The effect of burn on L-glucose permeability

Objectives: Alterations in tissue permeability due to inflammation results in non-specific increases in accumulation of tracers at these sites. L-Glucose is not a substrate for either glucose carrier proteins, glucose receptors and hexokinase; therefore, cellular penetration is negregable. Thus, an F-18 labeled L-glucose analog may be useful in identifying inflammation sites using PET imaging. In this report, we prepared 2-[¹⁸F]fluoro-2-deoxy-L-glucose and studied its localization following burn injury.

Methods: 2-[¹⁸F]fluoro-2-deoxy-L-glucose was prepared from the L-mannose triflate in a manner similar to that for 2-FDG production. Focal sites of inflammation were produced in mice by thermal injury. The dorsal and/or ventral surfaces were exposed to hot water for 9 seconds. Animals were injected with ~ 0.7 mCi tracer and imaged dynamically for 30 min using a Siemens P4 microPET. After rebinning in 2 min frames the images were reconstructed and regions of interest were placed over the inflammatory sites and the contralateral uninvolved area. The animals were euthanized and the biodistristribution of the tracer determined one hour after sacrifice.

Results: The L-glucose rapidly entered inflammatory sites of the skin surrounding the burn injury and several other tissues at 24 hrs post injury. Seven days after injury, the L-glucose continued to show leakiness in the non-injured skin surrounding the burn injury and several tissues including the gut, while other tissues had resolved to a normal state similar to shams. The biodistristribution data was confirmed by PET imaging. In injured tissues, peak uptake occurred at an hour after tracer injection, while the tracer was washed-out rapidly in normal tissue beginning at ~3-4 min after injection. Conclusion: The rapid uptake of 2-[¹⁸F]fluoro-2-deoxy-L-glucose is attributed to increased tissue permeability. These results demonstrate the feasibility of using 2-[¹⁸F]fluoro-2-deoxy-L-glucose for imaging of increased permeability after burn injury which induces inflammation.