Iodinated Bleomycin: An Unsatisfactory Radiopharmaceutical for Tumor Localization.
ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD
Pagination or Media Count:
Cobalt-57 bleomycin is a clinically useful tumor localizing agent, but attempts to label bleomycin BLEO with other radionuclides have been made because of the long physical half-life of Co57. As an alternative labeling approach, BLEO was iodinated both directly on the imidazole ring and indirectly by reaction with N-succinimidyl 3-4-hydroxy, 3-iodophenyl propionate. Directly iodinated BLEO retained antibacterial activity, but in tumor-bearing rats showed a lower tumor to blood ratio at 2 hours 2.3 than was obtained with Co57 BLEO 11.8. The antibacterial activity of the indirectly labeled BLEO was markedly reduced and this material showed a tumor to blood ratio at 2 hours of 0.55.
- Medicine and Medical Research