抄録
On the basis of some results of our experiments, the recent progress in biological research of aging mechanism in multi-cellular organism is reviewed. Comparison of the life span of various organisms of different phyla indicates/that definite length of the life span is found in animals supported by the post-mitotic critical cells. In mouse and fish, age related changes in DNA structure in the post mitotic cells were demonstrated in vitro by templete activity of DNA of cells at different ages. In old cultured chick fibroblasts, cell surface was coated with hyaluronic acid. From various facts, important role of extracellular compartments in aging of organism is also suggested.