FURTHER STUDIES ON XANTHOPTERIN AND OTHER PTERIDINES IN BONE MARROW CULTURES

Abstract

The addition of amino acids as casein hydrolysate-plus tryptophane accelerates the rate of cell proliferation in bone marrow cultures in vitro produced by xanthopterin. Of several pteridines tested none accelerated the rate of cell proliferation as markedly as xanthopterin. Xanthopterine-7-carboxylic acid and 2-amino-4-hydroxy-7-methyl pteridine were strongly inhibitory, or have an antixanthopterin effect which is counteracted by xanthopterin.