Functional imaging of pharmacological action of SGLT2 inhibitor ipragliflozin via PET imaging using C-MDG.

Sodium-dependent glucose cotransporter 2 (SGLT2) is a pharmacological target of type 2 diabetes mellitus. The aim of this study was to noninvasively visualize the pharmacological action of a selective SGLT2 inhibitor ipragliflozin in the kidney using positron emission tomography (PET) imaging with C-methyl-d-glucoside (C-MDG), an SGLT-specific radio-labeled substrate. PET imaging with C-MDG in vehicle-treated rats demonstrated that intravenously injected C-MDG substantially accumulated in the renal cortex, reflecting that the compound was reabsorbed by SGLTs. In contrast, ipragliflozin-treated rats showed significantly lower uptake of C-MDG in renal cortex in a dose-related manner, suggesting that ipragliflozin inhibited the renal reabsorption of C-MDG. This method of visualizing the mode of action of an SGLT2 inhibitor in vivo has demonstrated the drug's mechanism in reducing renal glucose reabsorption in kidney in living animals.