FUNCTIONAL STUDIES OF OSTEOBLASTS

成骨细胞的功能研究

• 批准号: 3223233
• 负责人: Carol V Gay
• 金额: $ 15.94万
• 依托单位: PENNSYLVANIA STATE UNIVERSITY, THE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-04-01 至 1994-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3223233
• 关键词: adenosinetriphosphatase; apical membrane; basolateral membrane; bone development; calcium; calcium channel; calcium channel blockers; calcium flux; cell membrane; cell type; chickens; electron microscopy; enzyme linked immunosorbent assay; fibroblasts; immunocytochemistry; immunoregulation; intracellular transport; laboratory rat; membrane reconstitution /synthesis; membrane transport proteins; normal ossification; osteoblasts; physiologic bone resorption; sodium

This proposal is in response to our earlier histochemical finding that suggests that osteoblasts possess a highly active plasma membrane Ca++- translocating ATPase on the apicial and lateral (non-bone) sides of the cell. Since the role of this enzyme is outwardly-directed calcium translocation in all other cells that have been studied, it is expected that the Ca-ATPase in osteoblasts will also move calcium out of the cell. The ATP-hydrolyzing capacity of the Ca-ATPase, its Ca++ translocating properties and its regulation by substances known to stimulate osteoblasts will be examined in vesicles prepared from the plasma membrane of osteoblasts. In addition, demonstration of the existence of a Na/Ca exchanger and calcium channels will be sought. It is postulated that the Ca-ATPase exists on the apico-lateral sides of the osteoblast and that a Na/Ca exchanger may be present on the basal side of the cell. Two sources of osteoblasts will be utilized: (1) osteoblasts derived from neonate rat calvaria which represent intramembranous bone formation and, hence, the cranio-facial skeleton; and (2) trabecular bone of avian medullary bone, a highly metabolically active bone, which represents bone derived from the endochondral ossification process. The studies are intended to provide insight into mechanisms of osteoblast function, cells which are important in cranio-facial development, orthopedics and understanding diseases of bone loss in which decreased bone formation has been noted.

该提议是对我们之前的组织化学发现的回应 表明成骨细胞具有高度活跃的质膜 Ca++- 在根尖和外侧（非骨）侧易位 ATP 酶 细胞。 由于这种酶的作用是向外定向钙 已研究的所有其他细胞中的易位，预计 成骨细胞中的 Ca-ATP 酶也会将钙移出细胞。 Ca-ATP 酶的 ATP 水解能力，其 Ca++ 易位 已知刺激成骨细胞的物质的特性及其调节 将在由质膜制备的囊泡中进行检查 成骨细胞。 此外，证明了Na/Ca的存在 将寻找交换器和钙通道。 假设 Ca-ATP酶存在于成骨细胞的顶端外侧，并且 Na/Ca 交换器可能存在于细胞的基底侧。 两个来源 将利用的成骨细胞：（1）来自新生大鼠的成骨细胞 颅骨代表膜内骨形成，因此， 颅面骨骼； (2) 禽类髓骨的骨小梁，a 高度代谢活跃的骨骼，代表来自 软骨内骨化过程。 这些研究旨在提供 深入了解成骨细胞功能的机制，重要的细胞 在颅面发育、骨科和了解疾病方面 已注意到骨形成减少的骨质流失。