title: Caffeine enhancement of radiation killing in different strains of Saccharomyces cerevisiae.
abstract: Haploid and diploid wild type strains, and three classes of radiation-sensitive mutants of Saccharomyces cerevisiae were tested for enhancement of UV-inactivation by caffeine in growth medium. In addition, the sensitizing effect of caffeine was studied in a haploid and a diploid wild type strain after gamma-irradiation. The drug sensitized the UV-irradiated cells of all strains except those reported to be only slightly UV-sensitive but highly sensitive to ionizing radiation. After gamma-irradiation, no caffeine-enhancement of killing was observed in stationary phase cells of either the haploid or the diploid strain. However, log-phase cells of both strains were partially sensitized. The results of both sets of experiments suggested that caffeine interferes with a recombinational repair occurring in cells in S or G2 phase.
mesh_terms: D002110:Caffeine / Q000494:pharmacology*; D002453:Cell Cycle; D004260:DNA Repair / Q000187:drug effects*; D005720:Gamma Rays; D011003:Ploidies; D011995:Recombination, Genetic / Q000187:drug effects*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D002110:Caffeine