Serial evaluation of fatty acid metabolism in rats with myocardial infarction by pinhole SPECT.
BACKGROUND
Iodine 123-labeled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) is mainly trapped in the myocardium as triglyceride, depending on the adenosine triphosphate level. Ten percent to 20% of it is metabolized through alpha-oxidation after beta-oxidation; however, the precise mechanism of the regulatory pathways of BMIPP is yet to be clarified.


RESULTS
A brief left coronary artery occlusion (10-30 minutes) was performed in 28 male Wistar-Kyoto rats. Dual single photon emission computed tomography images of BMIPP and thallium 201 were obtained 3 days and 24 days after the operation. The activities of 3-hydroxyacyl-coenzyme A dehydrogenase (HAD), citrate synthase (CS), and alpha-glycerol-phosphate dehydrogenase (GPD) were then measured in both ischemic and nonischemic regions. BMIPP and Tl-201 chloride severity scores were also evaluated conventionally. CS and HAD levels were significantly lower in the ischemic region than in the nonischemic region in the chronic group (CS, 102.9 +/- 28.1 vs 138.7 +/- 33.7 micromol/g/min, respectively, P =.0051; HAD, 54.7 +/- 20.1 vs 78.6 +/- 18.7 micromol/g/min, respectively, P =.0031). There was no difference in GPD between the ischemic and nonischemic regions. The BMIPP severity score had closer inverse relations with HAD (acute, r = -0.82; chronic, r = -0.80) and CS (acute, r = -0.87; chronic, r = -0.81), but not with GPD, than did Tl-201 chloride severity score.


CONCLUSIONS
BMIPP imaging correlates well with the activities of HAD and CS, suggesting that a decrease in BMIPP uptake reflects deterioration of both fatty acid metabolism and citrate cycle and shows information other than regional myocardial perfusion.
Hirai
T
T
Department of Cardiovascular Medicine, Graduate School of Medicine, and Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan.
Nohara
R
R
Ogoh
S
S
Chen
L G
LG
Kataoka
K
K
Li
X H
XH
Fujita
M
M
Matsumori
A
A
Taguchi
S
S
Sasayama
S
S
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism; D000818:Animals; D002950:Citrate (si)-Synthase / Q000378:metabolism; D003326:Coronary Circulation; D005227:Fatty Acids / Q000378:metabolism*; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008929:Mitochondria, Heart / Q000201:enzymology; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism*; D019275:Radiopharmaceuticals; D051381:Rats; D011921:Rats, Inbred WKY; D013318:Stroke Volume; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
D005227:Fatty Acids; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; C049338:iodofiltic acid; D005993:Glycerolphosphate Dehydrogenase; D015094:3-Hydroxyacyl CoA Dehydrogenases; D002950:Citrate (si)-Synthase