Pancreas accumulation of radioiodinated HIPDM in mice and rats

High pancreatic affinity for 131I-labeled HIPDM was observed in mice and rats. Although the brain uptake of [131I]HIPDM is very fast, the pancreatic uptake is rather slow. The pancreas to liver ratios (per gram) were 5.08 +/- 0.52 in mice and 5.15 +/- 0.65 in rats at 2 hr and 7.05 +/- 0.53 in mice and 8.06 +/- 1.14 in rats at 5 hr after administration. These ratios are higher than those obtained with routinely used pancreatic agent [75Se]selenomethionine. An increase in liver uptake and decrease in pancreatic uptake was observed at higher dose of carrier HIPDM, which resulted in lower pancreas to liver ratios. HIPDM is a new type of compound which shows predilection for pancreas. Our results suggest that [123I]HIPDM might be a useful agent for pancreas imaging.