The Restoration of Hemolysin Formation in X-Rayed Rabbits by Nucleic Acid Derivatives and Antagonists of Nucleic Acid Synthesis

Abstract

Restoration of hemolysin-producing capacity was tested in rabbits 24 hours after administration of 400 r hard X-rays at the approximate low point in their hemolysin-producing capacity. The test materials were mixed with the antigen, i.e., sheep red cells, or were injected immediately after the antigen. They were injected intravenously except for colchicine and croton oil which were given subcutaneously. Whereas X-rays decreased peak titer and the rate of rise of antibody and increased the length of the induction period, effective test materials restored peak titer and the rate of rise to within normal limits, but did not alter the lengthened induction period. By these criteria, colchicine and yeast were restorative; 3-indoleacetic acid, kinetin and preparations of DNA and RNA enzymatically degraded in vitro by their specific nucleases were partially restorative; and the polymerized nucleic acids, adenine, the nucleosides, the nucleotides, and croton oil (which was used as a control for colchicine) were ineffective. In addition, colchicine and, to a less extent, yeast increased the hemolysin response in normal nonirradiated rabbits. These results are discussed with respect to nucleic acid metabolism and the initiation of the immune response.