F-18-FDG transport: Dependence on glucose concentration

The aim of the study was to demonstrate the influence of glucose concentrat ion on the uptake of F-18-FDG in tumor cells in a simple experimental model . Glioblastoma cells in culture were incubated with F-18-FDG in presence of different glucose concentrations in the range of 0-10 mmol/L. With a const ant F-18-FDG concentration of 0.05 mmol/L we observed a linear F-18-FDG upt ake within an incubation time of 20 minutes. A stepwise increase of glucose concentrations from 0.00001-10 mmol/L resulted in a slight activation at 0 .010 mmol/L and an increasing inhibition of FDG uptake with concentrations higher than 0.05 mmol/L glucose. These results explain the improved uptake of F-18-FDG in fasting persons. They also prove that PET can be used for bi ochemical investigations.