D-Glucose by Skeletal Muscle Is Responsive to Insulin Stimulation

We are developing a methodology for the noninvasive imaging of glucose transport in vivo with PET and 18 F-labeled 6-fluoro-6deoxy-D-glucose ( 18 F-6FDG), a tracer that is transported but not phosphorylated. To validate the method, we evaluated the biodistribution of 18 F-6FDG to test whether it is consistent with the known properties of glucose transport, particularly with regard to insulin stimulation of glucose transport. Methods: Under glucose clamp conditions, rats were imaged at the baseline and under conditions of hyperinsulinemia. Results: The images showed that the radioactivity concentration in skeletal muscle was higher in the presence of insulin than at the baseline. We also found evidence that the metabolism of 18F-6FDG was negligible in several tissues. Conclusion: 18 F-6FDG is a valid tracer