Increase in the Dense Cytoplasmic Bodies in Radiation-induced Giant Cells of the Cultured Fibroblast

Abstract

THE formation of giant cells after the irradiation of cell cultures was described by Puck and Marcus¹ in HeLa cells. The phenomenon also occurs in cultured fibroblasts. After a dose of 1,000 r., a high percentage of the cells in the cultures cease to undergo mitosis but continue to grow in bulk, forming characteristic giant cells which survive for about two weeks under normal culture conditions. Dickson, Paul and Davidson² have shown that the giant cells contain twice the deoxyribonucleic acid, ribonucleic acid, protein and lipid of the normal cell and that the synthesis of these compounds appears to be normal. The primary radiation effect, therefore, would seem to be on the mechanics of mitosis.