[en] The subcellular distribution and lipid analysis studies of the 3-monomethyl-branched (BMIPP), 3,3-dimethyl-branched (DMIPP), and the parent straight-chain 15-para-iodophenylpentadecanoic acid (IPP) are described. Because of the observed differences of the relative myocardial uptake and retention of these agents in fasted and nonfasted rats, a detailed evaluation of the subcellular distribution profiles and the distribution of radioactivity within various lipid pools extracted from cell components was performed. The dimethyl DMIPP analogue showed the longest retention and also showed the highest association with the mitochondrial and microsomal fractions. The 3-monomethyl (BMIPP) analogue appeared to undergo slower oxidation than the straight chain (IPP), and the dimethyl-branched (DMIPP) analogue was apparently not oxidized by the myocardium. All three analogues showed some incorporation into triglycerides. Because the positron emitting radioisotopes of bromine show good radionuclidic properties, a new [⁸²Br]-labeled bromopentenyl-substituted cation was prepared. The tissue distribution of triphenyl-(E,Z-[⁸²Br]bromopenten-5-yl)phosphonium iodide in rats showed high heart uptake and retention with high heart to blood ratios. Radioiodinated (E)-2-C-iodovinyl-D-glucose has been prepared as a new iodovinyl-substituted carbohydrate containing C-iodovinyl-branching at the 2-position. 5 refs., 11 figs., 2 tabs