Radiation research
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The radioadaptive response and the bystander effect represent important phenomena in radiobiology that have an impact on novel biological response mechanisms and risk estimates. Micromass cultures of limb bud cells provide an in vitro cellular maturation system in which the progression of cell proliferation and differentiation parallels that in vivo. This paper presents for the first time evidence for the correlation and interaction in a micromass culture system between the radioadaptive response and the bystander effect. ⋯ Further, the bystander effect was markedly decreased by pretreatment of the cells with an inhibitor to block the gap junction-mediated intercellular communication. These results indicate that the bystander effect plays an important role in both the induction of a protective effect by the conditioning dose and the detrimental effect of the challenge irradiation. Gap junction-mediated intercellular communication was suggested to be involved in the induction of the bystander effect.