A Special Section: The Radioadaptive Response

Abstract

PREFACE
Dr. Sheldon Wolf and his colleagues in the USA proposed the use of the term "radioadaptive response" about 1980. A priming irradiation with a low dose or delivered at a low dose rate was observed to depress the biological effects induced by a subsequent high dose irradiation. This phenomenon had already been observed after exposures to UV light and to heat. UV-reactivation had been described, and this meant that UV-irradiated phage had higher survival rates in Escherichia coli host cells which had been irradiated with a low dose of UV light prior to infection. Lower survival rates were seen for phage in host cells which had not been exposed to UV prior to infection. In the case of heat, cells exposed to a mild heat treatment acquired thermotolerance against subsequent severe heat exposures. The development of this thermotolerance was shown to depend on the induction of heat shock proteins. Therefore, when the first reports of the radioadaptive response were made, scientists were already aware of such a phenomenon. In addition, this adaptive behavior can be considered quite similar to the immune response which is initiated by a weak exposure to an antigen.
Organisms on the earth exist and adapt to environmental changes through the aid of many types of biological functions. There is currently no answer to the question of whether many different organisms can adapt and survive by using the same adaptive mechanisms. However, this is a very interesting area for science to focus on. In this special issue, recent papers are presented discussing the radioadaptive response. These papers were presented in a workshop at the annual meeting of the Japanese Radiation Research Society (Dr. T. Norimura, president) in Kitakyushu City in November, 2008. I hope these manuscripts will provide useful and helpful information for those interested in current and future progress in the study of the radioadaptive response.

Translated and modified from Radiat. Biol. Res. Comm. Vol.43(4); 408, (2008, in Japanese).