Evaluation of s-1 Receptor Radioligand 18F-FTC-146 in Rats and Squirrel Monkeys Using PET

The noninvasive imaging of s-1 receptors (S1Rs) could provide insight into their role in different diseases and lead to novel di-agnostic/treatment strategies. The main objective of this study was to assess the S1R radiotracer 18F-FTC-146 in rats. Prelimi-nary squirrel monkey imaging and human serum/liver microsome studies were performed to gain information about the potential of 18F-FTC-146 for eventual clinical translation. Methods: The dis-tribution and stability of 18F-FTC-146 in rats were assessed via PET/CT, autoradiography, g counting, and high-performance liquid chromatography (HPLC). Preliminary PET/MRI of squirrel monkey brain was conducted along with HPLC assessment of 18F-FTC-146 stability in monkey plasma and human serum. Results: Bio-distribution studies showed that 18F-FTC-146 accumulated in S1R-rich rat organs, including the lungs, pancreas, spleen, and brain. Pretreatment with known S1R compounds, haloperidol, o