Mikko I. Kettunen1, Brett W.C Kennedy1, De-En Hu2, Kevin M. Brindle2
1Department of Biochemistry, University of Cambridge & Cancer Research UK Cambridge Research Institute, Cambridge, Cambridgeshire, United Kingdom; 2Department of Biochemistry, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom
We have investigated whether the increase in the echo/FID ratio in a spin echo experiment, where the FID is the signal acquired immediately following the excitation pulse, could report on [1-13C]lactate and [1-13C]pyruvate transport into the tumor cells in vivo. Apparent diffusion coefficients and T2 relaxation times of these metabolites were also measured. Inhibition of the monocarboxylate transporters decreased the echo/FID ratio to some extent, showing that some of the increase was due to transport, however, under the signal acquisition conditions employed, most of the increase was due to movement of metabolites between the vascular and interstitial pools.