Department of Radiation Biology, University of Rochester FOUR FIGURES
Studies of potassium leakage from yeast following x-irradiation have shown a loss in the ability of the cell to retain this cation. The magnitude of this increased loss has been shown to be dose-dependent (Bair, Stannard and Bruce, '56) and also influenced by the carbon source utilized for metabolic energy during the measurement of the potassium leakage (Bruce and Stannard, '58). The ability of the cell to retain potassium appears to be in some way linked to metabolism and some alteration in this linkage occurs as a result of exposure to ionizing radiation. The defect may relate primarily to the rate of efflux from the cell, to potassium uptake or involve both. It is obviously dependent in part on the nature of the substrate. The present study attempts to relate the response of both components of this cationic exchange to alterations in the metabolic activity of the cell brought about by temperature changes. While direct correlation with specific metabolic processes is not possible by this method, general relationships can be found. These include a dear indication that the effects of irradiation on the two processes, uptake and leakage, are in opposite directions and to a degree separable.
This paper is based on work performed under contract with the United States Atomic Energy Commission at the University of Rochester Atomic Energy Project, Rochester, New York. Some of it appears in more detail in a thesis by A. K. Bruce submitted in partial fulfillment of the requirements for the Ph.D. degree,