title: An acidic extracellular environment reduces the fixation of radiation damage.
abstract: Chinese hamster ovary cells in exponential growth were irradiated with gamma or X rays in an acidic or alkaline extracellular environment. Incubation in acid medium during or after irradiation reduced the degree of fixation of potentially lethal lesions. Fixation and repair of acid-modified damage occurred with a halftime of 9 to 10 min. The rate of repair of sublethal damage was unaffected by hydrogen ion concentration and progressed with a half-time of 30 min. An acid environment modified only survival of exponentially growing cells; unfed plateau-phase cultures were unaffected.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media / Q000494:pharmacology*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays; D006863:Hydrogen-Ion Concentration; D010053:Ovary / Q000528:radiation effects*; D013997:Time Factors
chemical_list: D003470:Culture Media