Studies on the Metabolism of Nuclear Basic Proteins After Radiation In Vitro

Abstract

Exposure of isolated rabbit lymphocytes to 1000 R γ-radiation results in an increased rate of incorporation of amino acids-14C into cellular proteins during the first hour after irradiation. Fractionation of the proteins showed that the synthesis of basic proteins extracted from the nucleus was most affected. Two factors contributed to this apparent stimulation of protein synthesis by irradiation: (a) a transient increase in the amount of amino acid-14C available for protein synthesis in the cell; and (b) an increase in concentration of sodium ions in the cell. It is suggested that much of the observed increase in amino acid incorporation after irradiation of the lymphocytes is caused by radiation-induced changes in cell permeability.