Tohoku J. Exp. Med., 2001, 194 (3)

Feasibility of Iodine-125 Labeled Anti-Human HemoglobinAntibody in the Detection of Bleeding Sites fromthe Large Bowel-A Preliminary Study

GERSON L.M. PRADO, YOSHINAO ABE, HIROSHI SAITO¹ and KAYOKO NAKAMURA²

Department of Radiology,
¹The First Department of Internal Medicine, Hirosaki University School of Medicine, Hirosaki 036-8562, and
²Department of Radiology, Keio University School of Medicine, Tokyo 160-8582

A monoclonal anti-human hemoglobin antibody that cross-reacts with mouse hemoglobin was labeled with Iodine-125 through the Chloramine-T method. The labeled antibody was used in an attempt to recognize bleeding sites from the large bowel in a mouse model, through a non-invasive enema-like study. In vitro experiments after double column chromatography of the labeled antibody and 10% trichloroacetic acid conjugation revealed that about 80% of the radioactivity was incorporated into protein. Inhibition assay containing cold (non-radiolabeled) antibody showed that Iodine-125 radiolabeled antibody preserved its immunoreactivity. Autoradiographs exquisitely demonstrated accumulation of isotope in the corresponding intestinal bleeding areas. These findings suggest that this method can be useful for scintigraphic localization of bleeding sites in the large bowel.

Keywords —— colon cancer; Iodine-125; Chloramine-T; anti-human hemoglobin antibody

© 2001 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2001, 194, 141-146

Address for reprints: Yoshinao Abe, Department of Radiology, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki 036-8652, Japan.

e-mail: abe@cc.hirosaki-u.ac.jp