Distribution of 46Sc and 51Cr in tumor-bearing animals and the mechanism for accumulation in tumor and liver.

Tumor uptake rates, concentrations in mitochondrial fraction (containing lysosome) of liver and tumors, avid accumulations in connective tissue (especially inflammatory tissue) and binding substances in these tissues for 46Sc3+ and 51Cr3+ were essentially similar to those for 67Ga3+, 111In3+, 169Yb3+, 167Tm3+, 95Zr4+ and 181Hf4+. However, the main binding substance of 46Sc3+ and 51Cr3+ in tumor and liver was the acid mucopolysaccharide (as described concerning 95Zr and 181Hf) whose molecular weight exceeded 40,000, although the main binding substance of 67Ga3+, 111In3+, 169Yb3+ and 167Tm3+ was the acid mucopolysaccharide with a molecular weight of about 10,000.