Vailas A C, Deluna D M, Lewis L L, Curwin S L, Roy R R, Alford E K
Department of Kinesiology, University of California, Los Angeles 90024-1568.
J Appl Physiol (1985). 1988 Jul;65(1):373-6. doi: 10.1152/jappl.1988.65.1.373.
The rat hindlimb suspension model was used to ascertain the importance of ground reaction forces in maintaining bone and tendon homeostasis. Young female Sprague-Dawley rats were randomly assigned to either a suspended or a nonsuspended group. After 28 days, femur bones and patellar tendons were obtained for morphological and biochemical analyses. Prolonged suspension induced a significant change in the geometric configuration of the femur middiaphysis by increasing the minimum diameter (12%) without any significant alterations in cortical area, density, mineral, and collagen concentrations. Femur wet weight, length, DNA, and uronic acid concentrations of suspended animals were not significantly different from bones of nonsuspended rats. However, the collagen and proteoglycan concentrations in patellar tendons of suspended rats were 28% lower than the concentrations of matrix proteins in tissues obtained from nonsuspended animals. These data suggest that elimination of ground reaction forces induces alterations in tendon composition and femur diaphyseal shape by changing regional rates in bone remodeling and localized tendon strain. Therefore it appears that ground reaction forces are an important factor in the maintenance of cortical bone and patellar tendon homeostasis during weight-bearing conditions.
采用大鼠后肢悬吊模型来确定地面反作用力在维持骨骼和肌腱内环境稳定中的重要性。将年轻雌性Sprague-Dawley大鼠随机分为悬吊组或非悬吊组。28天后，获取股骨和髌腱进行形态学和生化分析。长时间悬吊导致股骨中骨干的几何形态发生显著变化，最小直径增加了12%，而皮质面积、密度、矿物质和胶原蛋白浓度没有任何显著改变。悬吊动物的股骨湿重、长度、DNA和糖醛酸浓度与非悬吊大鼠的骨骼无显著差异。然而，悬吊大鼠髌腱中的胶原蛋白和蛋白聚糖浓度比从非悬吊动物获得的组织中的基质蛋白浓度低28%。这些数据表明，消除地面反作用力会通过改变骨重塑区域速率和局部肌腱应变来诱导肌腱组成和股骨干形状的改变。因此，地面反作用力似乎是负重条件下维持皮质骨和髌腱内环境稳定的一个重要因素。
