Synthesis and tissue distribution study of iodine-labeled benzyl- and xylylamines

Abstract
Four 125I-labeled mono- and diamines were prepared and evaluated as potential brain-imaging agents. The diamines are analogs of the previously reported 75Se-labeled diamines, which show high brain uptake and retention. All of the radioiodinated amines display high initial brain uptake in rats after i.v. injection (1.7-2.4% dose/organ). The xylylenediamines show prolonged brain retention (t1/2 [half-life] .apprxeq. 18 h), which is desirable for brain imaging. The benzylamine is rapidly cleared from brain tissue (T1/2 .apprxeq. 15 min).