Abstract
Objectives: This study was designed to investigate the capability of a small-animal SPECT imager, FastSPECT II, for dynamic rat heart imaging and to characterize the in vivo kinetic properties of 99mTc-C2A-glutathione-s-transferase (GST), a molecular probe targeting apoptosis and necrosis, in detecting cell death in ischemic-reperfused rat hearts. Methods: C2A-GST was radiolabeled with 99mTc via 2-iminothiolane thiolation. Myocardial ischemia-reperfusion was induced by 30-min ligation of the left coronary artery followed by 120-min reperfusion in seven rats. FastSPECT II cardiac images of 99mTc-C2A-GST in list-mode acquisition were recorded for 2 h using FastSPECT II. Results: Tomographic images showed a focal radioactive accumulation (hot spot) in the lateral and anterior walls of the left ventricle. The hot spot was initially visualized 10 min after injection and persisted on the 2-h images. Quantitative analysis demonstrated that the hot-spot radioactivity increased significantly within 30 min postinjection and experienced no washout up to the end of the 2-h study. The ratio of the hot spot/viable myocardium was 4.52±0.24, and infarct-to-lung ratio was 8.22±0.63 at 2 h postinjection. The uptake of 99mTc-C2A-GST in the infarcted myocardium was confirmed by triphenyl tetrazolium chloride staining and autoradiography analysis. Conclusions: FastSPECT II allows quantitative dynamic imaging and functional determination of radiotracer kinetics in rat hearts. An in vivo kinetic profile of 99mTc-C2A-GST in the ischemic-reperfused rat heart model was characterized successfully. The pattern of accelerated 99mTc-C2A-GST uptake in the ischemic area at risk after reperfusion may be useful in detecting and quantifying ongoing myocardial cell loss induced by ischemia-reperfusion.
Original language | English (US) |
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Pages (from-to) | 907-915 |
Number of pages | 9 |
Journal | Nuclear Medicine and Biology |
Volume | 34 |
Issue number | 8 |
DOIs | |
State | Published - Nov 2007 |
Funding
The authors wish to acknowledge the technical support of Christy Barber and the editorial assistance of Corrie Thies. This work was supported by NIH Grant P41 EB002035 and an American Heart Association grant.
Keywords
- Apoptosis
- C2A
- Heart
- Necrosis
- Rat
- SPECT
ASJC Scopus subject areas
- Molecular Medicine
- Radiology Nuclear Medicine and imaging
- Cancer Research