Abstract

Histomorphometric and biomechanical changes in bone resulting from hypogravity (simulated weightlessness) were examined in this study. Using a head-down hindlimb suspension model, three groups of six male rats underwent simulated weightlessness for periods of one, two and three weeks while a fourth recovery group was suspended for weeks followed by two weeks of normal activity. Biomechanical data were collected during static and dynamic bending and torsion tests in intact femora. Histomorphometric values were determined from midshaft bone cross sections and material properties were material properties than the controls, resulting in structural hypotrophy; geometric and material changes contributed equally to the structural changes. Recovery following a return to normal activity was indicated, although full recovery may take longer than the weightlessness period. In the rat, altered maturation and reduction bone strength were the sequelae of weightlessness. Verf.-Referat