Vico L, Chappard D, Alexandre C, Palle S, Minaire P, Riffat G, Morukov B, Rakhmanov S
Laboratoire de Biologie du Tissu Oseux, GIP 'Exercie', Groupe de'Etudes en Médecine et Physiologie Spatiale, Faculté de Médecine, Saint Etienne, France.
Bone Miner. 1987 Aug;2(5):383-94.
The effects of immobilization on bone mass and bone remodeling in patients with spinal cord injuries are known to simulate weightlessness-induced bone changes in astronauts. Nevertheless, immobilization has never been investigated using histomorphometric studies in healthy volunteers. Twenty healthy male volunteers participated in a '120 day bed-rest' experiment in the USSR. Bone biopsy cores of iliac crest were taken before and at the end of the period of bed-rest. The subjects were divided into five groups. Five subjects underwent a normal ambulatory life (control subjects); three subjects were placed on continuous bed-rest for 120 days (complete immobilization); four subjects were immobilized and underwent a controlled training program; four subjects were immobilized and received treatment with potassium diphosphonate (ethane-1,hydroxy-1,diphosphonate 900 mg/day, per os); and four subjects were immobilized and received diphosphonate plus physical exercise. Parameters of bone mass and bone cellular activities (osteoblastic formation and osteoclastic resorption) were measured using automatic and semi-automatic image analysis systems. Bone mass remained constant in each group. Cellular activity measurements showed that in completely immobilized men, the mineralization rate was lower than in controls without change in osteoid parameters; in contrast, osteoclastic parameters were increased. In immobilized men given the training program, bone formation was normal and bone resorption was increased. In immobilized men treated with diphosphonate, osteoid parameters and resorption activity were decreased. In immobilized men with diphosphonate plus training, the osteoid parameters and the resorption activity were reduced but to a lesser degree than in immobilized men with diphosphonate alone. Failure of bone loss in normal immobilized subjects differed from results found in paraplegic patients. However, a decrease in mineralization rate and an increase in bone resorption activity were found in both studies. Exercise stimulated bone resorption and diphosphonate inhibited the osteoclastic activity. These data emphasize the difficulties in finding good models to stimulate spaceflight conditions on earth. Comparative studies must be done using bone biopsies to determine more precisely the effects of weightlessness on the human skeleton.
已知脊髓损伤患者的固定对骨量和骨重塑的影响类似于宇航员失重引起的骨骼变化。然而，从未在健康志愿者中使用组织形态计量学研究来探究固定的影响。20名健康男性志愿者参与了苏联的一项“120天卧床休息”实验。在卧床休息期开始前和结束时采集髂嵴骨活检芯。受试者被分为五组。五名受试者过着正常的走动生活（对照组）；三名受试者连续卧床休息120天（完全固定）；四名受试者被固定并接受受控训练计划；四名受试者被固定并接受二膦酸钾治疗（乙烷 - 1,羟基 - 1,二膦酸900毫克/天，口服）；四名受试者被固定并接受二膦酸盐加体育锻炼。使用自动和半自动图像分析系统测量骨量和骨细胞活性（成骨细胞形成和破骨细胞吸收）参数。每组的骨量保持恒定。细胞活性测量表明，在完全固定的男性中，矿化率低于对照组，类骨质参数无变化；相反，破骨细胞参数增加。在接受训练计划的固定男性中，骨形成正常且骨吸收增加。在接受二膦酸盐治疗的固定男性中，类骨质参数和吸收活性降低。在接受二膦酸盐加训练的固定男性中，类骨质参数和吸收活性降低，但程度小于仅接受二膦酸盐治疗的固定男性。正常固定受试者未出现骨质流失的情况与截瘫患者的结果不同。然而，两项研究均发现矿化率降低和骨吸收活性增加。运动刺激骨吸收，二膦酸盐抑制破骨细胞活性。这些数据强调了在地球上寻找模拟太空飞行条件的良好模型的困难。必须使用骨活检进行比较研究，以更精确地确定失重对人体骨骼的影响。
