[Potential application of DTPA for improving the image quality in radioimmunoscintigraphy with 111In labeled monoclonal antibodies].
Studies on application of diethylenetriamine-pentaacetic acid (DTPA) to decrease the non-specific localization of 111In-labeled antibodies (111In-MoAb) to the liver were performed. The transchelation of 111In to the molecule of M.W. 70,000-90,000 by the incubation of 111In-MoAb in human serum was inhibited by adding DTPA. These in vitro findings were also demonstrated by serum analysis after 111In-MoAb injection to the normal mice and postinjection of DTPA. By addition of DTPA, the uptake of 111In-MoAb by isolated rat hepatocytes was inhibited, but the 111In-release was unaffected. The addition of DTPA had no effect on uptake of 111In-MoAb and 111In-release in tumor cells. These results suggest that DTPA administration following 111In-MoAb injection may inhibit transchelation of 111In to transferrin or other serum proteins, so decrease non-specific liver localization of 111In and give rapid blood clearance.
Ochi
K
K
Department of Radiology, Ehime University School of Medicine.
Fujii
T
T
Kimura
Y
Y
Akamune
A
A
Hamamoto
K
K
D000818:Animals; D007205:Indium Radioisotopes / Q000378:metabolism; D008099:Liver / Q000000981:diagnostic imaging* / Q000378:metabolism; D008297:Male; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D004369:Pentetic Acid / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D016719:Radioimmunodetection; D051381:Rats; D011919:Rats, Inbred Strains; D014168:Transferrin / Q000378:metabolism
D007205:Indium Radioisotopes; D014168:Transferrin; D004369:Pentetic Acid