Radioiodinated 15-(p-iodophenyl)-3,3-dimethylpentadecanoic acid: a useful new agent to evaluate myocardial fatty acid uptake

Journal Article · Mon Mar 31 23:00:00 EST 1986 · J. Nucl. Med.; (United States)

OSTI ID:5206076

Knapp, Jr, F F; Goodman, M M; Callahan, A P; Kirsch, G

Radioiodinated 15-(p-iodophenyl)-3,3-dimethylpentadecanoic acid (DMIPP) has been prepared as a new terminal iodophenyl-substituted fatty acid containing dimethyl-branching at the beta position. For the synthesis of this new agent, chain homologation was accomplished by fabrication of a 2,5-disubstituted thiophene by successive Friedel-Crafts acylation and Wolff-Kishner reduction reactions, followed by thiophene ring opening. The dimethyl-branching was introduced using the monomethyl ester of dimethylglutaryl chloride. Radioiodination of the 15-phenyl-3,3-dimethylpentadecanoic acid substrate in the para position then gave DMIPP. Iodine-125-labeled DMIPP showed rapid, high myocardial uptake (min, mean % injected dose/g) in fasted rats (5, 4.67; 30, 5.06; 60, 4.79; 120, 4.37), and also exhibited good heart:blood ratios (min, heart:blood: 5, 3:1; 30, 12:1; 60, 12:1; 120, 13:1). To further evaluate the effects of dimethyl-branching, the biodistribution properties of DMIPP were compared with the 3-monomethyl-branched (15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid; BMIPP) and the unbranched (15-(p-iodophenyl)pentadecanoic acid; IPP) analogs. A triple-labeled (/sup 123/I)DMIPP/(/sup 131/I)BMIPP/(/sup 125/I)IPP mixture was administered to groups of fasted rats. These results confirmed the greater myocardial retention and higher heart:blood ratios observed with DMIPP in comparison with both the 3-monomethyl-(BMIPP) and unbranched (IPP) analogs. These data suggest that (/sup 123/3I)DMIPP is an excellent candidate for clinical evaluation of regional energy substrates (fatty acid) uptake.

• Research Organization: Oak Ridge National Lab., TN
• OSTI ID: 5206076
• Journal Information: J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 4; ISSN JNMEA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CARDIOVASCULAR SYSTEM
CHEMICAL REACTIONS
CHEMISTRY
COMPARATIVE EVALUATIONS
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DECANOIC ACID
DIGESTIVE SYSTEM
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
GLANDS
HALOGENATION
HEART
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINATION
IODINE 123
IODINE 125
IODINE 131
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
LIVER
MAMMALS
MONOCARBOXYLIC ACIDS
MUSCLES
MYOCARDIUM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIOCHEMISTRY
RADIOISOTOPE SCANNING
RADIOISOTOPES
RADIOPHARMACEUTICALS
RATS
RODENTS
TISSUE DISTRIBUTION
UPTAKE
VERTEBRATES