Uptake of 18F-labeled 6-fluoro-6-deoxy-D-glucose by skeletal muscle is responsive to insulin stimulation.

Unlabelled: We are developing a methodology for the noninvasive imaging of glucose transport in vivo with PET and (18)F-labeled 6-fluoro-6-deoxy-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 (18)F-6FDG was negligible in several tissues.

Conclusion: (18)F-6FDG is a valid tracer that can be used in in vivo transport studies. PET studies performed under glucose clamp conditions demonstrated that the uptake of nonphosphorylated glucose transport tracer (18)F-6FDG is sensitive to insulin stimulation.