Stimulating Effect of Mercuric Chloride and Nickel Sulfate on DNA Synthesis of Thymocytes and Peripheral Lymphoid Cells from Newborn Guinea Pigs

The metal allergens mercuric chloride and nickel sulfate were found to stimulate DNA synthesis of different in vitro cultured lymphoid cells from newborn guinea pigs. In contrast to earlier findings in adult animals (where spleen cells were most consistently stimulated), in newborn animals thymocytes were the most clearly stimulated lymphoid cells. When separating thymocytes by peanut agglutinin agglutination, both agglutinated and nonagglutinated cells were stimulated, indicating that both functionally immature and mature thymocytes are the target cells for this effect of metal allergens.