@article{oai:repo.qst.go.jp:00079840,
 author = {Yamasaki, Tomoteru and Ohya, Tomoyuki and Mori, Wakana and Zhang, Yiding and Wakizaka, Hidekatsu and Nengaki, Nobuki and Fujinaga, Masayuki and Kikuchi, Tatsuya and Ming-Rong, Zhang and Tomoteru, Yamasaki and Tomoyuki, Ohya and Wakana, Mori and Zhang, Yiding and Hidekatsu, Wakizaka and Nobuki, Nengaki and Masayuki, Fujinaga and Tatsuya, Kikuchi and Zhang, Ming-Rong},
 issue = {3},
 journal = {The Journal of Pharmacology and Experimental Therapeutics},
 month = {Apr},
 note = {Fatty acid amide hydrolase (FAAH) is a key enzyme in the endocannabinoid system. N-(3,4-Dimethylisoxazol-5-yl)piperazine-4-[4-(2-fluoro-4-[11C]methylphenyl)thiazol-2-yl]-1-carboxamide ([11C]DFMC) was developed as an irreversible-type positron emission tomography (PET) ligand for FAAH. Here, we attempted to noninvasively estimate rate constant k3 as a direct index for FAAH in the rat brain. First, the two-tissue compartment model analysis including three parameters (K1–k3, 2TCMi) in PET study with [11C]DFMC was conducted, which provided 0.21 ± 0.04 mL·cm−3·min−1 of the net uptake value (Ki), an indirect index for FAAH, in the FAAH-richest region (the cingulate cortex). Subsequently, to noninvasively estimate Ki value, the reference model analysis (Patlak Reference, PGAREF) was tried using a time-activity curve of the spinal cord. In that result, the noninvasive Ki value (KREF) was concisely estimated with high correlation (r > 0.95) to Ki values based on 2TCMi. Using estimated KREF value, we tried to obtain calculated-k3 based on previously defined equations. The caluculated-k3 was successfully estimated with high correlation (r = 0.95) to direct k3 in 2TCMi. Finally, the dose relationship study using calculated-k3 demonstrated that in vivo ED50 value of URB597, a major inhibitor of FAAH, was 66.4 µg/kg in rat brain. In conclusion, we proposed the calculated-k3 as an alternative index corresponding to regional FAAH concentrations and suggested that PET with [11C]DFMC enables occupancy study for new pharmaceuticals targeting FAAH.},
 pages = {353--360},
 title = {Development of an In Vivo Method to Estimate Effective Drug Doses and Quantify Fatty Acid Amide Hydrolase in Rodent Brain using Positron Emission Tomography Tracer N-(3,4-dimethylisoxazol-5-yl)piperazine-4-[4-(2-fluoro-4-[11C]methylphenyl)thiazol-2-yl]-1-carboxamide ([11C]DFMC)},
 volume = {373},
 year = {2020}
}