Tumor detection by radioimaging of hepatic radiozinc—Correlation with metallothionein content

Abstract

In order to determine if the radioimaging of the level of hepatic metallothionein (MT) is able to detect malignancy, we performed, using 65Zn, a trial to measure MT levels in the liver of experimental tumor-bearing mice and rats. The distribution of 65Zn in the livers of the mice and rats increased with s.c. transplantation of Ehrlich carcinoma and ascites hepatoma 7974F, respectively. A Sephadex G-75 elution profile of the cytosol fraction of the liver showed that the elevation of 67Zn level was due to elevation of the MT level. At 2 days after tumor transplantation in mice, the 65Zn-image demonstrated elevation of the hepatic MT level, while 67Ga-citrate, which is currently utilized, could not image the tumor at such an early period of growth. These results suggest that hepatic MT is a useful marker for the detection of malignancy at the early stage.