摘要
The complex environment in space,including microgravity,radiation,and ultradian rhythms[1],may injure human health during long-term travel.The bone loss induced by space travel is one of the main reasons that limited the development of the manned space program.However,besides microgravity,ionizing radiation such as the solar particle events(SPE),galactic cosmic radiation(GCR)and Earth’s radiation belts(ERBs)which mainly consist of electrons,protons and heavy ions make the exposure of astronauts to high dose of radiation unavoidable not only in a space station but also in deep space exploration[2].Previous studies suggest that microgravity has the most profound effect on human skeletal system.Although bone loss associated with microgravity has been well characterized[3],there are no reports concerning the combined effects of microgravity,ionizing radiation exposure and ultradian rhythms on bone loss.Here,we used the hindlimb suspension model followed by ionizing radiation exposure and ultradian rhythms to investigate the effects of space environment factors on skeletal system.
