Abstract 16539: Visualization and Quantification of FDG Uptake in Myocardium of CD36-Knockout Mice in vivo Using a Novel High Spatial Resolution Semiconductor PET
Background: Cardiomyocytes utilize glucose and free fatty acids as an energy source. The disproportional utilization of these substrates was reported to cause cardiac malfunctions. However, the reason for this has not been clarified. Thus, it is crucial to investigate in vivo the energy substrate utilizations in the heart of animal models. CD36 is an important transporter of long-chain fatty acids (LCFA) in the myocardium. As we reported, CD36-deficient patients are often accompanied by cardiomyopathy and demonstrate a marked reduction of myocardial uptake of BMIPP, an analogue of LCFA, while myocardial uptake of FDG is increased.
Objectives: To investigate in vivo the myocardial FDG uptake in CD36KO mice with a novel high spatial resolution semiconductor PET.
Methods: 18F-FDG was injected into CD36-knockout (KO) and wild type (WT) mice (both, n=7) in fasting state. PET was performed 1 h after injection with semiconductor PET (MIP-100, Sumitomo Heavy Industries, Tokyo). The spatial resolutions in transaxial and axial directions were less than 0.7 mm and 0.8 mm FWHM, respectively, at the center. MRI examination was performed in all mice with the same holder for PET/MRI fused image. Three-dimensional region of interest was drawn on myocardium of PET images for semi-quantitative analysis of standardized uptake value (SUV).
Results: Myocardial FDG uptake in the myocardium of right and left ventricle was clearly visualized (Figure) and substantially increased in KO mice on visual analysis. Semi-quantitative analysis exhibited a significantly higher myocardial uptake of FDG in KO than in WT mice (SUVmean=10.8±2.2 and 6.2±3.0, respectively, p<0.01). Glucose metabolism in myocardium of KO mice was significantly increased as compared with WT, reflecting the compensation for decreased fatty acid uptake.
Conclusion: We could clearly visualize in vivo the enhanced myocardial uptake of FDG in CD36-KO compared with WT mice, using high spatial resolution semiconductor PET.
- © 2010 by American Heart Association, Inc.