CELL BIOLOGY OF MEGAKARYOCYTOPOIESIS

骨髓巨核细胞通过以下途径产生血小板 细胞质的碎裂和碎片的释放 进入血液循环。有大量证据表明 巨核细胞的成熟受控于 通过体液机制循环中的血小板数量。一 促血小板生成的来源是血浆中的 血小板减少性动物。这种血浆中的一定比例 刺激体内的血小板生成。因此，它的效果 分离的分离的血小板减少性血浆 将对巨核细胞进行研究。两种体外刺激物 巨核细胞集落、白细胞介素3和巨核细胞集落 增效剂，也将研究其对隔离的影响 巨核细胞。这些研究将与 确定巨核细胞是否存在的意图 成熟度可以控制在可识别的 巨核细胞。这些药物对巨核细胞的影响 将在三个领域进行研究：新陈代谢、形态和 成熟。利用放射性标记的前体，蛋白质合成和 将对磷酸化和脂质合成进行研究。分析 材料将使用电泳法和 层析程序。糖酵解的研究将通过 测量葡萄糖摄取和乳酸产量。形态学 将使用阶段和扫描和 透射电子显微镜。细胞骨架结构将是 使用免疫荧光和免疫电子技术进行研究 显微镜。成熟度将用脉冲追踪法进行研究 用~3H-胸腺嘧啶核苷和跟随运动的实验 通过由以下因素确定的连续成熟度进行标记 Wright-Giemsa染色标本。此外，对 将研究巨核细胞倍性分布。此外 荧光激活的细胞分选将用于分离 巨核细胞倍性。分离的细胞，将用于 调查可能存在的新陈代谢差异 不同倍体的巨核细胞。这些研究提供了 生物化学和生物化学研究的长期计划的基础 在巨核细胞成熟期间发生的代谢变化， 并解释了促血小板生成的作用机制 细胞水平上的刺激物。此外，这些研究可能 建立了一种有效的体外纯化方法。 促血小板生成素。总体而言，更好地了解对 巨核细胞生成将是这个项目的结果。

Bone marrow megakaryocytes give rise to blood platelets by fragmentation of their cytoplasm and release of the fragments into the blood stream. There is considerable evidence that megakaryocyte maturation is controlled by changes in the circulating platelet population via a humoral mechanism. One source of a thrombopoietic stimulation is the plasma of thrombocytopenic animals. A certain fraction of this plasma stimulates platelet production in vivo. Therefore, the effect of fractionated thrombocytopenic plasma on isolated megakaryocytes will be studied. Two in vitro stimulators of megakaryocytic colonies, interleukin-3 and megakaryocyte colony potentiator, will also be studied for their effects on isolated megakaryocytes. These studies will be performed with the intention of determining whether or not megakaryocyte maturation can be controlled at the level of the recognizable megakaryocyte. The effect of these agents on megakaryocytes will be investigated in three areas: metabolism, morphology and maturation. Using radiolabeled precursors, protein synthesis and phosphorylation and lipid synthesis will be studied. Analysis of material will be performed using electrophoretic and chromatographic procedures. Glycolysis will be studied by measuring glucose uptake and lactic acid production. Morphology will be investigated using phase and both scanning and transmission electron microscopy. Cytoskeletal structures will be studied using immunofluorescence and immunoelectron microscopy. Maturation will be studied using pulse chase experiments with 3H-thymidine and following the movement of label through successive levels of maturation as determined by Wright-Giemsa stained specimens. Also the effect on megakaryocyte ploidy distribution will be studied. In addition fluorescent activated cell sorting will be used to separate megakaryocytes by ploidy. The separated cells, will be used to investigate the possible metabolic differences between megakaryocytes of different ploidys. These studies provide the basis for a long term program on the study of biochemical and metabolic changes that occur during megakaryocyte maturation, as well as explaining the mechanism of action of thrombopoietic stimulators at the cellular level. In addition these studies may lead to a useful in vitro assay for the purification of thrombopoietin. Overall, a better understanding of the control of megakaryocytopoiesis will be the outcome of this project.