Diamide: A New Radiosensitizer for Anoxic Cells

Abstract

in P. fluorescens: anoxic cells are sensitized by diamide, whereas the survival of euoxic cells is unaffected by it. Sensitization of anoxic mammalian cells by diamide is unique in that the reagent causes only a small decrease in Do (approximately 30%) but completely removes the shoulder of the survival curve-i.e., the extrapolation number is reduced to one. Preliminary results indicate that a combination of diamide and the slope-modifying compound, nifuroxime, sensitizes anoxic V79 cells better than either compound alone and, in fact, better than oxygen. The results are discussed in relation to the role of endogenous nonprotein sulfhydryl in radiation sensitivity and to the possible use of diamide as a radiosensitizer for anoxic