Biological effects of space radiation.
To determine the effects of space radiation on human health for long-term stays in space, we performed 21 space experiments on radiation biology. Two main characteristics of space are microgravity and space radiation that consists of low dose, chronic exposure at low dose-rates, and heavy particles. Through space experiments, we demonstrated the formation of DNA strand breaks, induced mutations, abnormal cell differentiation and the inducible gene expression of a tumor suppressor gene product, p53, in various kinds of organisms. In addition, we investigated the influence of microgravity on radiation-induced biological effects in in vitro biochemical reaction systems and in vivo cell culture systems of bacteria and lower eukaryotes. We review here the importance of radiation biology studies on space radiation from the viewpoints of human health and biological evolution, from the beginning of life until today, in the context of environmental genotoxic radiation.
Ohnishi
T
T
Department of Biology, Nara Medical University, Nara, Japan. tohnishi@naramed-u.ac.jp
Takahashi
A
A
Ohnishi
K
K
D000337:Aerospace Medicine; D000818:Animals; D001419:Bacteria / Q000528:radiation effects; D003359:Cosmic Radiation; D004249:DNA Damage; D004260:DNA Repair; D004307:Dose-Response Relationship, Radiation; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism / Q000528:radiation effects; D006801:Humans; D012062:Relative Biological Effectiveness; D013026:Space Flight; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism / Q000528:radiation effects; D014893:Weightlessness
D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D016159:Tumor Suppressor Protein p53