值。巨核细胞 emperipolesis 的频率在对照涂片的巨核细胞中不到15%，但在仅接受照射的小鼠中增加到34%，在照射前用WR - 2721处理的小鼠中增加到43%。在最后一种情况下，即照射并用放射防护药物处理，观察到巨核细胞与emperipolesis升高之间存在正相关。在光学显微镜下，没有吞噬作用的迹象；被吞噬的细胞保持不变，其正常结构完整。粒细胞、红细胞和淋巴细胞似乎是被成熟巨核细胞吞噬的最常见骨髓细胞。一个巨核细胞中被纳入的细胞数量从1到3不等，不过在巨核细胞中偶尔可见超过6个。基于我们的研究结果以及对相关文献的回顾，我们认为emperipolesis是一种有趣的细胞现象，与骨髓细胞快速穿过骨髓-血液屏障有关，特别是通过巨核细胞的细胞质以应对细胞输送需求的增加。照射后出现的对细胞输送的高需求可能导致某些成熟骨髓细胞采取经巨核细胞途径进入血液循环。照射似乎对emperipolesis有即时影响（在24小时后观察到），表明发病机制中涉及一种体液因子。
