Van Loon J J, Bervoets D J, Burger E H, Dieudonné S C, Hagen J W, Semeins C M, Doulabi B Z, Veldhuijzen J P
ACTA-VU, Department of Oral Cell Biology, Amsterdam, The Netherlands.
J Bone Miner Res. 1995 Apr;10(4):550-7. doi: 10.1002/jbmr.5650100407.
Mechanical loading plays an important role in the development and maintenance of skeletal tissues. Subnormal mechanical stress as a result of bed rest, immobilization, but also in spaceflight, results in a decreased bone mass and disuse osteoporosis, whereas supranormal loads upon extremities result in an increased bone mass. In this first in vitro experiment with complete fetal mouse cartilaginous long bones, cultured under microgravity conditions, we studied growth, glucose utilization, collagen synthesis, and mineral metabolism, during a 4-day culture period in space. There was no change in percent length increase and collagen synthesis under microgravity compared with in-flight 1x gravity. Glucose utilization and mineralization were decreased under microgravity. In addition, mineral resorption, as measured by 45Ca release, was increased. These data suggest that weightlessness has modulating effects on skeletal tissue cells. Loss of bone during spaceflight could be the result of both impaired mineralization as well as increased resorption.
机械负荷在骨骼组织的发育和维持中起着重要作用。卧床休息、固定不动以及太空飞行导致的机械应力不足会导致骨量减少和废用性骨质疏松，而肢体承受超常负荷则会导致骨量增加。在首次使用完整的胎儿小鼠软骨长骨进行的体外实验中，我们在微重力条件下对其进行培养，并在太空4天的培养期内研究了其生长、葡萄糖利用、胶原蛋白合成和矿物质代谢。与飞行中的1倍重力相比，微重力条件下的长度增加百分比和胶原蛋白合成没有变化。微重力条件下葡萄糖利用和矿化减少。此外，通过45Ca释放测量的矿物质吸收增加。这些数据表明失重对骨骼组织细胞具有调节作用。太空飞行期间的骨质流失可能是矿化受损和吸收增加共同作用的结果。
