title: 111In oxine labeled red cells for detection of simulated lower gastrointestinal bleeding in an animal model.
abstract: 111In oxine in vitro labeled red cells were evaluated in rabbits for the ability to detect gastrointestinal (GI) bleeding. A mean labeling efficiency of 81% (+/- 15.5%) was achieved. Biodistribution and translocation data demonstrated 81% of the activity within the blood pool at four hours after intravenous injection, falling to 29% by 72 hours. Peak urine excretion occurred after 60-150 minutes. Normal GI excretion was less than 1% over 72 hours. Simulated lower GE bleeding was imaged at 4, 12, and 72 hours, and amounts as small as 2 ml (1% blood volume) were seen. In rabbits the total body dose of injected 111In is 0.15 mGy/MBq (0.56 rad/mCi), and the critical organ is the spleen which received 0.49 mGy/MBq (1.82 rad/mCi). 111In oxine labeled red cells provide a sustained blood pool label without significant accumulation in the GI tract, and may have a potential use in the detection of intermitent GI bleeding in humans.
mesh_terms: D000818:Animals; D004064:Digestive System / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D004912:Erythrocytes / Q000378:metabolism*; D006471:Gastrointestinal Hemorrhage / Q000000981:diagnostic imaging*; D007204:Indium; D007553:Isotope Labeling; D011817:Rabbits; D011868:Radioisotopes; D011877:Radionuclide Imaging; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D011868:Radioisotopes; D007204:Indium