THE DISPOSITION OF SERUM-PROTEINS AS DRUG-CARRIERS IN MICE BEARING SARCOMA-180

The tumor distribution and the disposition of serum proteins, such as albumin, fetuin, transferrin, and IgG, were investigated in mice beari ng Sarcoma 180. Serum proteins labeled with fluoresceinisothiocyante ( FITC) we mice in order to investigate the effect of chemical modificat ion. The plasma concentration of each glutarylated serum protein was s ignificantly lower, about 15 to 46-fold, in comparison to that of the non-acylated protein at 24 h after administration. The tissue distribu tions of the glutarylated serum proteins were also decreased compared to those of the non-acylated proteins. Especially, the hepatic distrib ution of albumin and IgG was significantly reduced with glutarylation. The urinary excretion of albumin and transferrin, and fecal excretion of IgG, were significantly increased with glutarylation. The serum pr oteins were accumulated effectively in the tumor tissue in mice bearin g Sarcoma 180. It was found that the tumor distributions were not impa ired by the glutarylation, except involving fetuin. It was suggested, therefore, that the glutarylated serum proteins were valuable for rela tive tumor-selectivity and might be utilized in a macromolecular carri er system for antitumor drugs.