Influence of oxic and extremely hypoxic conditions on the recovery of sublethal radiation damages in small multicellular spheroids of Chinese hamster cells

Split-dose timing curves studies for aerobic conditions of X-irradiation exhibited recovery factors of 3.0 and 11.2 for Chinese hamster cells irradiated in suspension and in the association as spheroids, respectively. The recovery factor was reduced to 2.6 if the irradiation of cells associated to spheroids and the incubation between the divided doses were performed under extremely hypoxic conditions. Repair of sublethal damages could not be improved, if the two single doses were applied in hypoxia but the incubation between the two fractions was performed in air atmosphere. (author)