Synthesis and biodistribution of a new class of 99mTc-labeled fatty acid analogs for myocardial imaging

A series of ^99mTc-bis(aminoethanethiol)-fatty acid (^99mTc-BAT-fatty acid) analogs were synthesized and evaluated as potential tracers of myocardial metabolism. The BAT-fatty acid precursors were prepared using a new synthetic route that avoids the use of strong reducing agents such as lithium aluminum hydride. Biodistribution studies of the no-carrier-added ^99mTc-complexes were conducted in rats using ¹²⁵I]IPPA as an internal standard. The myocardial uptake of the ^99mTc-BAT-fatty acid analogs was significantly less than that of ¹²⁵I]IPPA and indicates the ^99mTc analogs are not suitable candidates for SPECT-based myocardial imaging studies.