Evaluation of a novel PDE10A PET radioligand, [11C]T‐773, in nonhuman primates: Brain and whole body PET and brain autoradiography. Issue 7 (21st May 2015)

• Record Type: Journal Article
• Authors: Takano, Akihiro; Stepanov, Vladimir; Gulyás, Balázs; Nakao, Ryuji; Amini, Nahid; Miura, Shotaro; Kimura, Haruhide; Taniguchi, Takahiko; Halldin, Christer
• Is Part Of: Synapse. Volume 69:Issue 7(2015:Jul.)
• Page Start: 345
• Page End: 355
• Publication Date: 2015-05-21
• Subjects: kinetics -- dosimetry -- imaging; Synapses -- Periodicals; 612
• DOI: 10.1002/syn.21821
• Languages: English
• ISSNs: 0887-4476

Abstract

ABSTRACT: Phosphodiesterase 10A (PDE10A) is considered to be a key target for the treatment of several neuropsychiatric diseases. The characteristics of [ 11 C]T‐773, a novel positron emission tomography (PET) radioligand with high binding affinity and selectivity for PDE10A, were evaluated in autoradiography and in nonhuman primate (NHP) PET. Brain PET measurements were performed under baseline conditions and after administration of a selective PDE10A inhibitor, MP‐10. Total distribution volume ( V T ) and binding potential ( BP ND ) were calculated using various kinetic models. Whole body PET measurements were performed to calculate the effective dose of [ 11 C]T‐773. Autoradiography studies in postmortem human and monkey brain sections showed high accumulation of [ 11 C]T‐773 in the striatum and substantia nigra which was blocked by MP‐10. Brain PET showed high accumulation of [ 11 C]T‐773 in the striatum, and the data could be fitted using a two tissue compartment model. BP ND was approximately 1.8 in the putamen when the cerebellum was used as the reference region. Approximately 70% of PDE10A binding was occupied by 1.8 mg/kg of MP‐10. Whole body PET showed high accumulation of [ 11 C]T‐773 in the liver, kidney, heart, and brain in the initial phase. The radioligand was partly excreted via bile and the gastrointestinal tract, and partly excreted through the urinary tract. The calculated effective dose was 0.007 mSv/MBq. In conclusion, [ 11 C]T‐773 was demonstrated to be a promising PET radioligand for PDE10A with favorable brain kinetics. Dosimetry results support multiple PET measurements per person in human studies. Further research is required with [ 11 C]T‐773 in order to test the radioligand's potential clinical applications.Synapse 69:345–355, 2015 . © 2015 Wiley Periodicals, Inc. Abstract : A newly developed PET radioligand for phosphodiesterase 10A, [ 11 C]T‐773, has been evaluated in nonhuman primates. [ 11 C]T‐773 has favorable brain kinetics for quantitative analysis, and shows high binding in the striatum, which blocked by MP‐10, a PDE10A inhibitor.