title: Radioiodinated branched-chain fatty acids: substrates for beta oxidation? Concise communication.
abstract: Branched-chain iodinated fatty acids have been proposed for use as myocardial imaging agents. Several omega- iodoalkyl and omega- iodoaryl beta-methyl branched fatty acids have been synthesized and tested in rats. Myocardial activity levels at t = 5 min are affected by chain length for both alkyl and aryl acids, with chain lengths of 16 carbons possessing higher levels of activity than shorter lengths. Branching significantly lowers heart-to-blood ratios relative to straight-chain analogs. The degree of branching also affects radioactivity levels. Monoalkylation at the beta-carbon does not reduce the levels for omega- iodoalkyl fatty acids, but dialkylation reduces the levels significantly. Branching in the omega- iodoaryl series of fatty acids altered the time course of activity in the myocardium from a level of activity decreasing with time for the straight-chain acid to an essentially constant level of activity for the branched analogs.
mesh_terms: D000818:Animals; D005227:Fatty Acids / Q000138:chemical synthesis / Q000378:metabolism*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism*; D010084:Oxidation-Reduction; D011877:Radionuclide Imaging; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship
chemical_list: D005227:Fatty Acids; D007457:Iodine Radioisotopes