Synthesis and evaluation of Ga labeled palmitic acid for cardiac metabolic imaging.

This work evaluates the potential of a Ga labeled long chain 16C fatty acid for cardiac metabolic imaging. For radiolabeling with Ga, hexadecanedioic acid was coupled with the chelator p-NH-Bn-NOTA. Under the optimized conditions, NOTA-hexadecanoic acid could be radiolabeled with Ga in ≥95% yields. In biodistribution studies carried out in Swiss mice, Ga-NOTA-hexadecanoic acid showed low myocardial uptake at 2 min p.i. (3.7 ± 1.3%ID/g). While Ga-NOTA-hexadecanoic acid cleared rapidly from non-target organs such as blood, lungs, intestine and kidney, wash out from liver was slow. Radio-HPLC analyses of myocardial extracts of rats injected with Ga-NOTA-hexadecanoic acid confirmed its metabolic transformation in the myocardium.