Can 18F-FDG–PET show differences in myocardial metabolism between Wistar Kyoto rats and spontaneously hypertensive rats?

Positron emission tomography (PET) is useful for evaluating the cardiac metabolism of free fatty acid, glucose and oxygen both in human clinical practice and in experimental animal models. However, no data are available for such an evaluation in a model of stable compensated left ventricular hypertrophy in 14-month-old spontaneously hypertensive rats (SHRs). This study was designed to assess the metabolism of myocardial glucose in SHRs using 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) using PET. The study was performed on 14-month-old male SHRs (n = 4) and age-matched Wistar Kyoto (WKY) rats (n = 4). PET scans were performed after the administration of anaesthesia with isoflurane and injection of a bolus of 39.37 ± 3.25 (mean ± SD) MBq (1.06 mCi) of 18F-FDG. The standardized uptake value (SUV) was used to evaluate 18F-FDG uptake by the heart. The analysis of SUV showed increased metabolism in the left ventricle of SHRs compared with WKY rats. Our results show that small animal PET using 18F-FDG can be performed in 14-month-old SHRs to evaluate new therapies in the regression of left ventricular hypertrophy in SHRs because pathological myocardial metabolism in the SHR differs from the normal metabolism of the WKY rat.