Planar myocardial imaging in the baboon model with iodine-123-15-(iodophenyl)pentadecanoic acid (IPPA) and iodine-123-15-(P-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP), using time-activity curves for evaluation of metabolism

Cysteine Derivatized 99mTc-Labelled Fatty Acids as β-Oxidation Markers

“…Upon coordination, downfield shifts of 0.8 ppm were noted in all complexes for the H-7 alpha-proton of cysteine, while coordination did not significantly affect the chemical shifts of the H-6 beta-protons, as previously noted in other cysteine complexes with the tricarbonyl core [46]. In the 13 C spectra, downfield shifts were noted upon coordination for the cysteine C-7 alpha-carbon by 4.0-4.7 ppm, and the C-8 carboxylate carbon by approximately 8.5 ppm, while smaller downfield shifts were noted for the cysteine C-6 beta-carbon (1-3 ppm) and the C-5 carbon adjacent to the cysteine sulphur (0.5-1.5 ppm). In addition, upon coordination the amine protons of cysteine that were invisible in the spectra of the ligands, became visible appearing as two distinct broad peaks at approximately 6.1 ppm and 4.9 ppm, the great chemical shift separation apparently reflecting the asymmetry of the complexes.…”

“…NMR spectra of all ligands and rhenium complexes were obtained in DMSO-d 6 , at 25 • C and assignment was affected through the combined analysis of 1 H-1 H and 1 H- 13 C correlation spectra ( Figures S1-S6). The full 1 H and 13 C assignments appear in Tables 1 and 2 while the numbering of the atoms is given in Scheme 3.…”

“…However, due to the rapid washout, quantification of β-oxidation was not possible and image quality was poor. This led to the development of branched-chain analogues of IPPA (Scheme 1), such as the 123 I-beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) [13][14][15] which only partially undergoes β-oxidation and is mainly retained in the triglyceride pool. Thus, retention time is increased and image quality is vastly improved [10] rendering BMIPP the radiopharmaceutical of choice for the assessment of cardiac β-oxidation.…”

Metabolic Imaging for Identifying Antecedent Myocardial Ischemia and Acute Coronary Syndrome in the Emergency Department

“…In subsequent occlusion-reperfusion studies in canines, prolonged metabolic alteration was shown after 30 min of coronary occlusion that persisted for several weeks thereafter [17]. These studies served as the experimental basis of subsequent clinical studies in which persistent reductions in fatty acid metabolism were shown long after the resolution of the perfusion abnormality and ischemia, a phenomenon that has been referred to as "ischemic memory" [4,5,[18][19][20]. Thus, the application of a metabolic radiotracer for imaging, as opposed to a perfusion tracer, potentially extends the scope for noninvasive imaging of an ischemic event beyond the resolution of symptoms.…”

Targeted Metabolic Imaging to Improve the Management of Heart Disease

“…In subsequent occlusion-reperfusion studies, prolonged metabolic alterations were observed after 30 minutes of occlusion. These metabolic changes persisted for several weeks thereafter (48–51). The studies served as the experimental basis of subsequent clinical studies in which persistent reductions in fatty acid metabolism could be detected long after the resolution of the perfusion abnormality and ischemia (52–58).…”