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.
The purpose of this study was to compare by planar myocardial scintigraphy the kinetics of iodine-123-15-(iodophenyl)pentadecanoic acid (123I-pPPA and 123I-oPPA), and of iodine-123-(p-iodophenyl)-3-R,S-methyl-pentadecanoic acid (BMIPP), firstly in normal baboons, and subsequently after blocking fatty acid oxidation by a carnitine palmitoyl transferase I(CPT1) inhibitor. The induced changes in myocardial metabolism were reflected in the dynamic behaviour of the three tracers. pPPA and oPPA to a large extent, provided information on beta-oxidation changes in the myocardium: beta-oxidation participation changed from 47% and 50%, respectively to 17% and 23% after inhibition. BMIPP provided better images and reflected largely on changed tracer incorporation into the neutral lipid pools. The beta-oxidation contributed only about 10% towards the metabolic pathway of BMIPP. The information obtained in this study could help determine the tracer of choice for SPECT, whereby myocardial viability could optimally be revealed.
Institute for Life Sciences, University of Pretoria, South Africa.
I C
IC
Dormehl
N
N
Hugo
D
D
Rossouw
A
A
White
L E
LE
Feinendegen
D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000037:antagonists & inhibitors; D003652:Decanoic Acids / Q000493:pharmacokinetics*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004852:Epoxy Compounds / Q000494:pharmacology; D005227:Fatty Acids / Q000378:metabolism; D006321:Heart / Q000000981:diagnostic imaging* / Q000187:drug effects; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007457:Iodine Radioisotopes; D007462:Iodobenzenes / Q000493:pharmacokinetics*; D008099:Liver / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D010215:Papio; D013329:Structure-Activity Relationship; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
D003652:Decanoic Acids; D004791:Enzyme Inhibitors; D004852:Epoxy Compounds; D005227:Fatty Acids; D007004:Hypoglycemic Agents; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; C049338:iodofiltic acid; C025391:omega-(4-iodophenyl)pentadecanoic acid; D002334:Carnitine O-Palmitoyltransferase; C054207:etomoxir