Tumor and tissue distribution of 125I-labeled natural and antitumor antibodies in murine experimental tumor systems.

The binding and tissue distribution of 125I-labeled rabbit anti-sarcoma 180 (S-180) immunoglobulin G (IgG) (RAS-180G), normal rabbit IgG (NRG) and ICR mouse IgGs from normal (NMG) and S-180-bearing ICR mice (AS-180G) were studied in ICR mice bearing S-180. 125I-labelled IgGs preparted from normal (NC57G) or Adenocarconoma 755 (Ca 755)-bearing C57BL/6 mice (A755G) were also examined in C57BL/6 mice bearing ca755. Not only RAS-180G and AS-180G but also NRG and NMG persisted in the tumor site. This result suggests that allogeneic natural IgG could be used as a carrier protein for antitumor agents.