Biological distribution of chemical analogs of fatty acids and long chain hydrocarbons containing a strong chelating agent.

The pharmaceutical preparation, chromatography, and biological distribution of a series of new chemical analogs of palmitic acid and diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, or diethylenetriamine are described. The biological distribution in rabbits 30 min after intravenous administration of these 99mTc-labeled and 57Co-labeled derivatives was compared to the biological distribution of the parent compound, 3H-palmitic acid. The average myocardial uptake for these compounds was 0.04%/g, compared to 0.15%/g for palmitic acid. The heart to blood ratio at 30 min reached a maximum of 3:1 for the best physiological analog of palmitic acid, compared to an average of 30:1 for palmitic acid. Although none of these analogs appears to be clinically useful, their production methods might be applicable to the synthesis of new compounds that might increase the specificity of radiopharmaceuticals.