X-radiation Inhibition of the Induction of Kidney Enzymes catalysing Synthesis of Deoxyribonucleic Acid in vitro

Abstract

IT is generally conceded that damage induced by exposure to ionizing radiation causes alterations in the metabolism of deoxyribonucleic acid (DNA) in the irradiated cell^1,2. However, no agreement exists at the present time concerning the exact locus of this radiation-sensitive component(s) in the metabolic chain of DNA synthesis. Two of us (E. R. W. and R. K. M.)³ have shown that exposure of an in vitro enzymatic system for DNA synthesis, derived from rat thymus, to doses ranging from 250 to 10,000 rads X-radiation during the first 40 min. of a 5-hr, incubation period produced no measurable inhibitory effect on DNA synthesis. Thus, the kinases and poly-merases per se are not radiosensitive.