[Space flight/bedrest immobilization and bone. Bisphosphonate and the loss of bone mineral due to space flight or prolonged bed rest].

Bone mass and strength are maintained by appropriate weight bearing. The loss of bone mineral due to space flight or prolonged bed rest has been recognized by space scientists and physicians. In spite of the wealth of knowledge obtained thus far, many questions remain unanswered regarding the mechanism of bone loss as well as the factors affecting these skeletal processes. Bisphosphonates have a potential to become countermeasures against space flight-induced or disuse osteoporosis. In this review, the effect and the possible role of biphosphonates on the prevention and treatment of unloading-induced osteoporosis are summarized and future prospects are discussed.