Quantitative analysis for fatty acid amide hydrolase (FAAH) using PET with [11C]DFMC

Objective: [11C]DFMC was previously developed as a promising PET ligand for fatty acid amide hydrolase (FAAH), a key enzyme for regulation of endocannabinoid system in the central nervous system. Here, we aimed to quantify FAAH concentrations using PET with [11C]DFMC in brain regions.Method: PET assessments with blood sampling were conducted for 90 min using rats. Kinetic analyses were performed by an irreversible two-tissue compartment model (2TCMi) and Patlak graphical analysis (PGA). Results: The highest radioactive uptake of [11C]DFMC was obtained in the cingulate cortex. The kinetic parameters (λk3 and Ki) for FAAH concentrations in the cingulate cortex were 0.56 ± 0.08 and 0.19 ± 0.02 mL/cm3/min, respectively. The Ki values based on 2TCMi in all regions were similar to that of PGA, which supports that kinetic parameters based on compartment model were concisely estimated. Conclusion: We successfully obtained in vivo mapping for regional FAAH concentrations by PET with [11C]DFMC.第58回日本核医学会学術総