Iodine Contrast Medium Sensitizes Cultured Mammalian Cells to X Rays but Not to γ Rays

Abstract

The influence of an I contrast medium on several responses to radiation was examined in mammalian cells in culture (mouse lymphocytic leukemia L5178Y cells). The presence of the medium at the time of irradiation enhanced cell killing, frequency of micronuclei and yield of DNA single-strand breaks induced by X-rays depending on the concentration used. No such effect was found with .gamma. rays. The contrast medium apparently sensitizes mammalian cells in culture primarily by the photoelectric effect, increasing the absorbed dose of X-rays in the cells.