Nuclear Medicine Program progress report, quarter ending March 31, 1992

We describe the design synthesis and initial animal testing of a new iodine-131-labeled triglyceride analogue for the potential evaluation of clinical pancreatic insufficiency. The new agent is 1,2-dipalmitoyl-3-((15-p-iodophenyl)pentadecanoyl) rac-glycerol(1,2-Pal-3-IPPA). Following oral administration of the iodine-125-labeled agent to rats, 34.5+8.8% of the administered activity was excreted in the urine within one day, demonstrating that radioiodinated IPPA is absorbed in the intestine after release from the triglyceride by pancreatic lipase. The final catabolic product of IPPA is then conjugated and excreted via the urinary bladder. Urine analysis following oral administration of this new agent to patients may thus be a new, simple method for the clinical evaluation of various gastrointestinal diseases. The synthesis and the initial biological evaluation of the 3R-isomer of ({sup 125}I)IQNP are also described.