Tracer studies on cobalt incorporation into growing tumors: uptake of radioactive Co60 by normal and malignant cells.

Information on the uptake of metal trace ele ments by living tissues and on the localization of these cations within the cells is of considerable in terest, since many enzyme reactions take place only in the presence of metal activators. In particular, increasing interest has lately been aroused in the uptake of these inorganic constituents by neoplastic tissues. Work on zinc by Heath and Liquier-Milward (5) and Wormall (15) has shown that this metal is associated with the deoxyribose nucleoproteins ex tracted from tumor tissues. Since cobalt is known to be of importance in cell metabolism, through its activation of enzymes as well as through its ef fect upon growth and respiration, a study of its distribution pattern in tumor-bearing animals has been made, and tracer work with Co60 on mice