Abstract
The Effect of weightlessness on bone and muscle is one of the serious problems in long-term manned space activities. Clarification of mechanisms of adaptation of bone and muscle to gravity at both cellular and whole body levels is important not only for the development of the counter-measures for loss of bone calcium and muscle atrophy but also for the health science on the earth, particularly health problems in aged people. Simulation studies on the earth indicate that there are some local effects of gravity which may be percepted by local cells. It is hoped that the development of fundamental biology in space will promote biomedical and health sciences on the earth.
