抄録
Purpose: Heart-type fatty acid binding protein (H-FABP) is primary transporter of free fatty acid and plays an important role in myocardial metabolism, which is characterized by high specificity and rapid appearance under ischemic condition. The objective of this study was to clarify the usefulness of imaging study of targeting H-FABP appearance using radio-labeled antibody, and correlation with myocardial fatty acid metabolism and perfusion in acute reperfusion ischemia.
Method: Wistar rats were allotted to sham-operated control group (sham; n=4), ischemia non-reperfused group (IG; n=5), and ischemia-reperfusion group (RG; n=5). Ligation of left coronary artery (LCA) was performed for IG and RG. 20 min of ischemia was followed by 60 min of reperfusion for RG. 125I labeled anti H-FABP antibody (anti H-FABP), BMIPP and 99mTc-sestamibi (MIBI) was injected intravenously. Multi-tracer digital autoradiogram was performed using μ-imager®. The ratio of radioactivity in LCA related (culprit) area to the inferior (remote) area (target uptake ratio=TUR) was generated.
Results: In sham group, no visually detectable accumulation was observed for the anti H-FABP image, and TURMIBI and TURBMIPP were equivalent to 1. In IG, TURMIBI and TURBMIPP were remarkably low (0.12±0.01, 0.24±0.07). In RG, TURMIBI was significantly lower (0.20±0.03, p<0.05 vs. other groups). However, TURBMIPP was significantly higher (2.78±1.28, p<0.05) compared to the sham and IG, whereas anti H-FABP showed markedly higher ratio in the reperfused area compared to the sham and IG (3.43±0.73 vs. 0.31±0.13 and 1.09±0.07 for IG and sham; p<0.05, and <0.01, respectively).
Conclusion: Anti H-FABP accumulated specifically in reperfused area under acute ischemia, and it accorded to the area where fatty acid metabolism was activated. This study has shown the future potential for clinical application in vivo imaging of acute coronary syndrome.
