Jackson C W, Steward S A, Brown L K, Look A T
Br J Haematol. 1986 Sep;64(1):33-43. doi: 10.1111/j.1365-2141.1986.tb07571.x.
We examined the relationship between rat megakaryocyte buoyant density and maturation stage in continuous Percoll density gradients. An average of 88% of megakaryocytes had buoyant densities less than 1.054 g/ml. There was an inverse relationship between megakaryocyte buoyant density and maturation. Morphologically mature forms comprised 90% of the megakaryocytes with buoyant densities of 1.030-1.033 g/ml. In contrast, immature morphology was present in three-quarters of megakaryocytes with buoyant densities of 1.042-1.046 g/ml. These morphological findings were confirmed by [3H]thymidine labelling studies. Cell viability assessed by trypan blue exclusion was highest among more dense megakaryocytes of which the majority were immature. The lowest trypan blue exclusion was found in the less dense, predominantly mature megakaryocytes indicating that these cells are more susceptible to membrane damage during marrow suspension. Megakaryocyte DNA content distributions and platelet antigen levels, determined by two-colour flow cytometry, were also related to megakaryocyte density; the more dense megakaryocytes showed an approximately two-fold higher proportion of 8N cells and less platelet antibody binding than did less dense megakaryocytes. These studies suggest that megakaryocytes can be fractionated according to their buoyant densities into immature and mature populations suitable for molecular studies of differentiation.
我们在连续的Percoll密度梯度中研究了大鼠巨核细胞浮力密度与成熟阶段之间的关系。平均88%的巨核细胞浮力密度小于1.054 g/ml。巨核细胞浮力密度与成熟度呈负相关。形态学上成熟的巨核细胞占浮力密度为1.030 - 1.033 g/ml的巨核细胞的90%。相比之下，浮力密度为1.042 - 1.046 g/ml的巨核细胞中有四分之三呈现未成熟形态。这些形态学发现通过[³H]胸苷标记研究得到证实。通过台盼蓝排斥法评估的细胞活力在密度较高的巨核细胞中最高，其中大多数是未成熟的。在密度较低、主要为成熟的巨核细胞中发现台盼蓝排斥率最低，这表明这些细胞在骨髓悬浮过程中更容易受到膜损伤。通过双色流式细胞术测定的巨核细胞DNA含量分布和血小板抗原水平也与巨核细胞密度有关；密度较高的巨核细胞显示8N细胞的比例约为密度较低的巨核细胞的两倍，且血小板抗体结合较少。这些研究表明，巨核细胞可以根据其浮力密度分为适合分化分子研究的未成熟和成熟群体。
